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Showing posts from November, 2014

Using the DropDownList Helper with ASP.NET MVC

This post will teach you the basics of working with the DropDownList helper helper in an ASP.NET MVC Web application.
The DropDownList helper used to create an HTML select list requires a IEnumerable , either explicitly or implicitly. That is, you can pass the IEnumerable explicitly to the DropDownList helper or you can add the IEnumerable to the ViewBag using the same name for the SelectListItem as the model property.
Let's suppose you want to show list of Animals as dropdownlist

publicstatic List<String> GetPets() { List<string> petList = new List<string>(); petList.Add("Dog"); petList.Add("Cat"); petList.Add("Hamster"); petList.Add("Parrot"); petList.Add("Gold fish"); petList.Add("Mountain lion"); petList.Add("Elephant"); return petList; }
Open your controller met…

How to create html helper in razor (.NET MVC)

Razor is an ASP.NET programming syntax used to create dynamic web pages with the C# or Visual Basic .NET programming languages.The Razor syntax is a template markup syntax, based on the C# programming language, that enables the programmer to use an HTML construction workflow[clarification needed]. Instead of using the ASP.NET .ASPX markup syntax with <%= %> symbols to indicate code blocks, Razor syntax starts code blocks with a @ character and does not require explicit closing of the code-block.

HTML Helper
Html helper are much like asp.net control that return html string.But HTML helpers are more lightweight. Unlike Web Form controls, an HTML helper does not have an event model and a view state.
In this post I will show you how to create Html helper in MVC.NET.There are two ways to create html helper in MVC.
Inline Helpers
These are create in the same view by using the Razor @helper tag. These helpers can be reused only on the same view.For example in following code snippet I ha…

How to check stream has Image or not

Let's suppose you have a page on which user upload there image and you want to validate that user is uploading image file only not other file format.The one easy solution is use regex and validate the extension of the file but if user rename the extension of the file and upload some executable code.Following is the simple c# code snippet that check the file type by the header value.
privatebool IsImage() { bool isImage = false; FileStream stream = new FileStream(Server.MapPath(@"Images\a.txt"), FileMode.Open, FileAccess.Read); StreamReader reader = new StreamReader(stream); // Read the first 25 characters, we will be checking for a GIF or JPG signature.char[] strBuffer = newchar[25]; reader.ReadBlock(strBuffer, 0, 25); string stringBuffer = newstring(strBuffer); // Is this an image?if (stringBuffer.IndexOf("GIF8") &gt; -1 || stringBuffer.IndexOf("JFIF") &gt; -1) { i…

How To Change your ASP.Net controls at runtime

Lets say you are working in a fairly large asp.net application. Now because of situation (or clients request) you want to change all the textbox or button control to some server control or user control. This can be very very tedious JOB if you are using Asp.net 1.X. But if you are using Asp.net 2.0 , there is a very easy way to get this done using tagMapping
it’s a way to turn all instances of a type into another type at compile time. In human language it means that it can turn all e.g. System.Web.UI.WebControls.Textbox (in our example ) instances in the entire website into another control.That is so cool that I had to do a little example. I’ve created a very simple control that inherits from a TextBox and overrides the Text property so that it HTML encodes the text. I placed it in the App_Code folder and called it SafeTextBox.

using System; using System.Data; using System.Configuration; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; …

How to change some text before it is sent to the client.

In this post,I will show you how to modify the response before it is sent to the client.The trick here is to override the Render method of the Page class and modify the response.
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="InterceptHtml.aspx.cs" Inherits="InterceptHtml" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>Untitled Page</title> </head> <body> <form id="form1" runat="server"> <div> Hello World! <br /> Hi </div> </form> </body> </html>
using System; using System.Data; using System.Configuration; using System.Collections; using System.Web; using System.Web.Security; using Syst…

How to return data from ajax call

In this post,I will show you how to return data from ajax request.As you know that you can not return data from ajax request but if you want to perform some action on return data of ajax.The better approach is to organize your code properly around callbacks. In the example,you can make GetUsers accept a callback and use it as success callback.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ReturnAjax.aspx.cs" Inherits="ReturnAjax" %><!DOCTYPEhtmlPUBLIC"-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><htmlxmlns="http://www.w3.org/1999/xhtml"><headrunat="server"><scripttype="text/javascript"src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js"></script> <title></title> <script type="text/javascript"> $(document).ready(function () {�����…

How To Convert HTML to Text, Easily

Whether you want to convert an HTML page into pure text so you can parse out that special piece of information, or you simply want to load a page from the Net into your own word processing package, this mini function could come in handy. It’s called StripTags and accepts an HTML string. Using a regular expression, it identifies all <tags>, removes them, and returns the modified string. Here’s the code: <%@ Page Language="C#" ValidateRequest="False" AutoEventWireup="true" CodeFile="StripTag.aspx.cs" Inherits="StripTag" %><!DOCTYPEhtmlPUBLIC"-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><htmlxmlns="http://www.w3.org/1999/xhtml"><headrunat="server"><title>Untitled Page</title></head><body><formid="form1"runat="server"><div><asp:TextBoxID="TextBox1&quo…

How to change default binding in wcf 4.0

In this post I will share a very handy tips for wcf 4.0.As we all know that default binding is a new feature introduced in wcf 4.0.With WCF 4, this is no longer the case because the runtime automatically adds one or more "default endpoints" for you, thereby making the service usable without any configuration.
<protocolMapping><addbinding="wsHttpBinding"scheme="http"/></protocolMapping>