$.ajax data向后台传递参数失败 contentType: "application/json"

在ajax方法设置中若不添加 contentType: "application/json" 则data可以是对象：

$.ajax({
url: actionurl,
type: "POST",
datType: "JSON",
data: { id: nodeId },
async: false,
success: function () {}
});

若添加 contentType: "application/json" 则data只能是json字符串：

$.ajax({
url: actionurl,
type: "POST",
datType: "JSON",
contentType: "application/json"
data: "{'id': " + nodeId +"}",
async: false,
success: function () {}
});

不添加 contentType: "application/json" 情况下传递多个数据：

{
"id":id[1],
"name":"小明"
}

此时将id和name传到后台。