JavaScript gets background C # variables and back-end methods

Sometimes you need to get the value of the background variable in JavaScript to determine the JavaScript execution logic, or you need to call the C # backend method to get the data , we can use <%=% The > expression is easily implemented, and <%=%> mainly binds the expression and evaluates the value of the expression.

1.JavaScript gets the background variable. Declare a global variable in the background and set the Access property of the variable to protected or public, which you can use on the page.

Declare a variable of type protected or public in the background C # code:

1 public partial class WebForm1:System.Web.UI.Page

2 {

3 protected string str;

4 protected void Page_Load (object sender, EventArgs e)

5 {

6 str = "Hello";

7}

8}<br>

Gets the value of the variable in the foreground JS:

1 <script type= "Text/javascript" >

2 $ (document). Ready (function () {

3 Alert ("<%=str%>");

4});

5 </Script>

2. Call the background method in JavaScript. To declare a public type method in the background , the Access property of the method must be public so that it can be accessed at the foreground.

A method that declares a pubic type in the background :

public partial class WebForm1:System.Web.UI.Page

02 {

protected void Page_Load (object sender, EventArgs e)

04 {

05

06}

public string Getstr ()

08 {

Return "Hello World";

10}

11}

Call the background C # method in the foreground JS to get the value:

1 <script type= "Text/javascript" >

2 $ (document). Ready (function () {

3 Alert ("<%=getstr ()%>");

4});

5 </Script>

JavaScript gets background C # variables and back-end methods