ASP.NET / SQLSERVER

Book for architect

2009-09-22T16:11:00.000-07:00

97 Things Every Software Architect Should Know

Loading large files as attachment in sql server

2009-09-17T10:52:00.000-07:00

CREATE TABLE [dbo].[TEMP_ATTACH](
[DOCID] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
[FILE_NAME] [varchar](200) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
[ATTACHMENT] [varbinary](max) NULL,
[FULL_NAME] [varchar](500) COLLATE SQL_Latin1_General_CP1_CI_AS NULL
) ON [PRIMARY]

declare @path varchar(100)
declare @filename Nvarchar(500)
SET @path = 'C:\Attachments\'
declare att_cursor cursor fast_forward for
select [full_name] from temp_attach

open att_cursor
fetch next from att_cursor into
@filename

while @@fetch_status = 0
begin

EXEC ('UPDATE TEMP_ATTACH
SET ATTACHMENT = BulkColumn
FROM OPENROWSET (BULK ''' + @path + @filename + ''', SINGLE_BLOB) MyFile
WHERE [full_name] = ''' + @filename + '''')

fetch next from att_cursor into
@filename
end
CLOSE att_cursor
DEALLOCATE att_cursor

remove all the options in the dropdown select box.

2009-03-10T07:58:00.000-07:00

Use this JavaScript to remove all the options in the dropdown select box.

document.getElementById('Dropdown').length = 0;

update a table from other table sql server

2009-03-05T08:28:00.001-08:00

update Employee set email = lgfl.xx_email
from DB2.dbo.directEmployee lgfl join Employee on Employee.emp_name = lgfl.emp_name
where Employee.emp_id = dept.emp_id

GridView with BoundField which was setup to format date field with DataFormatString but string formatting is not working

2009-01-27T06:26:00.000-08:00

html encoding is applied by default for the data before it is formatted. Therefore set HtmlEncode="false" to the BoundField so that formatting has expected effect.

http://aspadvice.com/blogs/joteke/archive/2005/09/25/12871.aspx

http://www.netnewsgroups.net/group/microsoft.public.dotnet.framework.aspnet/topic24899.aspx

Finding maximum characters for each filed in a table

2008-11-19T08:30:00.000-08:00

DECLARE
@c varchar(4000),
@t varchar(128),
@maxchars int,
@fieldName varchar(100),
@dynamicSql nvarchar(2000)
SET @c = ''
SET @t='LEGACY_GMM'
SET @maxchars = 0
SET @fieldName = ''
SET @dynamicSql = ''
SELECT @c = @c + c.name + ', '
FROM syscolumns c
INNER JOIN sysobjects o ON o.id = c.id
WHERE o.name = 'LEGACY_GMM' and c.colorder < 101
while charindex(',', @c) > 0
begin
SET @fieldName = substring(@c,0,charindex(',',@c))
SET @dynamicSql = 'select max(len(' + @fieldName + ')) as ' + @fieldName + ' from LEGACY_GMM;'
execute sp_executesql @dynamicSql
SET @c = substring(@c, charindex(',',@c)+1, LEN(@c))
end

Extender Controls

2008-08-14T07:29:00.000-07:00

Extenders are basically controls that reach out and extend other controls.
For e.g. Validation controls, you can add RequiredfieldValidator to the page and associate it to a TextBox control, this extends the Textbox control and changes its behavior.

Notes on ESB (Enterprise service Bus)

2008-08-13T19:55:00.000-07:00

Here are few notes from the ESB talk from channel9.
What is ESB?
It is a solution, it is not a new product.
It utilizes SOA, software factory.

Why you need ESB? What value it brings?

ESB = Infrastructure,
- lot of services
- intelligent routing(sending message to different applications - all in runtime, there should be automatic subscription.)
- Dynamic transformation - what is the map?

Each application has to register to the ESB.
Security - WS* standards implemented in ESB so it is compatible with different vendors.

-Build functional service.
-It should react in short time i.e. it should be Agile, Agile also means one should not build from scratch, instead compose.

- one important thing, SOA is a means and not a goal.
ESB is enabler to SOA

Expose - Compose - Consume.

What is an Architect?

2008-08-13T19:44:00.000-07:00

Here are few notes from the Arcast talk.

What is an Architect?

1) An architect is a Designer.
Strength - Strong Software Engineering fundatmetal.
Functional Structure - software is nothing if it is not useful.
Beautiful - Solution that is pleasing to eyes.

Designer should have a great vision - one should study patterns and apply patterns
SOA + Single signon + integration pattern
WCF = service oriented platform + security + transaction.

2) An architect is an Advocate
He should Listen, observe, think strategically.
Listen to Customers, partners, users, developers.

3) An architect should be an Explorer
Looking for opportunity.
Heading into unknown.
Help business find technology solution to business problem.
as an explorer he has to a) Visionary: technology trends etc. b) Persuasive : Pro / cons of emerging trend. c) Accountable.

Custome Site Map to build menus from Database instead of XML

2008-08-06T15:49:00.000-07:00

We will use the database as shown in fig.
ID, ParentNodeID are integers
rest of the fields are string.

Make following entry in the web.config file.

Now create following class which implements the StaticSitemapProvider

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Collections;
using System.Collections.Specialized;
using System.Data.SqlClient;
using System.Security.Permissions;

///

/// Summary description for SqlSiteMapProvider
///

public class SqlSiteMapProvider : StaticSiteMapProvider
{

private SiteMapNode rootNode = null;
private SqlConnection sqlConnection = null;
private string sp = string.Empty;

// This string is case sensitive.
private string sqlConnectionStringName = "sqlSiteMapConnectionString";

// Implement a default constructor.
public SqlSiteMapProvider() { }

// Some basic state to help track the initialization state of the provider.
private bool initialized = false;
public virtual bool IsInitialized {
get {
return initialized;
}
}
// Return the root node of the current site map.
public override SiteMapNode RootNode {
get {
SiteMapNode temp = null;
temp = BuildSiteMap();
return temp;
}
}
protected override SiteMapNode GetRootNodeCore() {
return RootNode;
}
// Initialize is used to initialize the properties and any state that the
// SqlProvider holds, but is not used to build the site map.
// The site map is built when the BuildSiteMap method is called, it reads the values from the web.config
// in the attributes namevaluecollection.
public override void Initialize(string name, NameValueCollection attributes) {
if (IsInitialized)
return;

base.Initialize(name, attributes);

// Create and test the connection to the Microsoft Access database.

// Retrieve the Value of the Access connection string from the
// attributes NameValueCollection.
string connectionString = attributes[sqlConnectionStringName];
sp = attributes["storedProcedure"];

if (null == connectionString || connectionString.Length == 0)
throw new Exception("The connection string was not found.");
else
sqlConnection = new SqlConnection(connectionString);

initialized = true;
}

///
/// SiteMapProvider and StaticSiteMapProvider methods that this derived class must override.
///
// Clean up any collections or other state that an instance of this may hold.
protected override void Clear() {
lock (this) {
rootNode = null;
base.Clear();
}
}

// Build an in-memory representation from persistent
// storage, and return the root node of the site map.
public override SiteMapNode BuildSiteMap() {

int parentNodeId = 0;
// Since the SiteMap class is static, make sure that it is
// not modified while the site map is built.
lock(this) {

// If there is no initialization, this method is being
// called out of order.
if (! IsInitialized) {
throw new Exception("BuildSiteMap called incorrectly.");
}

// If there is no root node, then there is no site map.
if (null == rootNode) {
// Start with a clean slate
Clear();

// Select the root node of the site map from Microsoft Access.
int rootNodeId = -1;

if (sqlConnection.State == ConnectionState.Closed)
sqlConnection.Open();
SqlCommand rootNodeCommand = sqlConnection.CreateCommand();
rootNodeCommand.CommandText = sp;
rootNodeCommand.CommandType = CommandType.StoredProcedure;
SqlDataReader rootNodeReader = rootNodeCommand.ExecuteReader();

while( rootNodeReader.Read()) {

if (!rootNodeReader.IsDBNull(0))
{
rootNodeId = rootNodeReader.GetInt32(0);
}
// Create a SiteMapNode that references the current StaticSiteMapProvider.
if (rootNodeReader.IsDBNull(4))
{
rootNode = new SiteMapNode(this,
rootNodeId.ToString(),
rootNodeReader.GetString(1),
rootNodeReader.GetString(2),
rootNodeReader.GetString(3));
parentNodeId = rootNodeId;
}
else if (rootNodeReader.GetInt32(4) == parentNodeId)
{
SiteMapNode childNode = new SiteMapNode(this,
rootNodeId.ToString(),
rootNodeReader.GetString(1),
rootNodeReader.GetString(2),
rootNodeReader.GetString(3));
AddNode(childNode, rootNode);
}
else
{
SiteMapNode ch1 = new SiteMapNode(this,
rootNodeId.ToString(),
rootNodeReader.GetString(1),
rootNodeReader.GetString(2),
rootNodeReader.GetString(3));

SiteMapNode parent = FindSiteMapNodeFromKey(rootNodeReader.GetInt32(4).ToString());
AddNode(ch1,parent);
}
}

rootNodeReader.Close();
// Select the child nodes of the root node.

sqlConnection.Close();
}
return rootNode;
}
}

}

WEB PARTS

2008-08-06T06:59:00.000-07:00

- Web Parts are objects in the Portal Framework which the end user can open, close, minimize, maximize, or move from one part of the page to another part.
- Portal Framework defines everything in terms of Zone, there are zones for laying out as well as for editing contents.
- Zones are managed by Framework manager control called WebPartManager.
- WebPartManager completely manages the state of the zones and the content palced in these zones on a per-user basis.
- WebPartManager can also manage the communications between different zones.
- WebPartManager has to be present on every page that works with portal framework, or you can place on the master page.

XML- XSL

2008-08-05T18:33:00.001-07:00

XML – Extensible Markup Language
XSL – Extensible Stylesheet Language
XSL is an XML based language for expressing stylesheets for manipulating XML data.

Xpath, a selection syntax allowing us to select nodes within an XML document. Xpath is used in XSLT to specify which nodes to use in a transformation, and for selecting XML content to include in an output document.

An XSLT stylesheet consists of a series of one or more templates, togather with instructions based on Xpath expressions that tell an XSLT processor how to match the templates against nodes in an XML input document. The result of applying template is another XML document, output could be HTML, or plain text also.

Jing to Capture, record and share

2008-07-31T19:35:00.000-07:00

Tool to Capture Images, Record Videos and Share them online

Reading resources from resource dll of another application

2008-06-20T11:26:00.000-07:00

Copy the Application Dll and Resource dll to one folder.

in the code

Assembly assL = Assembly.LoadFrom(@"C:\Personal\CERT\70-528\MGohil.Services.Authentication.dll");

//here ApplicationTokens is the resource file i.e. ApplicationTokens.resx or ApplicationTokens.en-US.resx
ResourceManager rm = new ResourceManager("MGohil.Services.Authentication.ApplicationTokens", assL);

string t = rm.GetString("XYZ_Key");

Rename database table column SQL Server

2008-06-18T06:59:00.000-07:00

Execute below statemnet in SQL analyzer and it will rename the column name.

exec sp_rename 'DBO.Customers.CompanyName', 'CorporateName', 'COLUMN'

ASP.NET Control Access Key, AssociatedControlID and Underline single character for access key

2008-06-11T12:38:00.000-07:00

Create a local resource file for the corresponding page.

Make an entry in the resource file Name = lblUserNameResource1.Text
and Value = <U>U</U>sername:

and in the ASP.net page for the control use the meta tag instead of text
i.e. meta:resourcekey="lblUserNameResource1"

Reading from Resources.dll in ASP.NET

2008-06-05T10:56:00.000-07:00

Assembly ass = Assembly.LoadFrom(@"C:\CERT\70-528\TestAssembly\MGohil.Services.Authentication.resources.dll");
string strManRes = ass.GetManifestResourceNames()[0]; // use this to get the manifest resource, in next line
Stream str = ass.GetManifestResourceStream("MGohil.Services.Authentication.ApplicationTokens.en-US.resources");

ResourceReader r = new ResourceReader(str);
IDictionaryEnumerator id = r.GetEnumerator();
while (id.MoveNext())
{
Console.WriteLine(id.Key + " - " + id.Value);
}

ServiceController class to interact with windows service

2007-12-10T11:53:00.000-08:00

You can use the ServiceController class to connect to and control the behavior of existing services. When you create an instance of the ServiceController class, you set its properties so it interacts with a specific Windows service. You can then use the class to start, stop, and otherwise manipulate the service.

Environment variable DEVPATH & DevelopmentMode element in configuration section

2007-12-07T07:56:00.000-08:00

DEVPATH: How and why to use it.

Opening a File e.g. PDF, EXCEL, WORDD etc.

2007-12-06T13:38:00.001-08:00

ProcessStartInfo ps = new ProcessStartInfo(@"c:\CERT\ActualTest_070-444_v03.27.07.pdf");
Process pr = new Process();
pr.StartInfo = ps;
pr.Start();

TraceListeners

2007-12-05T08:05:00.000-08:00

Create Listeners like Console, Textwriter and eventlog and add it to the List of listeners of Trace Class, whenever anything in written to Trace or Debug it will be written to all the registered listeners. In order to enable trace and debug, right click the project in visual studio solution explorer and click properties, go to the Build tab and check the boxes against TRACE and DEBUG

using System.Diagnostics;

Stream str = File.Create(@"c:\test_env\log.txt");
TextWriterTraceListener twl = new TextWriterTraceListener(str);
ConsoleTraceListener cwl = new ConsoleTraceListener();

EventSourceCreationData esct = new EventSourceCreationData("", ""); ;
esct.MachineName = ".";
esct.LogName = "Application";
esct.Source = "MyLog";
if (!EventLog.SourceExists("MyLog"))
{
EventLog.CreateEventSource(esct);
}

EventLogTraceListener elt = new EventLogTraceListener("MyLog");

Trace.Listeners.Add(twl);
Trace.Listeners.Add(cwl);
Trace.Listeners.Add(elt);
Debug.WriteLine("Hello Debug");
Trace.WriteLine("Hello Trace");
Trace.Flush();

Code Access Security (CAS) Policy - Tool Caspol.exe

2007-12-03T06:39:00.001-08:00

Security policy is expressed using three policy levels: machine policy, user policy, and enterprise policy. The set of permissions that an assembly receives is determined by the intersection of the permission sets allowed by these three policy levels. Each policy level is represented by a hierarchical structure of code groups. Every code group has a membership condition that determines which code is a member of that group. A named permission set is also associated with each code group. This permission set specifies the permissions the runtime allows code that satisfies the membership condition to have. A code group hierarchy, along with its associated named permission sets, defines and maintains each level of security policy. You can use the–user, -customuser, –machine and -enterprise options to set the level of security policy.

SECUTIL to retrieve public key from assembly.

2007-11-30T10:54:00.001-08:00

secutil -hex -c -s xyz.dll > key.txt

Public Key =
0x00240000048000009400000006020000002400005253413100040000010001
00E373389B3552EFC472D90F0CBE7F55D81FAA9CB7CF9C9332164A3B11B208DCA
2D9D872E610663684D0B664BC222B5B426C6791B09FAC13A1BD52F11AF63421A9
E1721C134904AC2253C6F84A6EB1293770A7AED247DC2D119DE09DF29E4BCAF76
BC941CEAA8528280541A360C7B8D98238E24CFC101C2B90D5CBFE95A35DD7C2
Name =
STNameLib
Version =
1.0.0.0
Success

User friendly name of the owner of the file.

2007-11-30T08:10:00.000-08:00

using System.IO;
using System.Security.Principal;
using System.Security.AccessControl;

FileSecurity fs = File.GetAccessControl(@"C:\CERT\Thinking_in_C_\Thinking in C#.pdf");
NTAccount ntac = fs.GetOwner(typeof(NTAccount)) as NTAccount;
Console.WriteLine(ntac.Value);

Tools for Interoperability between the.NET Framework and COM

2007-11-30T07:36:00.000-08:00

For calling COM APIs from managed code, use Type Library Importer (Tlbimp.exe) which takes a type library as input and outputs a .NET Framework assembly and associated managed metadata.
For calling managed code from COM, use Type Library Exporter (Tlbexp.exe), which takes a managed assembly as input, and generates a type library containing COM definitions of all the public types defined in that assembly.
For calling managed components from COM clients, use Assembly Registration Tool (Regasm.exe), which reads the metadata within a .NET Framework assembly, and adds the registry entries so that COM clients can create managed classes.
For calling ActiveX controls, use Windows Forms ActiveX Control Importer (Aximp.exe), which takes an ActiveX control’s type library as input and generates a wrapper control that allows the control to be hosted in Windows Forms.

Windows Forms ActiveX Control Importer (Aximp.exe)

2007-11-30T07:15:00.000-08:00

The ActiveX Control Importer converts type definitions in a COM type library for an ActiveX control into a Windows Forms control.

Windows Forms can only host Windows Forms controls — that is, classes that are derived from Control. Aximp.exe generates a wrapper class for an ActiveX control that can be hosted on a Windows Form. This allows you to use the same design-time support and programming methodology applicable to other Windows Forms controls.

To host the ActiveX control, you must generate a wrapper control that derives from AxHost. This wrapper control contains an instance of the underlying ActiveX control. It knows how to communicate with the ActiveX control, but it appears as a Windows Forms control. This generated control hosts the ActiveX control and exposes its properties, methods, and events as those of the generated control.

Assembly Registration Tool (Regasm.exe)

2007-11-30T07:00:00.000-08:00

Assembly Registration Tool (Regasm.exe)

The Assembly Registration tool reads the metadata within an assembly and adds the necessary entries to the registry, which allows COM clients to create .NET Framework classes transparently. Once a class is registered, any COM client can use it as though the class were a COM class. The class is registered only once, when the assembly is installed. Instances of classes within the assembly cannot be created from COM until they are actually registered. --

http://msdn2.microsoft.com/en-us/library/tzat5yw6(VS.71).aspx

Attachement as a Linked Resource

2007-11-19T16:20:00.000-08:00

CultureInfo & RegionInfo

2007-11-16T14:34:00.000-08:00

Console.WriteLine("---------Properties of System.Globalization.CultureInfo Class-----------------");
CultureInfo cu = new CultureInfo("hi-IN");
Console.WriteLine("Display Name: {0}",cu.DisplayName);
Console.WriteLine("English Name: {0}",cu.EnglishName);
Console.WriteLine("LCID: {0}", cu.LCID);
Console.WriteLine("Calendar: {0}", cu.Calendar);

Console.WriteLine(Environment.NewLine);
Console.WriteLine("---------Properties of System.Globalization.RegionInfo Class-----------------");
RegionInfo re = new RegionInfo("IN");
Console.WriteLine("Currency English Name: {0}",re.CurrencyEnglishName);
Console.WriteLine("Metric System: {0}",re.IsMetric);

To use Custom Culture or Region use CustomCultureAndRegionInfoBuilder class, for this Add reference to the Dll sysglobal.dll.

Send mail using dot net

2007-11-16T13:24:00.000-08:00

using System.Net;
using System.Net.Mail;

SmtpClient sp = new SmtpClient("smtp.gmail.com", 587);
//sp.Credentials = CredentialCache.DefaultNetworkCredentials;
sp.EnableSsl = true;
sp.Credentials = new NetworkCredential("madhusudan.gohil", "*************");
MailMessage m = new MailMessage("madhusudan.gohil@gmail.com", "ms_gohil@yahoo.com");
m.Attachments.Add(new Attachment(@"c:\amita.jpg"));
m.Subject = "test attach";
try
{

sp.Send(m);

}
catch (Exception ex)
{
Console.WriteLine(ex.StackTrace);
}

Security Tip

2007-11-04T18:40:00.000-08:00

Never pass any value received as a user input to the Control Channel i.e in Command Object in ADO.NET, always build a parameter list i.e. Data Channel. This way one can avoid sql injection.
I.e. if some malicious user passes a drop table statement to the input it won't get executed.

ManagementObjectSearcher

2007-11-03T13:24:00.000-07:00

ManagementObjectSearcher can be used to enumerate all disk drives, network adapters, processes and many more management objects on a system, or to query for all network connections that are up, services that are paused, and so on. When instantiated, an instance of this class takes as input a WMI query represented in an ObjectQuery or its derivatives, and optionally a ManagementScope representing the WMI namespace to execute the query in. Add reference to System.Management dll, sample code

using System.Management;

ManagementObjectSearcher searchService =
new ManagementObjectSearcher("Select * from Win32_Service where state='stopped'");
foreach (ManagementObject svc in searchService.Get())
{
Console.WriteLine(svc["Name"]);
}

ManagementObjectSearcher searchDisk =
new ManagementObjectSearcher("Select * from Win32_Share");
foreach (ManagementObject svc in searchDisk.Get())
{
Console.WriteLine(svc["Name"]);
}

Dot Net Questions

2007-11-02T10:48:00.000-07:00

Q) What is an assembly?
A) Assembly is a primary building block of a .NET Framework application. It is a collection of resources, type definition and implementation of these types in a single unit. The assembly comprises of three entities i.e. IL, Manifest and Metadata. Assemblies are self describing by means of their manifest which is an integral part of assembly.

Q) What is assembly manifest?
A) An assembly manifest is a collection of data (also called metadata of assembly) that contains all the metadata needed to specify the assembly's version requirements and security identity, and all metadata needed to define the scope of the assembly and resolve references to resources and classes.

Q) Information stored in assembly manifest?
A) Assembly name, Version number, Culture, Strong name information (if given), List of all files in assembly, Type reference information, Information of referenced assemblies,

Q) Main function of Assembly manifest?
A) Renders the assembly self describing, enumberates the other assembly on which this assembly depends.

Q) Where are shared Assemblies stored?
A) GAC

Q) Where is global assembly cache located on system.
A) c:\winnt\assembly

Q) What are the ways to deploy an assembly in the GAC?
A) Installer, drag drop to GAC location, use GacUtil.exe a command line tool.

Links for questions and answers
http://aspnet2008.blogspot.com/

Trust Level in Dot Net

2007-10-31T19:58:00.000-07:00

Trust level refers to permission set in the web.config file
"system.web"
"securitypolicy"
"trust level="medium""
"/trust"
"/securitypolicy"
Application operating under a Medium trust level have no registry access, no access to windows eventlog, and cannot use reflection, file system access is limited to the applications virtual directory hierarchy.

Different trust levels
"trust level="Full|High|Medium|Low|Minimal""

ASP.Net 1.1 and 2.0, medium trust application can access SQL server database because SQL Server data provider does not demand full trust and SqlClientPermission is granted to medium trust applications.
In 2.o Oracle .net provider, the OLE DB .NET data provider, ODBC .NET data provider no longer demand full trust.

DOT NET 2.0 Notes Part 3

2007-10-31T13:38:00.000-07:00

Threading

Thread th = new Thread(new ThreadStart(Test));
ThreadStart is a delegate which doesn't take parameter, we can give a reference to the method which do not take any parameter.

Thread.Sleep(3000); //will cause the current thread to sleep for 3 secs, i.e. 3000 ms.
th.Join(); //if any other thread has no finished its task it will block the main thread till the another thread finishes

ThreadPriority Enumeration consists of values that can be use to set or get the thread priority.
ThreadPriority.Highest, ThreadPriority.Lowest, ThreadPriority.Normal etc.

To pass information to the thread use delegate ParameterizedThreadStart
E.g.
//function to be called by the ParameterizedThreadStart
public static void TestParametereized(int i)
{
}
ParameterizedThreadStart pt = new ParameterizedThreadStart(TestParametereized);
Thread thP = new Thread(pt);
thP.Start(10);
// to stop the thread, system prepares ThreadAbortException, whether caught
// or not thread will be stopped.
thP.Abort();

Code between Thread.BeginCriticalRegion(); and Thread.EndCriticalRegion(); is treated as a single line of code, while executing the code between this block if the thread receives a Abort Signal it will complete executing the code between this block and then die throwing ThreadAbortException, this way it will leave the object in a consistent state.

Q) What type of object is required when starting a thread that requires a single parameter?
A) ThreadStart delegate.

Q) What method stops a running thread?
A) Thread.Abort

Sharing Data Multi Threading

Synchronization with windows kernel objects:

Mutex : Allows synchronization (locking mechanism) across AppDomain and Process boundries, e.g. Single instance application.
Semaphore

Event : Provides a way to notify to multiple threads that event has occured.

Mutex, Semaphore, AutoResetEvent, ManualResetEvent all derive from WaitHandle class.

On mutex created with a well-known name, one can use OpenExisting method to get a Mutex that has already been created.

Event class are type of kernel objects that has two states, on and off. These states allow threads across an application to wait until an event is signaled to do something specific.

Asynchronous Programming Model

Three styles to deal with handling of the end of the call in an asynchronous call.
Wait until done
Polling
Callback

Wait until done: Use BeginInvoke methode and pass null for callback and stateobject. E.g. BeginRead of FileStream, call EndInvoke (e.g. EndRead) this will block the thread until the asynchronous call is done.
E.g.
IAsyncResult iResult = fw.BeginRead(buffer,0,buffer.Length,null,null);
int nByteRead = fw.EndRead(iResult); //thread will be blocked, until the asynch is done.

Polling: Use BeginRead and get the reference to AsynchResult, Code will poll IAsyncResult to see whether it is completed.
E.g.
IAsyncResult iResult = fw.BeginRead(buffer,0,buffer.Length,null,null,);
while(!iResult.IsCompleted)
{
Thread.Sleep(1000);
}
Callback Model:

System.Globalization to address the geogrophical scope of the application

Invariant Culture: This culture category is culture-insenistive, useful when creating trial application, not based on English language but is associated with it and bears more similiarity with it.

Neutral Culture: English, French, and Spanish are all neutral culture, a neutral culture is associated with Language but has no relationship to countries or region. A neutral culture is designated by the first two characters in CultureInfo class.

Specific Culture: Most Precise of three, represented by a neutral culture, a hyphen and then a specific culture abbrevation. e.g. fr-FR, en-US.

E.g. to set a culture of current thread.
Thread.CurrentThread.CurrentCulture = new CultureInfo("en-GB");
Console.WriteLine((1000).ToString("C"));

Dot Net 2.0 Notes Part 2

2007-10-31T09:08:00.002-07:00

Serialization

Q) What is serialization?
A) Serialization as implemented in the System.Runtime.Serialization is the process of Serializing and Deserializing objects so that they can stored or transferred and then later recreated.

Q) What is Serializing?
A) Seraializing is a process of converting object into a linear sequence of bytes that can be stored on disk or transferred over network.

Q) What is Deserializing?
A) Deserializing is a process of converting previously serialized sequence of bytes into an object.

E.g. Serializing

FileStream fs = new FileStream(@"c:\test_env\serialized.dat", FileMode.Create, FileAccess.Write);
//binary formatter to perform serialization
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(fs, "This data string will be written to the file as binary data");
fs.Close();

E.g. Deserializing
FileStream fr = new FileStream(@"c:\test_env\serialized.dat", FileMode.Open);
string strIn = string.Empty;
strIn = bf.Deserialize(fr) as string;

Q) How to create a class that can be serialized?
A) If you are satisfied with the default handling of serialization then [Serializable] Attribute to the class is enough, when a class is serialized, runtime serializes all the members including private members.

refer the below example for using various attributes with serialization.

Runtime calls GetObjectData during serialization and serialization constructor during deserialization

[Serializable] //Attribute for serializing and deserializing objects of custom class
class Test:IDeserializationCallback //implement OnDeserialization which will be called once serialization is complete
{
public int i;
public int j;
//total will not be serialized and deserialized, i.e. disable serialization of specific members only.
[NonSerialized] public int total;

//if changes are made to this class, but there are serialized object of
//the instance before this field was added, OptionalField attribute would
//not affect serialization, but during deserialization if the member was not serialized
//it will leave the members value as null rather than throwing exception
[OptionalField] public int offset;

void IDeserializationCallback.OnDeserialization(object sender)
{
total = i + j;
}
}

Two methods for formatting serialized data both of which implement IRemotingFormatter interface.
For BinaryFormatter : Only for .Net Framework
using System.Runtime.Serialization.Formatters.Binary;

For SoapFormatter add reference to "System.Runtime.Serialization.Formatters.Soap" Serialize objects that will be transmitted across network.
using System.Runtime.Serialization.Formatters.Soap;
Consumes 3 to 4 times more space.

XML Serialization:
Can serialize only public data, cannot serialize private data
Cannot serialize graphs, only objects.

E.g.
TestXMLS tm = new TestXMLS(10, 20);
XmlSerializer xm = new XmlSerializer(typeof(TestXMLS));
FileStream fs = File.Create(@"c:\test_env\test.xml");
xm.Serialize(fs, tm);

DOT NET 2.0 Notes Part 1

2007-10-25T11:20:00.001-07:00

Q) What is a Reference Type?
A) Reference type store the address of their data, also known as pointer on the stack, actual data is stored on the Heap.

Q) What are partial Classes?
A) Partial classes allows you to split a class definition accross multiple source files.

Q) Why to use Generics?
A) Casting causes boxing & unboxing which steals processor time and slows performance. Also compiler cannot detect type errors when you cast to and from Object class, instead will throw an runtime exception.

Q)What is an Interface?
A)Interface also known as contract, define common set of members that all classes that implement must provide.

Q) What is an Event?
A) An event is a message sent by an object to signal the occurance of an action.The one that raises the event is called Event Sender and the one that receives is called Event receiver.

Q) What is a Delegate?
A) A delegate is a class that holds reference to a method. A delegate class has a signature and it can hold reference to those method that matches with its signature. It is similar to typesafe pointer or callback.A delegate declaration is sufficient to declare a delegate class.
E.g.
public delegate void ButtonClicked(object sender, EventArgs args);

Note: TryParse, TryParseExact and TryCast are new to NET 2.0 previously you had to attemp parsing or conversion and catch the exception.

Conversion in Custom Type:
Implement System.IConvertible to enable conversion through System.Convert.

FileSystemWatcher Class:
FileSystemWatcher fsw = new FileSystemWatcher(@"c:\test_env");
fsw.NotifyFilter = NotifyFilters.LastWrite;
//WaitForChanged is a Synchronous method for watching a directory
//for changes and for returning a structure that contains all changes.
WaitForChangedResult wcr = fsw.WaitForChanged(WatcherChangeTypes.All);
Console.WriteLine(wcr.Name);

There are events like Created, Changed, Renamed, and Deleted.

File can be opened for writing using following.
File.Open(@"c:\test.txt", FileMode.Create, FileAccess.Write);

Stream class is the abstract base class from which all other stream classes derive from.
FileStream, MemoryStream, CryptoStream, NetworkStream, GZipStream

Different ways to open file for reading or writing using stream classes.
StreamReader sr = File.OpenText(@"c:\test.txt");
StreamWriter sw = File.AppendText(@"c:\test.txt");
FileStream fw = File.OpenWrite(@"c:\test.txt");
FileStream fr = File.OpenRead(@"c:\test.txt");

//reads a stream as a string and not series of bytes.
StreamReader srFile = new StreamReader(@"c:\test.txt");
StreamWriter swFile = new StreamWriter(@"c:\test.txt");

StreamReader is derived from Abstract class TextReader and StreamWriter is derived from Abstract class TextWriter.

StringReader and StringWriter class reads or writes to inmemory strings.

BinaryReader and BinaryWriter:

Creating a binary file:
byte[] bt = new byte[]{95,96,97,98,99};
FileStream fbinw = File.Create(@"c:\temp\test.bin");
fbinw.Write(bt, 0, bt.Length);
fbinw.Flush();
fbinw.Close();

//using binarywriter
BinaryWriter brw = new BinaryWriter(fbinw);
brw.Write(bt);

MemoryStream:
Use StreamReader to read from MemoryStream and StreamWriter to write to MemoryStream.

ArrayList:
Add, AddRange, Insert, InsertRange Methods. Indexers to set item at specific position by overwriting the object at that position.
Remove, RemoveAt, RemoveRange
Clear to empty the collection
Supports IEnumerable interface, which allows to use foreach construct.
Implements interface ICollection derived from IEnumberable and IList derivied from ICollection.

Sequential Lists: Queue and Stack
Queue : FIFO
Stack : LIFO

Dictionary:
Map key to a Value, create a lookup tables.
To iterate using foreach you should cast the object to DictionaryEntry i.e. foreach(DictionaryEntry de in hstLookup).
All dictionary class Supports IDictionary Interface.
IDictionary Interface doesn't allow the access to item by index like IList, but only allows the access by key.
IDictionary Interface has Contains, ContainsKey and ContainsValue

Hashtable
SortedList: To create a list of items that can be sorted by key.

Hashtable is very efficient but has an overhead which for fewer than 10 items can impede performance, very useful for large collection.
ListDictionary: Implemented as simple array of items under the hood, useful for small collection.
HybridDictionary: If you do not know the size, internally it changes the listdictionary to hashtable as the list grows.
OrderdDictionary

BitArray:
No add or remove method, constructor takes the size and initializes all the items with false.
Xor Method of bitarray takes another bitarray object and result is another bitarray which is Xor of two bitarray.

StringCollection is Like an ArrayList except that it accepts only string, passing anything else with cause compilation error.
StringDictionary is like hashtable except that both key and value must be string.

using System.Collections.Specialized;
Hashtable ht = CollectionsUtil.CreateCaseInsensitiveHashtable();
ht.Add("a", "Apple");
ht["A"] = "APPLE";
Console.WriteLine("Count:{0}", ht.Count); // returns one

NameValueCollection appears like a StringDictionary class, but the Add method behaves differently.
The behaviour of Add and indexer is different, indexer will overwrite the previous value if the key supplied is same.

NameValueCollection nv = new NameValueCollection();
nv.Add("A", "apple");
nv.Add("A", "america");

foreach (string st in nv.GetValues("A"))
{
Console.WriteLine("Value for A : {0}", st);
}
Value for A : apple
Value for A : america

Questions:

Q) What type of collections can be made from CollectionsUtil class?
A) Case insensitive Hashtable and Case insensitive SortedList.

Q) What type of values can be stored in StringDictionary?
A) Strings.

undocumented stored procedure for SQL Server

2007-10-24T09:07:00.000-07:00

sp_tempdbspace // without parameter
sp_MStablespace 'xyztable' //with table name.

size returned in MB

.NET 3.5 Language Enhancements

2007-10-24T06:38:00.001-07:00

net-3.5-language-enhancements

Screen scraping OR HTML scraping

2007-10-23T12:42:00.000-07:00

Screen scraping is a technique in which a computer program extracts data from the display output of another program. The program doing the scraping is called a screen scraper.

http://en.wikipedia.org/wiki/Screen_scraping

Microsoft Acropolis

2007-10-22T10:28:00.000-07:00

Microsoft Code Name "Acropolis" is a toolkit for creating modular, business-focused Windows client applications. "Acropolis" builds on the.NET Framework, and includes a run-time framework, design-time tools, and out-of-the-box functionality. "Acropolis" enables you to build reusable, connectable components and assemble them into working applications that are easy to change.

http://windowsclient.net/

http://windowsclient.net/Acropolis/

IIS 7

2007-10-18T13:08:00.000-07:00

In IIS 7.0, bindings can apply to any protocol. The Windows Process Activation Service (WAS) is the new service that makes it possible for IIS 7.0 to use additional protocols.

The Windows Communication Foundation (WCF) programming model is one such technology that can enable communication over the standard protocols of Transmission Control Protocol (TCP), Microsoft Message Queuing (MSMQ), and Named Pipes. This lets applications that use communication protocols take advantage of IIS features, such as process recycling, rapid fail protection, and configuration that were previously only available to HTTP-based applications.

IIS 7.0 supports HTTP and HTTPS by default, but you can use additional protocols.

ApplicationHost.config file (located at %windir%\system32\inetsrv\config \) after installing IIS on Windows Server codename "Longhorn."

New Things in VS2008

2007-10-18T07:46:00.000-07:00

WYSIWYG designer provides:

Split View Support (the ability to have both HTML Source and design open simultaneously)

Extremely rich CSS support (CSS property window, CSS inheritance viewer, CSS preview, and CSS manager)

Dramatically improved view switching performance (moving from source->html design mode is now nearly instantaneous)

Support for control designers within source view (property builders, event wire-up and wizards now work in source view)

Richer ruler and layout support (better yet, values can be automatically stored in external CSS files)

Designer support for nested master pages

Code analysis and code metrics

dot net 3.0 CLR

2007-10-12T11:25:00.000-07:00

.NET 2.0 and 3.0 share the same CLR, everything written in .NET 2.0 works in .NET 3.0
.NET 3.0 = .NET 2.0 + Windows Communication Foundation + Windows Presentation Foundation + Window CardSpace + Workflow Foundation

RSA Alogrithm!!!

2007-10-11T11:50:00.000-07:00

The name RSA is an acronym for the surnames of three inventors of this algorithm: Ron Rivest, Adi Shamir, and Len Adleman. They formed a company, RSA Security, which published several standard documents called Public Key Cryptography Standards (PKCS). These documents describe several aspects of cryptography.

sql server temp table types

2007-05-01T11:52:00.000-07:00

Local temporary tables have a single number sign (#) as the first character of their names; they are visible only to the current connection for the user; and they are deleted when the user disconnects from instances of Microsoft® SQL Server™ 2000. Global temporary tables have two number signs (##) as the first characters of their names; they are visible to any user after they are created; and they are deleted when all users referencing the table disconnect from SQL Server

Sqlserver inbuilt stored procedure

2007-04-17T16:30:00.000-07:00

type sp_help and give the object name, this could be anything table, stored procedure etc.

Dynamic code invocation.

2007-04-13T11:20:00.001-07:00

using System;
using System.Collections.Generic;
using System.Text;
using System.CodeDom.Compiler;
using Microsoft.CSharp;
using System.Reflection;
using System.Configuration;

namespace ReuseCode
{
public abstract class RunTimeMethodInvoker
{
public static object CompliedObject(string strClassCode)
{
ICodeCompiler loCompiler = CodeDomProvider.CreateProvider("csharp").CreateCompiler();
CompilerParameters loParameters = new CompilerParameters();
//this is the path where the complier will look for the referenced libaray
//loParameters.CompilerOptions = "/debug /lib:" + ConfigurationManager.AppSettings["InstallationPath"];
loParameters.ReferencedAssemblies.Add("System.dll");

// *** Load the resulting assembly into memory
loParameters.GenerateInMemory = true;

// *** Now compile the whole thing
CompilerResults loCompiled = loCompiler.CompileAssemblyFromSource(loParameters, strClassCode);

if (loCompiled.Errors.HasErrors)
{
string lcErrorMsg = "";

// *** Create Error String
lcErrorMsg = loCompiled.Errors.Count.ToString() + " Errors:";
for (int x = 0; x < loCompiled.Errors.Count; x++)
lcErrorMsg = lcErrorMsg + "\r\nLine: " + loCompiled.Errors[x].Line.ToString() + " - " +
loCompiled.Errors[x].ErrorText;

return null;
}

Assembly loAssembly = loCompiled.CompiledAssembly;

//object loObject = loAssembly.CreateInstance("Delphi.PassPods.SeatParser.CDynamicSeatDataFieldFormatter");
object loObject = loAssembly.CreateInstance("TestClass");

return loObject;
}

public static object RuntimeMethodCall(object loObject, string strFunctionName,
object[] loCodeParms)
{
object loResult = null;

loResult = loObject.GetType().InvokeMember(strFunctionName,
BindingFlags.InvokeMethod, null, loObject, loCodeParms);
return loResult;
}
}

class Program
{
static void Main(string[] args)
{
TestDynamicCode();
}

static void TestDynamicCode()
{
string strTest = "using System; using System.IO; public class TestClass { public string outputResult() { return \"hello from test\"; }}";

// *** Retrieve an object reference - since this object is 'dynamic' we can't explicitly
// *** type it so it's of type Object
object loObject = RunTimeMethodInvoker.CompliedObject(strTest);
object loResult = RunTimeMethodInvoker.RuntimeMethodCall(loObject, "outputResult", null);

Console.WriteLine(loResult.ToString());
}
}

}

Windows PowerShell

2007-04-12T18:44:00.000-07:00

CASE STATEMENT IN SQL SERVER

2007-04-10T18:53:00.000-07:00

update bladder_data set plant_id =
case
when charindex('M',bladder_barcode,3) > 3 and charindex('M',bladder_barcode,3) < (len(bladder_barcode)-8) then 3 else 4 end

Postback Trace Events

2007-04-09T17:09:00.000-07:00

Trace Page Life Cycle

2007-04-09T17:04:00.000-07:00

Series of events in page life cycle

2007-04-09T16:58:00.000-07:00

Series of events
PreInit
Init
PreLoad
Load
PreRender
Unload

Saving large text to database field.

2007-03-31T12:17:00.000-07:00

System.Runtime.Serialization.Formatters.Binary.BinaryFormatter bf = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
MemoryStream mr = new MemoryStream();
bf.Serialize(mr, strCode);
byte[] bt = mr.GetBuffer();

assign this bt to the param.Value to be passed to the sqlhelper.

Retrieving a large text stored as binary in the database.

2007-03-31T12:14:00.000-07:00

- SQLHelper.ExecuteScalar would return an object.
- System.Runtime.Serialization.Formatters.Binary.BinaryFormatter bf_1 = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
MemoryStream mr_1 = new MemoryStream(objClassCode as Byte[]);
//retrieve the code from the database and assign to the variable.
string strText = bf_1.Deserialize(mr_1).ToString();
mr_1.Close();

string.Join

2007-03-30T19:55:00.000-07:00

it will recreate a single string from an array of string, give a separator to create string with separator.

Windows CardSpace

2007-03-28T15:11:00.001-07:00

http://en.wikipedia.org/wiki/Windows_CardSpace

Replace special characters in the file name

2007-03-21T11:49:00.000-07:00

string strTest = "abcd@efg";
string strPattern = @"#/\?*#";
Regex rg = new Regex(strPattern);
if (rg.IsMatch(strTest))
{
//replaces invalid chars with __
_fileNameWithSpecialCharsReplaced = rg.Replace(value, "__");
}

Replace spaces with underscore in a string

2007-03-21T11:45:00.000-07:00

using System.Text.RegularExpressions;

Regex reg = new Regex(@"\s");
string strTest = "hello how are you";
string strout = reg.Replace(strTest, "_");

DTS IMPORT / EXPORT GIVES ERROR

2007-03-16T12:33:00.000-07:00

Resloved using the below solution.

Run the svrnetcn.exe on which MSDE is installed, SQL Server Network Utility Dialogbox will be displayed,Make sure that TCP/IP is enabled and the port is 1433.

MSDE Limitations

2007-03-13T09:55:00.000-07:00

An MSDE database can be no larger than 2 GB (this includes MDF and NDF files only â€” log sizes are not included in the size limit);

MSDE does not support SQL Mail

As of July 2004, these are the planned limitations of the next generation of MSDE, now known as SQL Server Express (which will still be a free product):
1 GB memory (for buffer, not total);
1 CPU;
50 named instances per machine;
4 GB per database (not including log files);

sql server utility to do bulk copy / insert

2007-03-12T12:49:00.000-07:00

bcp "table name" out "file path" -S ServerName -U username -P Password -k -c -E -q
(see the bcp command help by typing bcp on command promp)

bcp seat_data_core out c:\core.txt -S DLG6BVV81 -U PodsUser -P pods -k -c -E -q
bcp seat_data_stage_2 out c:\stage2.txt -S DLG6BVV81 -U PodsUser -P pods -k -c -E -q
bcp seat_extra_data out c:\extra.txt -S DLG6BVV81 -U PodsUser -P pods -k -c -E -q

bcp seat_data_stage_2 in c:\stage2.txt -S usmitry-db09 -U PodsUser -P pods -k -c -E -q
bcp seat_extra_data in c:\extra.txt -S usmitry-db09 -U PodsUser -P pods -k -c -E -q