Asynchronous Methods PART-2

Everybody would agree that asynchronously-served requests are important for the performance of potentially-lengthy operations. Taking this point to the limit, Windows 8 is highly dependent upon asynchronous operations and that is the preferred way of coding in the newest platform.

So what’s the real benefit of implementing asynchronous requests?

The benefits of asynchronous requests are entirely for the server environment. In ASP.NET, async HTTP handlers keep the server runtime much more responsive by guaranteeing that a larger number of threads are available at any time to serve requests. In the end, it won’t so much be the requests for long-running tasks that benefit from async handlers, but all other requests, for images, scripts, and other static and ASPX pages. In this way, the site remains highly responsive for all users and long-running requests will still take their time to complete. 

Asynchronous Methods PART-1

In general, use synchronous methods for the following conditions:

• The operations are simple or short-running.
• Simplicity is more important than efficiency.
• The operations are primarily CPU operations instead of operations that involve extensive disk or network overhead. Using asynchronous methods on CPU bound operations provides no benefits and results in more overhead.
• In general, use asynchronous methods for the following conditions:
• You're calling services that can be consumed through asynchronous methods, and you're using .NET 4.5 or higher.

 

• The operations are network-bound or I/O-bound instead of CPU-bound.
• Parallelism is more important than simplicity of code.
• You want to provide a mechanism that lets users cancel a long-running request.
• When the benefit of switching threads out weights the cost of the context switch. In general, you should make a method asynchronous if the synchronous method blocks the ASP.NET request thread while doing no work.  By making the call asynchronous,  the ASP.NET request thread is not blocked doing no work while it waits for the web service request to complete.
• Testing shows that the blocking operations are a bottleneck in site performance and that IIS can service more requests by using asynchronous methods for these blocking calls.

C# Event Handlers and Delegates

C# Event Handlers and Delegates in ASP .Net with Web User Controls

This article should help as a general how to on event handlers and delegates in C# as well as propose a different way to handle cross page methods in your ASP .Net website from a web user control or other page.

Create event handlers and their delegates in the user control, fire them from the methods tied to the internal controls protected events, and define the methods that will handle the new events in the page (see code below).

This article should help as a general how to on event handlers and delegates in C# as well as propose a different way to handle cross page methods in your ASP .Net website from a web user control or other page.

Popup window

Here I am going make custom model popup with using JQuery. Its looks very Attractive rather than the simple alert box in Asp.Net.

In my application, i would like to use the popup window concept. When the user clciks a button, a popup window should appear, with a textbox to enter a value. on closing the popup window, the user entered value should get saved into a table.

.Net C# How to dynamically add controls to a form

Dynamically Adding Controls to a Windows Form

I have a project right now who’s requirements are to dynamically create sections on a form, dynamically create items in those sections (checkboxes, text boxes, etc), and store the values entered in those boxes in a database.

Now this is no small task, but it had me thinking. It’s been a while since I wrote something that used dynamic controls. Since I’m writing the code anyway I thought I would share the technical details as to how you too can create your own controls on the fly, and hook up the events, and read the data. So many web demo’s seem to show the first and miss the next two (which would be the same as missing the point entirely..)

Create Html Table Dynamically

The following code dynamically creates a table with five rows and four cells per
row, sets their colors and text, and shows all this on the page. The interesting detail is that no control tags are declared in the .aspx file. Instead, everything is generated programmatically.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

public partial class DynamicTable : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        HtmlTable table1 = new HtmlTable();

        // Set the table's formatting-related properties.
        table1.Border = 1;
        table1.CellPadding = 0;
        table1.CellSpacing = 0;
        table1.BorderColor = "red";

        // Start adding content to the table.
        HtmlTableRow row;
        HtmlTableCell cell;
        for (int i = 1; i <= 3; i++)
        {
            // Create a new row and set its background color.
            row = new HtmlTableRow();
            row.BgColor = (i % 2 == 0 ? "lightgreen" : "lightgray");
            for (int j = 1; j <= 5; j++)
            {
                // Create a cell and set its text.
                cell = new HtmlTableCell();
                cell.InnerHtml = "Row: " + i.ToString() + "<br />Cell: " + j.ToString();
                // Add the cell to the current row.
                row.Cells.Add(cell);
            }

            // Add the row to the table.
            table1.Rows.Add(row);
        }

        // Add the table to the page.
        this.Controls.Add(table1);
    }
}

UpdateProgress in Asp.Net

One of the problems with Ajax, is the fact that since it's asynchronus and in the background, the browser will not show you any status. With fast servers and fast methods, this is not a big problem, but whenever you have a method which takes up a bit of time, the user is very likely to get impatient.

Fortunately, ASP.NET AJAX solves this problem for us as well, with a nice control called UpdateProgress. It will use your own template to show that an asynchronus method is working. Have a look at the following example, which will show the control in action. It will be explained afterwards.

How To Keep ASP.NET ViewState On The Server

During recent few engagements with my customers I've noticed  VIewState is extensively [unintentionally] used. ViewState is on by default. The result is heavy weight Html that round trips on the network. This causes slow response time and high network utilization that affects another applications using the same network.

How to remove ViewState from the network completely while taking an advantage if its functionality at same time?

Server Explorer

The Server Explorer in VS .NET may look very familiar to users of Visual InterDev. Visual InterDev shipped with a feature allowing developers to access and manipulate remote data sources, all in an integrated part of the IDE. The Server Explorer in VS .NET provides this functionality and adds a whole lot of its own. A full list of resources that you can access with the Server Explorer follows.

Class View

The Class View is displayed by selecting the Class View option from the View menu. The Class View shows all the classes that apply to the project, including those in the project’s References and Web References, as well as classes that the project itself owns (each Web Form is in itself a class).

The Class View is a powerful tool and provides a constructive and useful overview of a solution. Members of classes, such as methods and properties, are represented as child nodes in the Class View treeview, and their respective scopes are shown through the use of icons.

RAISERROR statement in SQL server

RAISERROR statement is used to return error messages to the business applications that executes SQL statements. The usual errors returned by the SQL server may not make much sense to the business applications users hence we overwrite it by using RAISERROR to display meaningful messages. The statement uses same format as a system error or warning messages generated by SQL server.

You can return a user-defined error message by using RAISERROR.  The general syntax is as below

Creating a UserControl

we will be building a UserControl for displaying information about a community user.
First of all, let's add a UserControl to our project. In your Visual Studio or Visual Web Developer, you should be able to right click on your project and select Add new item.. A dialog will pop up, and you should select the Web User Control from the list of possible things to add. Let's call our UserControl UserInfoBoxControl, with the filename of UserInfoBoxControl.ascx. Make sure that you have checked the checkbox which places code in a separate file, the so-called CodeBehind file.

You should now have a UserInfoBoxControl.ascx and a UserInfoBoxControl.ascx.cs in your project. The first is where we put our markup, and the second is our CodeBehind file. Now, if UserInfoBoxControl.ascx is not already open and selected, do so now. You will see only one line of code, the UserControl declaration. As mentioned, this control will be displaying information about a user, so let's get started adding some markup to do so:

ASP.net Ajax

ASP.net Ajax is Microsoft's free framework for creating Ajax (Asynchronous Javascript and XML) web applications. At its simplest, it lets ASP developers do this - or add Ajax controls to their existing applications - without leaving their familiar drag-and-drop environment, and without having to understand Javascript or asynchronous communication with the host. According to the O'Reilly Network, it protects developers from "the underlying gibberish that makes it [Ajax] all work".