包含值为dataTable的字典的Json.net反序列化字典

Question

我是编程新手(在课堂环境之外)。

我正在开发一个有插件的应用程序。每个插件打包/解包它的状态(作为字典)，并将其自身发送到包含所有打包状态的字典中。我使用Json.Net来序列化/反序列化每个插件，并将每个插件传递给它自己的类进行打包/解包，这取决于项目是被保存还是被打开。

我遇到的问题是，当我的第一个插件将其打包状态的字典版本解包时，我开始重新填充每个属性，第一个属性(字典中的第一项)是一个DataTable。我收到一个错误，说：

Unable to cast object of type 'Newtonsoft.Json.Linq.JArray' to 
type 'System.Data.DataTable'.

下面是我的序列化代码。

IDictionary<string, IDictionary<string, object>> pluginStates = 
             new Dictionary<string, IDictionary<string, object>>();
signaller.RaiseSaveRequest(pluginStates); //gets all of the plugins' packedState

JsonSerializer serializer = new JsonSerializer();
serializer.ObjectCreationHandling = ObjectCreationHandling.Replace; 
serializer.TypeNameHandling = TypeNameHandling.All; 

using (StreamWriter sw = new StreamWriter(strPathName))
using (JsonWriter writer = new JsonTextWriter(sw))
{
    serializer.Serialize(writer, pluginStates);
}

和反序列化。

 IDictionary<string, IDictionary<string, object>> pluginStates = 
           new Dictionary<string, IDictionary<string, object>>();

 JsonSerializer serializer = new JsonSerializer();
 serializer.ObjectCreationHandling = ObjectCreationHandling.Replace; 
 serializer.TypeNameHandling = TypeNameHandling.All; 

 StreamReader sr = new StreamReader(fullName);
 JsonTextReader reader = new JsonTextReader(sr);
 string json = sr.ReadToEnd();
 pluginStates = serializer.Deserialize<IDictionary<string, IDictionary<string, Object>>>(reader);
 pluginStates = JsonConvert.DeserializeObject<IDictionary<string, IDictionary<string, Object>>>(json);
 sr.Close();
 reader.Close();

 signaller.UnpackProjectState(pluginStates);

我试着查看了NewtonSoft.Json上的文档，但我几乎不理解它以及如何在我的代码中使其工作。我在想，一旦插件的打包状态需要解包，我就需要对Converter或解析做一些处理。打包后，插件的第一个字典条目被保存为DataTable。然后，在解包时，它是带有:分隔符的值中的实际dataTable。

我会提供屏幕截图，但我还没有想好怎么做。你知道我错过了什么吗？谢谢!

Answer 1

保存项目时，ProjMngr将获取打包的pluginStates字典。我循环遍历pluginStates字典中的每个字典(插件)，并创建一个包含键、值( json字符串版本)和键、值(.net类型)的字典。将这些元素添加到一个数组中，并将该数组放入序列化的最终projectState字典中。这是代码。

signaller.RaiseSaveRequest(pluginStates);  <----has all plugin's packedState

//loop through plugins to get values and types
Dictionary<string, object> dictProjectState = new Dictionary<string, object>();

foreach (KeyValuePair<string,IDictionary<string,object>> plugin in pluginStates)
{ 
    //holds jsonRepresented values
    Dictionary<string, object> dictJsonRep = new Dictionary<string, object>(); 
    //holds object types
    Dictionary<string, object> dictObjRep = new Dictionary<string, object>(); 
    object[] arrayDictHolder = new object[2];  //holds all of the dictionaries

    string pluginKey = plugin.Key;

    IDictionary<string, object> pluginValue = new Dictionary<string, object>(); 
    pluginValue = plugin.Value;

    foreach (KeyValuePair<string, object> element in pluginValue)
    {
      string jsonRepresentation = JsonConvert.SerializeObject(element.Value);
      object objType = element.Value.GetType();
      dictJsonRep.Add(element.Key, jsonRepresentation);
      dictObjRep.Add(element.Key, objType);
    }
    arrayDictHolder[0] = dictJsonRep;
    arrayDictHolder[1] = dictObjRep;
    dictProjectState.Add(pluginKey, arrayDictHolder);
}

JsonSerializer serializer = new JsonSerializer();

using (StreamWriter sw = new StreamWriter(strPathName))
using (JsonWriter writer = new JsonTextWriter(sw))
{
    serializer.Serialize(writer, dictProjectState);
}

然后，当一个项目打开时，我反过来做了同样的事情，让pluginState回到它的原始状态，发送给每个插件。在发送前使用了类型以确保类型正确。我意识到我必须反序列化几次，这是令人惊讶的。我就是离不开Jarray或Jobject。但这是可行的。这就是我的开场白。

IDictionary<string, IDictionary<string, object>> pluginStates = new Dictionary<string, IDictionary<string, object>>();

StreamReader sr = new StreamReader(fullName);
JsonTextReader reader = new JsonTextReader(sr);
string json = sr.ReadToEnd();

var dictProjectState = JsonConvert.DeserializeObject<Dictionary<string, object>>(json);
sr.Close();
reader.Close();

foreach (var projectStatePair in dictProjectState)
{
    string pluginKey = projectStatePair.Key; //key in pluginStates dict
    Dictionary<string, object> dictJsonRep = new Dictionary<string, object>();
    Dictionary<string, object> dictObjRep = new Dictionary<string, object>();
    Dictionary<string, object> pluginValues = new Dictionary<string, object>();

    string stpluginValue = projectStatePair.Value.ToString();

    Newtonsoft.Json.Linq.JArray ja = (Newtonsoft.Json.Linq.JArray)JsonConvert.DeserializeObject(stpluginValue);

    object[] arrayHolder = ja.ToObject<object[]>();

    string strArray0 = arrayHolder[0].ToString();
    string strArray1 = arrayHolder[1].ToString();

    dictJsonRep = JsonConvert.DeserializeObject<Dictionary<string, object>>(strArray0);
    dictObjRep = JsonConvert.DeserializeObject<Dictionary<string, object>>(strArray1);

    foreach (var pair in dictJsonRep)
    {
         string strVariableKey = pair.Key;
         object objType = dictObjRep[pair.Key];
         string jsonRep = (string)pair.Value;
         Type jsonType = Type.GetType(objType as string);
         object jsonReprValue = null;
         jsonReprValue = JsonConvert.DeserializeObject(jsonRep, jsonType);
         pluginValues.Add(strVariableKey, jsonReprValue);
    }
    pluginStates.Add(pluginKey, pluginValues);
}

signaller.UnpackProjectState(pluginStates);

希望这能帮助任何寻找答案的人。