Json从JSON对象C＃获取数组对象

Question

I have this json string passed to my webapi

 string jsonstring = "{\"datamodel\": \"[{\"K1\":\"V1\",\"K2\":\"V2\"}]\"}";

I may have more than on pair of (K,V) inside. How do i parse this in C# ?

I thought i could first convert my string to a JObject and get the key for datamodel from that and then use JArray to parse the K,V. But its throwing a jsonreader exception on the first line of code here

JObject my_obj = JsonConvert.DeserializeObject<JObject>(jsonstring.ToString());

and then do this..

 JObject data = my_obj["datamodel"].Value<JObject>();

Answer 1

First of all, the JSON string you are posting is not valid. Given your comment, you can clean up the quotes before and after the square brackets using this snippet:

string jsonstring = "{\"datamodel\": \"[{\"K1\":\"V1\",\"K2\":\"V2\"}]\"}";;
string jsonstringCleaned = jsonstring.Replace("\"[", "[").Replace("]\"", "]");
var my_obj = JsonConvert.DeserializeObject<JObject>(jsonstringCleaned);

Answer 2

The code is right, but the exception you are getting is related to the formatting of your JSON string. If you put valid JSON in this code, it should work as expected.

Answer 3

JSON字符串中的V1左右缺少\\“。看起来应该像这样：

string jsonstring = "{\"datamodel\": \"[{\"K1\":\"V1\",\"K2\":\"V2\"}]\"}";

Answer 4

First always make sure that you have a valid Json string. A simple way to do that is paste it into a Json to C# converter tool, such as this one: http://json2csharp.com/

It may be simpler and more readable to use single quotes within your Json string if that is an option, as it avoids the need to escape the double quotes:

    string jsonstring = "{'datamodel': [{'K1':'V1','K2':'V2'}]}"

Now we deserialize the object and get the JArray. There is no need to call the ToString() on the JSON jsonstring string.

   var my_obj = JsonConvert.DeserializeObject<JObject>(jsonstring);
   var data = (JArray)my_obj["datamodel"];

A better and more concise way to accomplish the same result could be to just use JObject.Parse. We can accomplish the same result with just one line of code.

    var data = (JArray)JObject.Parse(jsonstring)["datamodel"];