解决方案：
var jsonData = { "id": "123"};
$.ajax({
type: "post",url: '/Table/GridData',data:jsonData,async: false,dataType: "html",success: function (msg) { // Do something interesting here.
alert(msg.d);
}
});
注意的几个地方：
1、dataType一定是“html”，不能是“json”
2、不能包含contentType: "application/json; charset=utf-8"
