Ajax中传递Json格式的参数

https://www.cnblogs.com/esther-qing/p/5944724.html

$.ajax({
    type: "post",
    url: baseUrl+"sys/login",
    dataType: "json",
    contentType: "application/json;charset=utf-8",
    data: JSON.stringify({userName: loginapp.userName,userPassword: loginapp.userPassword}),
　　
  或者拼接字符串的形式：
    data: "{'userName': '"+loginapp.userName+"','userPassword': '"+loginapp.userPassword+"'}",