Question

我在这里做错了什么？

using System.Web.Script.Serialization;

string json = "{\"numbers\":[{\"one\":\"1\"},{\"two\":\"2\"},{\"three\":\"3\"}]}";
dynamic dictionary = new JavaScriptSerializer().Deserialize<dynamic>(json);
Assert.AreEqual(3, dictionary["numbers"].Count);

System.NullReferenceException : Object reference not set to an instance of an object
  at System.Web.Script.Serialization.JavaScriptSerializer.ConvertToObject (IDictionary`2 dict, System.Type type) [0x00000] in <filename unknown>:0 
  at System.Web.Script.Serialization.JavaScriptSerializer.ConvertToType (System.Type type, System.Object obj) [0x00000] in <filename unknown>:0 
  at System.Web.Script.Serialization.JavaScriptSerializer.ConvertToList (System.Collections.ArrayList col, System.Type type) [0x00000] in <filename unknown>:0 
  at System.Web.Script.Serialization.JavaScriptSerializer.ConvertToType (System.Type type, System.Object obj) [0x00000] in <filename unknown>:0 
  at System.Web.Script.Serialization.JavaScriptSerializer.ConvertToObject (IDictionary`2 dict, System.Type type) [0x00000] in <filename unknown>:0 
  at System.Web.Script.Serialization.JavaScriptSerializer.ConvertToType (System.Type type, System.Object obj) [0x00000] in <filename unknown>:0 
  at System.Web.Script.Serialization.JavaScriptSerializer.ConvertToType[Object] (System.Object obj) [0x00000] in <filename unknown>:0 
  at System.Web.Script.Serialization.JavaScriptSerializer.Deserialize[Object] (System.String input) [0x00000] in <filename unknown>:0

Answer 1

我认为你的代码没有问题，除了使用count属性，并且由于代码在json被反序列化时破坏了，我建议你使用静态类型定义，只是为了缩小代码问题的变化：

        string json = "{\"numbers\":[{\"one\":\"1\"},{\"two\":\"2\"},{\"three\":\"3\"}]}";
        var dictionary = new JavaScriptSerializer().Deserialize<Dictionary<string, object>>(json);

也许只是在JavaScriptSerializer中使用动态类型时可能存在问题，如果JavaScriptSerializer确实存在问题，您可以随时向MSFT报告。

Answer 2

由于我无法使Dictionary<string, object>工作，我决定放弃它并使用静态类型。 BTW，this online tool对于从JSON生成C＃类非常方便。

JavaScriptSerializer：未将对象引用设置为对象的实例

2 个答案: