Disable Button While Processing a Request in Asp.Net

I have been looking into a problem of disabling a button when user clicked to prevent the multiple clicks. Finally I got a solution.

I tried to disable the button in client side by writing a piece of javascript code, but it doesnt work. If we want this in client side, we need to do all the validations and all other client side stuffs manually.

This is a tricky logic, if you have eny better idea please share.
Add the following html code.

<asp:Button ID="btnSearch" CssClass="button" runat="server" Text="Search" 

onclick="btnSearch_Click" />

<div style="display:none">

<asp:Button ID="btnSearch1" CssClass="button" runat="server" Text="Search" 

onclick="btnSearch1_Click" />

</div>

Add the following javascript in your aspx page

<script type= "text/javascript">

function postSearchData() {

jQuery(document).ready(function () {

jQuery("#btnSearch1").trigger("click");

});

}

</script>

Add the Buttons event handlers

protected void btnSearch_Click(object sender, EventArgs e)

{

btnSearch.Enabled = false;

Page.ClientScript.RegisterClientScriptBlock(typeof(Label), "postback", "postSearchData();", true); 

}

protected void btnSearch1_Click(object sender, EventArgs e)

{

System.Threading.Thread.Sleep(5000);// remove this line
// do your operations here.
btnSearch.Enabled = true;

}

In the above example btnSearch is associateed with all validation controls and it does the validations. When user clicks on it it cause a postback and disable it, a piece of javascript code is written to the page after the postback to automatically fire the btnSearch1 button's click event. btnSearch1 will remain always hidden.

Hope this will help you, do not hesitate to share your comments.

FILESTREAM in Sql Server 2008 and Example

FILESTREAM in SQL Server 2008

SQL Server 2008 introduces the new FILESTREAM attribute, which can be applied to the varbinary(max) data type. Using FILESTREAM, you can exceed the 2GB limit on stored values and take advantage of relational handling of files via SQL Server, while actually storing the files on the file system. BACKUP and RESTORE operations maintain both the database data as well as the files saved on the file system, thus handling end-to-end data recoverability for applications that store both structured and unstructured data. FILESTREAM marries the transactional consistency capabilities of SQL Server with the performance advantages of NT file system streaming.

SQL Server can manage the contents of the FILESTREAM containers on the file system for you and control access to the files, while the NT File System (NTFS) provides efficient file streaming and file system transaction support. This combination of SQL Server and NTFS functionality provides several advantages when dealing with LOB data, including increased efficiency, manageability, and concurrency.

Check whether the filestream property is enabled or not. To do this executes the following query.

SELECT SERVERPROPERTY('FilestreamShareName') ShareName,
SERVERPROPERTY('FilestreamEffectiveLevel') EffectiveLevel,
SERVERPROPERTY('FilestreamConfiguredLevel') ConfiguredLevel

If it is not enable use sp_configure procedure to enable it.

EXEC sp_ configure 'filestream access level', 2;
GO
RECONFIGURE;
GO

FILESTREAM Access Levels:


0. Disable

1. Access via T-SQL only

2. Access via T-SQL only and file system

Once you’ve enabled FILESTREAM support on your SQL Server instance, you have to create a SQL Server file group with the CONTAINS FILESTREAM option. This file group is where SQL Server will store FILESTREAM BLOB files.

Example:

CREATE DATABASE Jobin ON PRIMARY
(
NAME='Jobin_Data',
FILENAME='E:\Jobin\sql\jobin.mdf'
),
FILEGROUP DocumentFileStreamGroup CONTAINS FILESTREAM
(
NAME='FileStreamdocuments',
FILENAME='E:\Jobin\sql\jobin_documents'
)
LOG ON
(
NAME='Jobin_Log',
FILENAME='E:\Jobin\sql\jobin.ldf'
);

To enable FileStream to an existing database execute the following query

-- to add filestream to an existing database
ALTER DATABASE Jobin
ADD FILEGROUP DocumentFileStreamGroup CONTAINS FILESTREAM;
GO
ALTER DATABASE Jobin
ADD FILE
(
NAME = 'FileStreamdocuments'
FILENAME = 'E:\Jobin\sql\jobin_documents'
)
TO FILEGROUP DocumentFileStreamGroup;

FILESTREAM Enabled Tables


Once you’ve enabled FILESTREAM on the server instance and created a FILESTREAM filegroup, you’re ready to create FILESTREAM-enabled tables. FILESTREAM storage is accessed by creating a varbinary (max) column in a table with the FILESTREAM attribute. The FILESTREAM-enabled table must also have a uniqueidentifier column with a ROWGUIDCOL attribute.

CREATE TABLE Employee
(
EmpId UNIQUEIDENTIFIER ROWGUIDCOL PRIMARY KEY,
Name VARCHAR(50),
Document VARBINARY(MAX) FILESTREAM
)

Insert some records into the table.

INSERT INTO Employee VALUES(NEWID(),'Jobin',CAST('jobin john' AS VARBINARY(MAX)));
INSERT INTO Employee VALUES(NEWID(),'Ajith',CAST('Software Engineer' AS VARBINARY(MAX)));

Select the inserted values

SELECT * FROM Employee
SELECT EmpId,Name,CAST(Document AS VARCHAR) AS Document FROM Employee

Introducing Microsoft Visual Studio LightSwitch 2011

Microsoft Visual Studio LightSwitch 2011

Microsoft Visual Studio LightSwitch is a simplified self-service development tool that enables you to build business applications quickly and easily for the desktop and cloud or it is a development tool that helps you build business applications quickly. LightSwitch provides a simplified development environment that enables you to concentrate on the business logic instead of the application infrastructure.

LightSwitch heps us to develop business applications simply and fastly. LightSwitch is optimized around making data and screens, this would reduce the development effort.

Microsoft Visual Studio LightSwitch uses a model-centric architecture for defining, building, and executing a LightSwitch application.

Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property

Fix JSON serialization error by setting maxJsonLength.

This error is occured when serialize an object in JSON string by JavaScriptSerializer class, it will throw this exception if object contains too many records(data). We can fix this issue by setting maxJsonLength in web.config file.
Exception type: InvalidOperationException
Exception message: Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property.

<configuration>
     <system.web.extensions>
        <scripting>
            <webServices>
                <jsonSerialization maxJsonLength="50000000"/>
            </webServices>
        </scripting>
    </system.web.extensions>
 </configuration> .

Software Development Tips and Tricks & Tutorials

Software Development is the process of creating or developing a quality application which will help the business to grow.

Software development process includes the following steps.

• Understanding the business or Domain : Now you may have a question that "Why should I know the business/domain?. As a programmer my job is only writing codes and developing the application. then why?". The answer is very simple, if you are aware on the domain, I would say it is definitely an added advantage to the software development process.
• Understanding requirements: Understanding client requirement is one of the important factor in software development.
• Design: Once we completed the requirement analysis, next we need to design the application. Mostly its done by creating a high level design document and low level design document.
• Development: Develop the application based on the design document and functional requirement document. While do coding ensure all business validations and requirements are under coverage.
• Testing: Testing is an investigation conducted to provide the information about the quality of the product/application.
• Implementation: In this step, we will be deploying the final solution/application which is tested and completed on to the server. While deploying/releasing we will also develop a release document which will help the end user to deploy the application in their enviornment.
• Maintanance: Maintanance is the modification of a software product after delivery to correct faults or to improve performance.

I hope now you are clear on the Software Development Life Cycle (SDLC) mentioned above.

Here are some Tips and Tricks that might be improve the quality of software development

• Love your profession
• Simplify the complex logic by splitting.
• Be an innovator and expert in technology
• Be a good learner
• Be aware of latest technologies
• Learn the process
• Minimum amount of sleep should be 6 hours
• Be social
• Enjoy holidays and free time
• Involve in any games during work hours
• Think positively.

Using server-side state management in Asp.Net

Using server-side state management

ASP.NET provides two ways to store state on the server and thus share information between Web pages without sending the data to the client. These two methods are referred to as application state and session state. Application state information is global to the application. It is available to all pages regardless of the user requesting the page. Session state is user-specific state that is stored by the server. It is available only to pages accessed by a single user during a visit to your site.

Application State

Application state in ASP.NET is a global storage mechanism for state data that needs to be accessible to all pages in a given Web application. Application state is optional; it is often not required.

You store application state in an instance of the HttpApplicationState class that is provided through the Page.Application property. This class represents a key–value dictionary, where each value is stored and accessed by its key (or name). You can add to and read from the application state from any page on the server.

Eg: place a button and write the following code.

Application["a"] = Convert.ToInt32(Application["a"]) + 1;
Response.Write("Application value = "+Application["a"]);

Session State

Most Web applications need to store user-specific data between individual requests.

Session state can be thought of in a similar way as application state. The big difference is that session state is scoped to the current browser (or user) session and only available to that session (and not the entire application).

Reading and Writing Session State Data:

You store user-specific session state in the Session object. This is an instance of the HttpSessionState class and represents a key–value dictionary collection. Items are added, updated, and read in a similar manner as working with any .NET dictionary collection.

Eg: place a button and write the following code.

Session["a"] = Convert.ToInt32(Session["a"]) + 1;
Response.Write("Session value = "+Session["a"]);

Disabling Session State

If you don’t use session state, you can improve performance by disabling it for the entire application. You do so by setting the sessionState mode property to Off in the Web.config file. The following shows an example:

<configuration>
<system.web>
<sessionState mode="off"/>
</system.web>
</configuration>

You can also disable session state for a single page of an application by setting the EnableSessionState page directive to False. You can also set the EnableSessionState page directive to ReadOnly to provide read-only access to session variables for the given page.

Eg:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs"
Inherits="_Default" EnableSessionState = "False"%>

Configuring Cookieless Session State


By default, session state uses cookies to track user sessions. This is the best choice for the vast majority of applications. All modern Web browsers support cookies. However, users can turn them off. Therefore, ASP.NET allows you to enable cookieless session state.

Without cookies, ASP.NET tracks sessions using the URL by embedding the session ID in the URL after the application name and before any remaining file or virtual directory identifier.

You enable cookieless sessions through the Web.config file. Set the cookieless attribute of the sessionState element to true.

<configuration>
    <system.web>
      <sessionState cookieless="true"
      regenerateExpiredSessionId="true" />
    </system.web>
  </configuration>

Choosing a Session State Mode

ASP.NET provides a few different session management modes for your application.

InProc: Stores session state in memory on the Web server. This is the default mode. It offers much better performance than using the ASP.NET State Service or storing state information in a database server.

StateServer: Stores session state in a service called the ASP.NET State Service. This ensures that session state is preserved if the Web application is restarted and also makes session state available to multiple Web servers in a Web farm.

SQLServer: Stores session state in a SQL Server database. This ensures that session state is preserved if the Web application is restarted and also makes session state available to multiple servers in a Web farm.

Custom: Enables you to specify a custom session state storage provider. You also need to implement (code) the custom storage provider.

Off: Disables session state. You should disable session state if you are not using it to improve performance.