StringWriter内存超出范围异常

Question

I have a method ExecuteResult , which is throwing a System.OutOfMemoryException at the line Response.Write(sw.ToString()) . This is happening because the StringWriter object is too large in memory for the ToString ; it fills up the memory.

I've been looking around for a solution but can't seem to find a simple clean solution to the problem. Any ideas would be greatly appreciated.

Code:

public class JsonNetResult : JsonResult
{
    public JsonNetResult()
    {
        Settings = new JsonSerializerSettings
        {
            ReferenceLoopHandling = ReferenceLoopHandling.Error
        };
    }

    public JsonSerializerSettings Settings { get; private set; }

    public override void ExecuteResult(ControllerContext context)
    {
        if (this.Data != null)
        {
            if (context == null)
                throw new ArgumentNullException("context");
            if (this.JsonRequestBehavior == JsonRequestBehavior.DenyGet && string.Equals(context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase))
                throw new InvalidOperationException("JSON GET is not allowed");

            HttpResponseBase response = context.HttpContext.Response;
            response.ContentType = string.IsNullOrEmpty(this.ContentType) ? "application/json" : this.ContentType;

            if (this.ContentEncoding != null)
                response.ContentEncoding = this.ContentEncoding;


            var scriptSerializer = JsonSerializer.Create(this.Settings);

            using (var sw = new StringWriter())
            {
                    scriptSerializer.Serialize(sw, this.Data);
                    //outofmemory exception is happening here
                    response.Write(sw.ToString());
            }
        }
    }
}

Answer 1

I think the problem is you are buffering all of the JSON into a StringWriter and then trying to write it out in one big chunk instead of streaming it out to the response.

Try replacing this code:

using (var sw = new StringWriter())
{
    scriptSerializer.Serialize(sw, this.Data);
    //outofmemory exception is happening here
    response.Write(sw.ToString());
}

With this:

using (StreamWriter sw = new StreamWriter(response.OutputStream, ContentEncoding))
using (JsonTextWriter jtw = new JsonTextWriter(sw))
{
    scriptSerializer.Serialize(jtw, this.Data);
}