Summary of js call background, background call foreground and other methods, js front-end

Summary of js call background, background call foreground and other methods, js front-end
1. Execute functions in C # code in javaScript Functions:

Method 1: 1. Create a button to write the called or processed content to button_click in the background;

2. Write a js function on the front-end with the content document. getElementByIdx ("btn1"). click ();

3. Call js functions on the frontend or backend to stimulate the click event, which is equivalent to accessing the c # function in the background;

Method 2: 1. function declaration is public

Background code (change public to protected)

Public string ss ()

{

Return ("");

}

2. You can call <% = fucntion () %> in html.

Foreground script

<Script language = javascript>

Var a = "<% = ss () %> ";

Alert ();

</Script>

Method 3: 1. <script language = "javascript">

<! --

Function _ doPostBack (eventTarget, eventArgument)

{

Var theForm = document. Form1; // indicates the form of runat = server.

TheForm. _ EVENTTARGET. value = eventTarget;

TheFrom. _ EVENTARGUMENT. value = eventArgument;

TheForm. submit ();

}

-->

</Script>

<Input type = "button" value = "button">



Method 4: <script language = "javascript">

Function SubmitKeyClick ()

{

If (event. keyCode = 13)

{

Event. cancelBubble = true;

Event. returnValue = false;

Document. all. FunName. value = "Name of the function you want to call ";

Document. form [0]. submit ();

}

}

</Script>

<INPUT type = "text">

<Input type = "hidden"> <〈! -- Used to store the function you want to call --> --〉

In. CS, there are:

Public Page_OnLoad ()

{

If (! Page. IsPost ())

{

String strFunName = Request. Form ["FunName"]! = Null? Request. Form ["FunName"]: "";

// Determine which function to call based on the value returned

Switch (strFunName)

{

Case "enter ()":

Enter (); // call this function

Break;

Case "Others ":

// Call other functions

Break;

Default:

// Call the default Function

Break;

}

}

}

Public void enter ()

{

//...... For example, calculating a value

}

2. How to access the C # variable in JavaScript?

The answer is as follows:

Method 1: 1. Access the <input type = "hidden" runat = "server">

Method 2: 1. For example, public string n is defined in the background; the format of the variable referenced in front-end js is '<% = n %>' or "+ <% = n %> +"

Method 3: 1. You can register a script on the page after assigning values to variables on the server.

"<Script language = 'javascript '> var temp =" + tmp + "</script>"

Tmp is the background variable, and then you can directly access temp in js to obtain the value.

3. How to access existing JavaScript variables in C?

The answer is as follows:

Method 1: 1. the foreground uses static text controls to hide the field and write the js variable value into it;

2. the backend uses request ["id"] to obtain the value;

Method 2: cookie or session can be used

4. How to access JavaScript Functions in C?

The answer is as follows:

C # execute javaScript Functions in the Code:

Method 1: 1. Page. RegisterStartupScript ("ggg", "<script> SetVisible (1); </script> ");

Method 2: Use the Literal class and

Private void Button2_Click (object sender, System. EventArgs e)

{

String str;

Str = "<script language = 'javascript '> ";

Str + = "selectRange ()";

Str + = "</script> ";

// Literal1.Visible = true;

Literal1.Text = str;


}

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