Prevents users from clicking the submit button to process code multiple times before the server completes processing.

If the webpage speed is too slow or the user submits multiple times, the data may be modified. How can this problem be solved?
This section is placed in Page_Load.
Copy codeThe Code is as follows:
If (! Page. IsPostBack)
{
System. Text. StringBuilder s = new System. Text. StringBuilder ();
S. Append ("();");
S. Append (this. GetPostBackEventReference (this. Button1 ));
This. Button1.Attributes. Add ("onclick", s. ToString ());
}
A () is JS
Function ()
{
Var OK = document. getElementById ('button1 ');
OK. disabled = true;
Return true;
}

After concentration:
Copy codeThe Code is as follows:
BtnSave. Attributes. Add ("onclick", "this. disabled = 'true';" + GetPostBackEventReference (btnSave ));

A problem was slightly plagued, and then solved, btnSave. attributes. add ("onclick", "a ();" + GetPostBackEventReference (btnSave); If a () contains other verifications, such as some regular expressions, btnSave. attributes. add ("onclick", "return a ();" + GetPostBackEventReference (btnSave. You can write all JS code in the CS file and then pull it.
Copy codeThe Code is as follows:
System. Text. StringBuilder s = new System. Text. StringBuilder (); s. Append ("var OK = document. getElementById ('button1 ');");
S. Append ("OK. disabled = true ;");
S. Append (this. GetPostBackEventReference (this. Button1 ));
This. Button1.Attributes. Add ("onclick", s. ToString ());
//. Net 2.0 or above
Button1.Attributes. Add ("onclick", "this. disabled = true;" + this. ClientScript. GetPostBackEventReference (Button1 ,""));

Or:
Copy codeThe Code is as follows:
<Asp: Button ID = "btnSumbit" runat = "server" UseSubmitBehavior = "false" OnClientClick = "this. value = 'sumbit '; this. disabled = true; "Text =" Sumbit "OnClick =" btnSumbit_Click "/>

Other methods (available for trial)
Method 1:
Copy codeThe Code is as follows:
Protected void Page_Load (object sender, EventArgs e)
{
Btn. Attributes. Add ("onclick", "state = true ;");
StringBuilder sb = new StringBuilder ();
Sb. Append ("if (! State) return ;");
Sb. Append ("var button = document. getElementByIdx_x ('btn ');");
Sb. Append ("button. value = 'Please Wait ...';");
Sb. Append ("document. body. style. cursor = 'wait ';");
Sb. Append ("button. disabled = true ;");
String strScript = "<script> ";
StrScript = strScript + "var state = false ;";
// Bind the function to the onbeforeunload event on the page:
StrScript = strScript + "window. attachEvent ('onbeforeunload', function () {" + sb. ToString () + "});";
StrScript = strScript + "</" + "script> ";
Page. RegisterStartupScript ("onbeforeunload", strScript );
}
Protected void Submit_Click (object sender, EventArgs e)
{
// Simulate button processing for a long time
System. Threading. Thread. Sleep (2000 );
Response. Write ("<script> alert ('bbbbbb !! '); "+" </"+" Script> ");
}
<Asp: Button ID = "btn" Text = "Submit" OnClick = "Submit_Click"
Runat = "server"/>

Method 2:
Copy codeThe Code is as follows:
<Asp: button id = "btnSubmit" OnClick = "Submit_Click" runat = "server" OnClientClick = "this. disabled = true; this. form. submit (); "UseSubmitBehavior =" False "/>

Method 3:
Copy codeThe Code is as follows:
This. btnSubmit. Attributes ["onclick"] = this. GetPostBackEventReference (this. btnSubmit) + "; this. disabled = true;"; // prevents repeated submissions