如何使用从POST请求发送到C＃的JSON？

Question

正如标题所说，我希望在C＃后端操作从客户端AJAX POST请求接收的JSON。这是我的代码：

客户端：

var myData = { Name: "tyler", Age: 3 };
var moreData = {
    documentName: "Doc-109",
    attachments: {
        name: "Attachment 11"
    }
};
$.post('/NMISProduct/Index', { myData: myData, moreData: moreData }, function(returnedData) {
    console.log(returnedData);
}, 'json');

C＃后端：

[HttpPost]
public ActionResult Index(string myData, string moreData)
{
    //I want to return myData.Name + moreData.attachments.name in JSON format - How do I do this?
}

我该怎么做？