Jquery WebService请求格式无效
WebSercie中代码

C# code

[WebMethod]
        public ArrayList HelloWorld()
        {
            ArrayList al = new ArrayList(200);
            for (int i = 0; i < 10; i++)
            {
                 ArrayList alItem = new ArrayList();
                    alItem.Add(i);
                    alItem.Add(i+"ab");
                    al.Add(alItem);
            }
            return al;
        }

JS代码

JScript code

$.ajax({
        type: "POST",
        contentType: "application/json; charset=utf-8",
        url: "/WebService/ProductGroupService.asmx/HelloWorld",
        data: "{}",
        success: function(data) {
            alert("Success");
        },
        error: function(err) {
            alert(err.responseText);
        }
    });

这个该怎么改 
提示请求格式无效：application/json; charset=utf-8 
在线等

------解决方案--------------------
public ArrayList HelloWorld()
{
ArrayList al = new ArrayList(200);
for (int i = 0; i < 10; i++)
{
ArrayList alItem = new ArrayList();
alItem.Add(i);
alItem.Add(i+"ab");
al.Add(alItem);
}
//return al;
Response.Write("{\"key1\":\"value\",\"key2\":\"value\"}");
}




这个是最简单的json的格式，楼主试试，前台能获取 data 吗

$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
url: "/WebService/ProductGroupService.asmx/HelloWorld",
data: "{}",
success: function(data) {
alert(data);
},
error: function(err) {
alert(err.responseText);
}
});



------解决方案--------------------
ArrayList是后台的变量类型,返回到前台,js又不能识别
需要返回js能识别的变量类型
------解决方案--------------------
返回的格式不对