C # interaction with Java Functions

C # interaction with Java Functions
1. Call the method of jacascript at the front end in the C # code of the background:

Method 1: add the Java function to the Click Event of the button in the page_load event.

HTML code:

<SCRIPT type = "text/JavaScript" Language = "JavaScript">
Function jstest ()
{
Alert ("this is the js method ");
Return false;
}
</SCRIPT>
1. <asp: button id = "button1" runat = "server" text = "button"/> // Javascript is implemented. The onclientclick/onclick attribute can be added or not.
2. <asp: button id = "button1" runat = "server" text = "button" onclick = "button#click"/> // onclick is added, the JS function is executed together with the onclick method in the background.

. CS code:

Protected void page_load (Object sender, eventargs E)
{
Button1.attributes ["onclick"] = "Return jstest ();"; // jstest () is a JS function.
}
Method 2: Call it directly in the click event. HTML code:

<SCRIPT type = "text/JavaScript" Language = "JavaScript">
Function jstest ()
{
Alert ("this is the js method ");
Return false;
}
</SCRIPT>
<Asp: button id = "button1" runat = "server" text = "button" onclick = "button#click"/>
. CS code:

Protected void button#click (Object sender, eventargs E)
{
Clientscript. registerstartupscript (this. GetType (), "clear", "<SCRIPT> jstest () </SCRIPT> ");
}
2. Javascript calls the C # method in the front-end html

1). the CS background C # method has a return value. The Code is as follows:

 

Protected string csharpmethod1 (string STRC) // a parameter exists.
{
String text = STRC;
Textbox1.text = text;
Return STRC;
}
Protected string csharpmethod2 () // no difference
{
Textbox1.text = button1.text;
Return textbox1.text. tostring ();
}
HTML code:

 

<Script language = "JavaScript">
Function jstest1 ()
{
VaR S = "<% = csharpvoid (" parameter method available ") %> ";
// Return S;
Document. Write (s );
}
Function jstest2 ()
{
VaR S = "<% = csharpvoid () %> ";
Return S;
}
</SCRIPT>

<Asp: textbox id = "textbox1" runat = "server"> </ASP: textbox>
<Asp: button id = "button1" runat = "server" text = "button" onclientclick = "jstest1 ()"/>
<Asp: button id = "button1" runat = "server" text = "button" onclientclick = "jstest2 ()"/>
2) C # No return value for the method,. CS code:

Public void csharpvoid ()
{
String text = button1.text;
Textbox1.text = text;
}
HTML code:

<Script language = "JavaScript">
Document. Write ("<% csharpvoid (); %> ");
</SCRIPT>
Another method is to write the event content to the Click Event of a control, and hide the control settings. In this way, only the background method is available and JavaScript is used to call the control. As shown below, there is a button button1 event.

. CS code:

Protected void button#click (Object sender, eventargs E)
{
Textbox1.text = "JS call button method ";
}
Then, JavaScript Functions are called using the client events of button2 in HTML. The code is:

 

<Script language = "JavaScript">
Function jstest3 ()
{
Document. getelementbyid ("button1"). Click ();
}
</SCRIPT>
<Asp: textbox id = "textbox1" runat = "server"> </ASP: textbox>
<Asp: button id = "button1" runat = "server" text = "button" style = "display: none;" onclick = "button#click"/>
<Asp: button id = "button2" runat = "server" text = "button" onclientclick = "jstest3 ()"/>
3. Access the C # variable in Javascript

Define a variable in. CS code

Public String n = "C # variable ";
At the front-end, use Java to call and output this variable.

<Script language = "JavaScript">
Function getcsharp ()
{
VaR S = "<% = n %>"; // n is the background variable.
Document. Write (s );
}
</SCRIPT>
<Asp: button id = "button1" runat = "server" text = "button" onclientclick = "getcsharp ()"/>
4. Call Java variables in C #

Method 1: 1. the foreground uses static text controls to hide the field and write the JS variable value into it. 2. The background uses request ["ID"] to obtain the value;
Method 2: cookie or session can be used

 

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