The simplest Asp.net Ajax post is suitable for beginners.

Today I will share with you the "simplest Asp.net Ajax Post", which is only applicable to beginners.

Opening lecture:

As we all know, Ajax is generally used for Asp.net to achieve the effect of refreshing data. There is also a lot of information on the Internet, but I want to record this simple example, so I came to the blog Park to write an essay...

Check the front-endCode:

HTML and JS

 <%  @ Page Language  =  "  C #  " Autoeventwireup  =  "  True  "  Codebehind  =  "  Index. aspx. CS  "  Inherits  = "  Jquery. admin. Index  "   %> 

 <!  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  > Demo </  Title  > 
 <  Link  Href  = "CSS/adminindex.css"  REL = "Stylesheet"  Type  = "Text/CSS"   /> 
 <  Script  Type  = "Text/JavaScript"  >  
  //  Create xhlhttprequest  
  Function Creatxmlhttprequest ()
{
  //  IE browser  
  If  (Window. activexobject)
{
  Return   New  Activexobject (  "  Microsoft. XMLHTTP "  );
}
  Else  
{
  Return   New  XMLHttpRequest ();
}
}

  //  Click  
  Function Lookuser ()
{
  VaR  Xhr  =  Creatxmlhttprequest ();
  VaR  URL  =   "  Getdata. ashx  " ;
  VaR  ID  =  Document. getelementbyid (  "  Txtuserid  "  ). Value;
  //  Concatenates a string to the backend for processing.ProgramAnd must be transcoded using escape. Otherwise, garbled characters may occur. 
  VaR  Canshu  =   "  Userid =  "   +  Escape (ID );
  //  Method of execution after successful processing  
 Xhr. onreadystatechange  =   Function  ()
{
  If  (Xhr. readystate  =   4   &&  Xhr. Status  =  200  )
{
Document. getelementbyid (  "  Userinfo  "  ). Innerhtml  =  Xhr. responsetext;
}
}
Xhr. Open (  "  Post "  , URL,  True  );
  //  The header information can be called by the server through post.  
  Xhr. setRequestHeader (  "  Content-Type  " ,  "  Application/X-WWW-form-urlencoded  "  );
  //  Send request  
  Xhr. Send (canshu );
}
  </  Script  > 
</  Head  > 
 <  Body  > 
 <  Form  ID  = "Form1"  Runat  = "Server"  > 
 <  ASP: textbox  ID = "Txtuserid"  Runat  = "Server"  Width  = "150px"  Height  = "22px"  > </  ASP: textbox  >  & Nbsp; 
 <  Button  Type  = "Button"  Onclick = "Lookuser ()"  Style  = "Height: 30px; width: 80px ;"  > View users </  Button  > <  BR  /> <  BR  /> 
 <  Div  ID  = "Userinfo"  > 
</  Div  > 
 </  Form  > 
 </  Body  > 
 </  Html  > 

One getdata. ashx is used to process the program and returns a string.

Effect

It's very simple. There's nothing to say, that's it...

PS: Tandy tang I wish you a pleasant time writing code in the New Year (2012!