JSON反序列化C＃错误

Question

I'm following this JSON deserialization example: Deserialize JSON with C#

but I've run into a problem. My json file has a different structure.

"data": [
  {
     "id": "157156474316544_575441765821344",
     "from": {
        "name": "Testy McTest",
        "id": "624161969"
     },
     "message": "I am a message"...

So when I instantiate the serializer:

FacebookFeed facebookPosts = new JavaScriptSerializer().Deserialize<FacebookFeed>(jsonFromWeb);

I get the error "No parameterless constructor defined for type of 'System.String'."

If anybody know how to fix this I would greatly appreciate it.

My structure is :

public class FacebookFeed
{
public List<FacebookPost> data { get; set; }
}

public class FacebookPost 
{
public string id        { get; set; }
public string from      { get; set; }
public string message   { get; set; }
}

Answer 1

The problem is that from is an complex(it has several user attributes/properties - id, name) object but you've declared it as plain string. Try something like:

public class Sender
{
public string id {get;set;}
public string name {get;set;}
}

public class FacebookPost 
{
public string id        { get; set; }
public Sender from      { get; set; }
public string message   { get; set; }
}

Answer 2

'from' is an object, not a string. Thus you are getting the error "No parameterless constructor defined for type of 'System.String'."