JsonValueProviderFactory 抛出“请求太大"；

问题描述

我收到一个异常，即 JSON 请求太大而无法反序列化.

I'm getting an exception that the JSON request was too large to be deserialized.

它来自 JsonValueProviderFactory....

It's coming from the JsonValueProviderFactory....

MVC 应用程序目前有一个使用 Json.Net 的自定义模型绑定器，反序列化 json 数据没有问题.但是，我假设默认的 JSON 值提供程序出错了?还是有一些奇怪的限制?

The MVC App currently has a custom model binder using Json.Net which has no problem deserializing the json data. However I'm assuming the default JSON value provider is tripping up? or has some weird limit built into it?

这可能与 MVC4 的最新版本有关，因为在使用先前版本的 MVC4 时，大量 JSON 没有问题.

It may be be to do with the latest release of MVC4 as when using the previous build of MVC4 there were no problems with large amounts of JSON.

那么，有没有办法改变实际json值绑定器的设置?

So, is there a way to change the setting s of the actual json value binder?

通过 http://haacked.com/archive/2011/06/30/whatrsquos-the-difference-between-a-value-provider-and-model-binder.aspx

我的印象是它是一些自定义的东西，将它变成了字典......我找不到任何与它相关的源代码，或者是否有任何我可以更改的设置?

I get the impression it's some custom thing that turns it into a dictionary....I can't find any source code related to it or if there are any settings I can change?

或者我可以使用替代的 ValueBinder 吗?

Or is there an alternative ValueBinder I could use?

或任何其他选项?

Server Error in '/' Application.
The JSON request was too large to be deserialized.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: The JSON request was too large to be deserialized.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[InvalidOperationException: The JSON request was too large to be deserialized.]
   System.Web.Mvc.EntryLimitedDictionary.Add(String key, Object value) +464621
   System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value) +413
   System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value) +164
   System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value) +164
   System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value) +373
   System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value) +164
   System.Web.Mvc.JsonValueProviderFactory.GetValueProvider(ControllerContext controllerContext) +116
   System.Web.Mvc.<>c__DisplayClassc.<GetValueProvider>b__7(ValueProviderFactory factory) +34

       System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +151
   System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +177

推荐答案

如果您使用 JSON.NET 进行序列化/反序列化，您可以使用自定义的 JsonValueProviderFactory 替换默认的 JsonValueProviderFactory，如 这篇博文:

If you use JSON.NET for serialization/deserialization, you could substitute the default JsonValueProviderFactory with a custom one as shown in this blog post:

public sealed class JsonDotNetValueProviderFactory : ValueProviderFactory
{
   public override IValueProvider GetValueProvider(ControllerContext controllerContext)
   {
        if (controllerContext == null)
            throw new ArgumentNullException("controllerContext");

        if (!controllerContext.HttpContext.Request.ContentType.StartsWith("application/json", StringComparison.OrdinalIgnoreCase))
            return null;

        var reader = new StreamReader(controllerContext.HttpContext.Request.InputStream);
        var bodyText = reader.ReadToEnd();

        return String.IsNullOrEmpty(bodyText) ? null : new DictionaryValueProvider<object>(JsonConvert.DeserializeObject<ExpandoObject>(bodyText, new ExpandoObjectConverter()) , CultureInfo.CurrentCulture);
    }
}

并在您的 Application_Start 中:

ValueProviderFactories.Factories.Remove(ValueProviderFactories.Factories.OfType<JsonValueProviderFactory>().FirstOrDefault());
ValueProviderFactories.Factories.Add(new JsonDotNetValueProviderFactory());

如果您想坚持使用使用 JavaScriptSerializer 类，您可以调整 maxJsonLength web.config 中的属性:

and if you want to stick with the default factory which uses the JavaScriptSerializer class you could adjust the maxJsonLength property in your web.config:

<system.web.extensions>
    <scripting>
        <webServices>
            <jsonSerialization maxJsonLength="2147483644"/>
        </webServices>
    </scripting>
</system.web.extensions>

这篇关于JsonValueProviderFactory 抛出“请求太大"；的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！