03-22 Ajax verification user logon, 03-22ajax

03-22 Ajax verification user logon, 03-22ajax

In a webpage, data is usually submitted through a form, and the form obtains information, discarding the current page and reloading a new page.

Now, you can use JueryAjax to submit and process data on the webform webpage to asynchronously refresh the page.

What is the difference between form-submitted data and JueryAjax-submitted data:

Form	Form to get information, discard the current page and reload a new page. (Only submit data)
JueryAjax	Submit data, send it out, and then obtain data and update information without refreshing the page. (Submit and report back)

Take verifying that the user name is repeated as an example:

Write a function in Html:

1 document. ready {}: trigger function content 2 $ document. ready (3 {4 function () // obtain the value of the text box 5 {6 $ ("# TextBox1 "). blur (function () // triggers 7 {8 var txt =$ (this) when the mouse clicks or leaves ). val (); // this indicates the current element, and 9} 10 var txt = $ ("# TextBox1") indicates the element written in the event of the current element ") // The CSS selector obtains the element 11 var txt =$ ("# TextBox1 "). val (); // The value of the element obtained in html is in val; the value of the element obtained in cs is in value 12 // submit the data through the hyperlink, feedback 13 // how to use Ajax to send the value of the text box 14 $. ajax ({15 url: "CheckuserName. aspx "; // The parameter 16 type:" "passed by the hyperlink; // the method in which the data is transmitted 17 data: {id: txt }, // send the user name out 18 datatype: "xml"; // the data type returned 19 success function (data) // The data here is the returned xml Information, different from the data above, the data name here can be changed to 20 {21 var co = $ (data ). find ("count "). text (); // how to obtain the returned variable 22 alert (co); // alert executes the output and obtains the value (usually used) 23 if (parseInt (c) = 0) 24 {25 $ ("Label1" ).html (); 26 var lb1 = document. getElementById ("Label1"); 27 lb1.innerHtml = ""; 28} 29 else30 {31 $ ("Label1" ).html ("this user already exists "); 32} 33} 34}) 35 36 37} 38 })

In Page_Load of Dafualt2.aspx:

In page_load:

Private DataClassesDataContext _ Context;
Protected void Page_Load (object sender, EventArgs e)
{

Connect to database
_ Context = new DataClassesDataContext ();

String uid = request ["id"]. tostring (); // verify the id
Int count = _ Context. Login. Where (r => r. username = uid). count (); // query from the database
Response. write ("<? Xml. version = '1. 0'?> "); // Return data to the page
Response. write ("<count>" + count + "</count>"); // you can customize tags in xml. html is an existing tag.
Response. close ();
XML is also a markup language used to mark content.
With <? Xml. version = '1. 0'?> It indicates that this is an XML file. Xml documents are used by default during parsing.

}