我如何用TypeNameHandling反序列化.Json中的对象.净Silverlight

Question

当我试图在Silverlight中反序列化时，我得到了一个异常。Test1失败，Test2成功。我也尝试过TypeNameAssemblyFormat简单和完整，但得到相同的结果。Test2可以解析程序集，为什么Json.NET不能?

Update:忘了提到我试图反序列化的类型是在与反序列化发生的silverlight程序集不同的程序集中定义的。

两个测试都可以在非silverlight . net应用程序中运行。

我如何反序列化一个json字符串有typennames ?

private void Test1()
{
    JsonSerializerSettings settings = new JsonSerializerSettings();
    settings.TypeNameHandling = TypeNameHandling.Objects;
    string json1 = "{"$type":"AmberGIS.NetworkTrace.DTO.NTPoint, NetworkTrace.DTO.Assembly","X":0.0,"Y":0.0,"SpatialReference":null}";
    try
    {
        var n1 = JsonConvert.DeserializeObject<NTPoint>(json1, settings);
        //Error resolving type specified in JSON 'AmberGIS.NetworkTrace.DTO.NTPoint, NetworkTrace.DTO.Assembly'.
        //Could not load file or assembly 'NetworkTrace.DTO.Assembly, Culture=neutral, PublicKeyToken=null' or one of its dependencies. 
        //The requested assembly version conflicts with what is already bound in the app domain or specified in the manifest. 
        //(Exception from HRESULT: 0x80131053)
    }
    catch (Exception ex)
    {
        while (ex != null)
        {
            Debug.WriteLine(ex.Message);
            ex = ex.InnerException;
        }
    }
}

这个Test2成功:

private void Test2()
{
    var pnt1 = new AmberGIS.NetworkTrace.DTO.NTPoint();
    Debug.WriteLine(pnt1.GetType().AssemblyQualifiedName);
    // "AmberGIS.NetworkTrace.DTO.NTPoint, NetworkTrace.DTO.Assembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"
    string fullName = "AmberGIS.NetworkTrace.DTO.NTPoint, NetworkTrace.DTO.Assembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null";
    var t = Type.GetType(fullName);
    var pnt2 = Activator.CreateInstance(t) as NTPoint;
}

Answer 1

尝试为JsonConvert.DeserializeObject<T>(json, Settings)添加设置，其中Settings为:

new JsonSerializerSettings
                {
                    TypeNameHandling = TypeNameHandling.Objects,
                    TypeNameAssemblyFormat = System.Runtime.Serialization.Formatters.FormatterAssemblyStyle.Full
                }

Answer 2

我通过下载Json源代码解决了我的问题。. NET 4.0r2，并向DefaultSerializationBinder.cs添加2行hack代码，如下所示。这可能不适用于强命名程序集。Silverlight缺少一种方法来扫描appdomain中加载的程序集，见这里。

#if !SILVERLIGHT && !PocketPC
        // look, I don't like using obsolete methods as much as you do but this is the only way
        // Assembly.Load won't check the GAC for a partial name
#pragma warning disable 618,612
        assembly = Assembly.LoadWithPartialName(assemblyName);
#pragma warning restore 618,612
#else
          // **next 2 lines are my hack** ...
          string fullName = String.Format("{0}, {1}, Version=1.0.0.0,  Culture=neutral, PublicKeyToken=null",typeName,assemblyName);
          return Type.GetType(fullName);
        assembly = Assembly.Load(assemblyName);
#endif

Answer 3

我在这里张贴我的解决方案，不需要修改Json。净:

问题是以下行对于Silverlight来说是不够的:

string json1 = "{"$type":"AmberGIS.NetworkTrace.DTO.NTPoint, NetworkTrace.DTO.Assembly" ... }";

需要

:

string json1 = "{"$type":"AmberGIS.NetworkTrace.DTO.NTPoint, NetworkTrace.DTO.Assembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null ", ...}";

所以我的方式包括JSON(在我的情况下JSON不能改变，因为它来自服务器，不是由JSON.net生成)是手动修改JSON通过迭代所有(嵌套)对象和插入汇编信息:

string json = <some json you want fixed>
Type type = <the target type you want>
JObject jsonObject = JObject.parse (json);
jsonObject["$type"] = type.FullName + ", " + type.Assembly.FullName;
json = jsonObject.ToString(Formatting.None, null);

然后可以像往常一样使用

反序列化

JsonSerializerSettings settings = new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.All };
var n1 = JsonConvert.DeserializeObject<NTPoint>(json, settings);