json.net在序列化时限制maxdepth

我无法想到用Json.NET开箱即用的方法,因为(正如你正确观察到的) MaxDepth在序列化时会被忽略.您可以做的是继承 JsonTextWriter并自己进行检查：

public class MaxDepthJsontextWriter : JsontextWriter
{
    public int? MaxDepth { get; set; }
    public int MaxObservedDepth { get; private set; }

    public MaxDepthJsontextWriter(TextWriter writer,JsonserializerSetTings setTings)
        : base(writer)
    {
        this.MaxDepth = (setTings == null ? null : setTings.MaxDepth);
        this.MaxObservedDepth = 0;
    }

    public MaxDepthJsontextWriter(TextWriter writer,int? maxDepth)
        : base(writer)
    {
        this.MaxDepth = maxDepth;
    }

    public override void WriteStartArray()
    {
        base.WriteStartArray();
        checkDepth();
    }

    public override void WriteStartConstructor(String Name)
    {
        base.WriteStartConstructor(Name);
        checkDepth();
    }

    public override void WriteStartObject()
    {
        base.WriteStartObject();
        checkDepth();
    }

    private void checkDepth()
    {
        MaxObservedDepth = Math.Max(MaxObservedDepth,Top);
        if (Top > MaxDepth)
            throw new JsonserializationException(String.Format("Depth {0} Exceeds MaxDepth {1} at path \"{2}\"",Top,MaxDepth,Path));
    }
}

然后,要手动生成JSON字符串,您可以像这样使用它：

var setTings = new JsonserializerSetTings { MaxDepth = 10 };
        String json;
        try
        {
            using (var writer = new StringWriter())
            {
                using (var jsonWriter = new MaxDepthJsontextWriter(writer,setTings))
                {
                    Jsonserializer.Create(setTings).serialize(jsonWriter,myClass);
                    // Log the MaxObservedDepth here,if you want to.
                }
                json = writer.ToString();
            }
            Debug.WriteLine(json);
        }
        catch (Exception eX)
        {
            Debug.WriteLine(eX);
            json = null;
            throw;
        }

由于您的代码包含web-api,如果您要在Web API调用中执行此操作,则可以按照Rick Strahl的说明为JSON创建@L_266_11@mediaTypeFormatter：Using an alternate JSON Serializer in ASP.NET Web API;然后在生成json字符串时在OnWriteToStreamAsync方法中使用上面的代码.