.net 使用$.ajax实现从前台调用后台方法(包含静态方法和非静态方法调用)

/*---------------后台必须是静态方法-------------*/
/*---------------前台*-----------------/
$(function() {     
    $("#btnOK").click(function() {     
        $.ajax({     
            type: "Post",     
            url: "demo.aspx/GetStr",     
            //方法传参的写法一定要对，str为形参的名字,str2为第二个形参的名字      
            data: "{'str':'I am','str2':'XXX'}",     
            contentType: "application/json; charset=utf-8",     
            dataType: "json",     
            success: function(data) {     
                //return data      
                  alert(data.d);     
            },     
            error: function(err) {     
                alert(err);     
            }     
        });     

        //禁用按钮的提交      
        return false;     
    });     
});    

/*---------------前台*-----------------/

/*---------------后台*-----------------/

[WebMethod]     
public static string GetStr(string str, string str2)     
{     
    return str + str2;     
} 

/*---------------后台*-----------------/

/*---------------后台必须是静态方法-------------*/
/*---------------后台可以是非静态方法-----------*/
/*---------------前台-------------------------*/

$.ajax({
type: "POST",
url: "McuHandler.ashx",
data: { page: 'ActivityEnrolment.aspx', method: 'GetActivityItemById', val: coaInfo },
success: function (msg) {
if ($("#TravelInsuranceValueLabelForInsert")[0] != undefined) {
$("#TravelInsuranceValueLabelForInsert")[0].innerText = msg;
}
if ($("#TravelInsuranceValueLabelForEdit")[0] != undefined){
$("#TravelInsuranceValueLabelForEdit")[0].innerText = msg;
}
}
});

/*---------------前台-------------------------*/

/*---------------后台-------------------------*/
1.新增一个ashx文件
2.在ProcessRequest方法中调用非静态方法并返回值

public void ProcessRequest(HttpContext context)
{
var val = context.Request.Form["val"];//GET方式提交就用context.Request.QueryString["val"]
var page = context.Request.Form["page"];
var method = context.Request.Form["method"];
var rtnVal = string.Empty;
context.Response.ContentType = "text/plain";
switch (page)
{
case "ActivityEnrolment.aspx":
switch (method)
{
case "GetActivityItemById":
rtnVal = GetActivityItemById(val);
context.Response.Write(rtnVal.ToFormatDecimalText(DecimalPlace.Two, true));
break;
default:
context.Response.Write("");
break;
}
break;
default:
context.Response.Write("");
break;
}

/*---------------后台-------------------------*/

/*---------------后台可以是非静态方法-----------*/