JQuery Ajax error when call server side method in asp C#

Question

I'm trying to call server side method using ajax in asp C# application.

i have the following code in aspx file

function editApp(appID) {     
            $.ajax({
            type: "POST",
            url: "Default.aspx/GetSquare",
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            data: "{}",
            success: function (data) {
                alert(data);
            },

            error: function () {
                alert("Ajax Error"); 
            }
        });
}

and the following code in aspx.cs file

[WebMethod]
    public static string GetSquare()
    {
        return "OK";
    }

but in each time i call editApp function i get the following alert "Ajax Error"

Answer 1

Since you are not passing any parameters, mentioning as data: "{}" is giving you errors. Instead you have to specify as data: {} as shown below.

function editApp(appID) {     
            $.ajax({
            type: "POST",
            url: "Default.aspx/GetSquare",
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            data: {},
            success: function (data) {
                alert(data);
            },

            error: function () {
                alert("Ajax Error"); 
            }
        });
}