Invoking the background C # function in JavaScript using AJAX

Invoking the background C # function in JavaScript using AJAX

Recently in a project that follows a website, the username requirement of the user table in the database is unique, so when the user chooses a user name to register, first check whether the user name is occupied and give a hint. The initial implementation is: After the user fills out the registration form submits, validates in the background. But see a lot of Web site design is when users fill out the user name, the textbox loses focus will immediately give hints, such as https://passport.csdn.net/account/register, reaction is very fast, should be in the foreground to check. It took some time today to look up some information on this point.

JS calls the background C # function to detect the user name and need to get the user name entered by the user, and then check if the database already contains the user name:

The method of passing parameters, some (http://www.cnblogs.com/morningwang/archive/2008/04/07/1140340.html) uses the following method:

Background

Protected string Csharpvoid (String STRCC)
{
STRCC = "Hello!" "+ STRCC;
return STRCC;
}

Front desk

function Init ()
{
var v = "China";
var s = ' <%=csharpvoid ' ("' +v+ '")%> ';
alert (s);
}

I tried, and the results were not as good as I wanted. Finally, we decided to use Ajax to implement it. As a result of very little understanding, so the whole process also took a lot of detours, fortunately, the last is to get out. The specific implementation steps are as follows:

Add Reference under 1.bin directory: Ajaxpro.2.dll

And in the background codefile and add using Ajaxpro;

2.web.config <add name= "Ajaxpro" verb= "Post,get" path= "Ajaxpro/*.ashx" type= "ajaxpro.ajaxhandlerfactory,ajaxpro.2"/>

3.site.master in the aspx file <asp:ScriptManager> added, enablepagemethods= "true".

4. How to use:

1) Add before class: [Ajaxnamespace ("ANSP")] (modify namespace name, can skip)

[Ajaxnamespace ("ANSP")]
public partial class Physician_WUC_PhysicianInfor:System.Web.UI.UserControl
{

}

2) Page_Load

protected void Page_Load (object sender, EventArgs e)
{
Lca_dataservice = new Lca_database_service.lca_database_service ();
Utility.registertypeforajax (typeof (Physician_wuc_physicianinfor));
}

3) to invoke the method before adding: [Ajaxpro.ajaxmethod]

[Ajaxpro.ajaxmethod]
public bool Checkusernameexist (string username)
{
BOOL Notexist = false;

Try
{
System.Data.DataSet ds = Lca_dataservice.readdoctor (username);
if (ds = = null | | ds. Tables[0]. Rows.Count <= 0)
{
Notexist = true;
}
}
catch (Exception ex)
{
Notexist = false;
}
return notexist;
}

4) Front-Office JS call method:

var Exist = ANSP. Checkusernameexist (userName). value;

exist returns a value for the function.

if (exist==true)
{

User name does not exist

}else

{

User name exists

}

After the above setup, it is achieved the desired requirements.

Invoking the background C # function in JavaScript using AJAX