c# - JavaScriptSerializer 反序列化为嵌套对象

Question

我有一个包含三个参数的对象(称为表达式): term1 操作 term2 其中 term1 和 term2 是对象，操作是字符串。处理对象的逻辑可以处理 term1 或 term2 作为字符串或包含嵌入表达式的递归场景。

即

[DataContract] public class expression
{
    [DataMember] public object term1 { get; set; }
    [DataMember] public string operation { get; set; }
    [DataMember] public object term2 { get; set; }
}

当我尝试反序列化 term1/term2 是简单字符串的对象时，效果很好，即

{ term1: "foo", operation: "=", term2: "bar" }

将使用 C# JavaScriptSerializer 和以下代码正确反序列化:

    public T deserialize_json<T>(string json_string)
    {
        JavaScriptSerializer serializer = new JavaScriptSerializer();
        return (T)serializer.Deserialize<T>(json_string);
    }

但是，当我尝试提交嵌套对象时，即:

{ 
  term1: 
  { 
    term1: "foo", operation: "=", term2: "bar" 
  }, 
  operation: "or", 
  term2: 
  { 
    term1: "foo", operation: "equals", term2: "baz" 
  } 
}

JavaScriptSerializer 会将 term1 和 term2 反序列化为 'System.Collections.Generic.Dictionary2[System.String,System.Object]'`

有什么想法吗？

我的方法调用很简单:

expression expr = deserialize<expression>(data);

Answer 1

您需要序列化有关 term1 和 term2 类型的信息。为此，您可以使用 Newtonsoft.Json 库。

试试这个代码:

expression model = new expression() { term1 = new expression() { operation = " + " } };
string content = ModelManager<expression>.SaveToString(model);
/* content =
{
    "$type": "Test.expression, Test",
    "term1": {
    "$type": "Test.expression, Test",
    "operation": " + "
    }
}
*/
var model2 = ModelManager<expression>.LoadFromString(content);
string content2 = ModelManager<expression>.SaveToString(model2);
// content == content2 

public static class ModelManager<T>
{
    public static T LoadFromString(string content)
    {    
        using (var sr = new StringReader(content))
        using (var jr = new JsonTextReader(sr))
            return GetSerializer().Deserialize<T>(jr);
    }
    public static string SaveToString(T model)
    {
        StringBuilder sb = new StringBuilder(512);

        using (var sw = new StringWriter(sb, System.Globalization.CultureInfo.InvariantCulture))
        using (var jtw = new JsonTextWriter(sw))
            GetSerializer().Serialize(jtw, model);

        return sb.ToString();
    }

    private static Newtonsoft.Json.JsonSerializer GetSerializer()
    {
        return new Newtonsoft.Json.JsonSerializer()
        {
            NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore,
            DefaultValueHandling = Newtonsoft.Json.DefaultValueHandling.Include,
            TypeNameHandling = Newtonsoft.Json.TypeNameHandling.Objects,
            TypeNameAssemblyFormat = System.Runtime.Serialization.Formatters.FormatterAssemblyStyle.Simple,
            Formatting = Formatting.Indented,
            MaxDepth = null,
            ReferenceLoopHandling = ReferenceLoopHandling.Error,
            PreserveReferencesHandling = PreserveReferencesHandling.None
        };
    }
}