在ASP.NET MVC中设置默认的JSON序列化程序
在ASP.NET MVC中设置默认的JSON序列化程序
提问于 2013-01-30 04:35:43
我正在开发一个已部分转换为MVC的现有应用程序。每当控制器使用JSON ActionResult响应时，枚举都是以数字而不是字符串名称的形式发送的。听起来默认的序列化程序应该是JSON.Net，它应该以枚举的名称发送枚举，而不是整数表示，但这里的情况并非如此。
我是否缺少将其设置为默认序列化程序的web.config设置？或者，是否有其他设置需要更改？
回答 2
Stack Overflow用户
回答已采纳
发布于 2013-01-30 04:47:40
在ASP.Net MVC4中，JsonResult类中使用的默认JavaScript序列化程序仍然是JavaScriptSerializer (您可以在code中检查它)
我认为您将其与ASP.Net Web.API混淆了，其中JSON.Net是默认的JS序列化程序，但MVC4不使用它。
所以你需要配置JSON.Net来使用MVC4 (基本上你需要创建你自己的JsonNetResult)，有很多关于它的文章：
- ASP.NET MVC and Json.NET
- Using JSON.NET as the default JSON serializer in ASP.NET MVC 3 - is it possible?
如果您还想在模型绑定期间为控制器操作参数使用JSON.Net，那么您需要编写自己的ValueProviderFactory实现。
并且您需要向以下位置注册您的实现：
ValueProviderFactories.Factories
.Remove(ValueProviderFactories.Factories
.OfType<JsonValueProviderFactory>().Single());
ValueProviderFactories.Factories.Add(new MyJsonValueProviderFactory());您可以使用内置的JsonValueProviderFactory作为示例，或者阅读本文：ASP.NET MVC 3 – Improved JsonValueProviderFactory using Json.Net
Stack Overflow用户
发布于 2018-06-03 19:08:30
ASP.NET MVC 5修复：
我还没有准备好更改到Json.NET，在我的例子中，错误发生在请求过程中。在我的场景中，最好的方法是修改实际的JsonValueProviderFactory，这将修复应用到全局项目，并且可以通过编辑global.cs文件来完成。
JsonValueProviderConfig.Config(ValueProviderFactories.Factories);添加web.config条目：
<add key="aspnet:MaxJsonLength" value="20971520" />然后创建以下两个类
public class JsonValueProviderConfig
{
public static void Config(ValueProviderFactoryCollection factories)
{
var jsonProviderFactory = factories.OfType<JsonValueProviderFactory>().Single();
factories.Remove(jsonProviderFactory);
factories.Add(new CustomJsonValueProviderFactory());
}
}这基本上是System.Web.Mvc中默认实现的精确副本，但增加了一个可配置的web.config应用设置值aspnet:MaxJsonLength。
public class CustomJsonValueProviderFactory : ValueProviderFactory
{
/// <summary>Returns a JSON value-provider object for the specified controller context.</summary>
/// <returns>A JSON value-provider object for the specified controller context.</returns>
/// <param name="controllerContext">The controller context.</param>
public override IValueProvider GetValueProvider(ControllerContext controllerContext)
{
if (controllerContext == null)
throw new ArgumentNullException("controllerContext");
object deserializedObject = CustomJsonValueProviderFactory.GetDeserializedObject(controllerContext);
if (deserializedObject == null)
return null;
Dictionary<string, object> strs = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
CustomJsonValueProviderFactory.AddToBackingStore(new CustomJsonValueProviderFactory.EntryLimitedDictionary(strs), string.Empty, deserializedObject);
return new DictionaryValueProvider<object>(strs, CultureInfo.CurrentCulture);
}
private static object GetDeserializedObject(ControllerContext controllerContext)
{
if (!controllerContext.HttpContext.Request.ContentType.StartsWith("application/json", StringComparison.OrdinalIgnoreCase))
return null;
string fullStreamString = (new StreamReader(controllerContext.HttpContext.Request.InputStream)).ReadToEnd();
if (string.IsNullOrEmpty(fullStreamString))
return null;
var serializer = new JavaScriptSerializer()
{
MaxJsonLength = CustomJsonValueProviderFactory.GetMaxJsonLength()
};
return serializer.DeserializeObject(fullStreamString);
}
private static void AddToBackingStore(EntryLimitedDictionary backingStore, string prefix, object value)
{
IDictionary<string, object> strs = value as IDictionary<string, object>;
if (strs != null)
{
foreach (KeyValuePair<string, object> keyValuePair in strs)
CustomJsonValueProviderFactory.AddToBackingStore(backingStore, CustomJsonValueProviderFactory.MakePropertyKey(prefix, keyValuePair.Key), keyValuePair.Value);
return;
}
IList lists = value as IList;
if (lists == null)
{
backingStore.Add(prefix, value);
return;
}
for (int i = 0; i < lists.Count; i++)
{
CustomJsonValueProviderFactory.AddToBackingStore(backingStore, CustomJsonValueProviderFactory.MakeArrayKey(prefix, i), lists[i]);
}
}
private class EntryLimitedDictionary
{
private static int _maximumDepth;
private readonly IDictionary<string, object> _innerDictionary;
private int _itemCount;
static EntryLimitedDictionary()
{
_maximumDepth = CustomJsonValueProviderFactory.GetMaximumDepth();
}
public EntryLimitedDictionary(IDictionary<string, object> innerDictionary)
{
this._innerDictionary = innerDictionary;
}
public void Add(string key, object value)
{
int num = this._itemCount + 1;
this._itemCount = num;
if (num > _maximumDepth)
{
throw new InvalidOperationException("The length of the string exceeds the value set on the maxJsonLength property.");
}
this._innerDictionary.Add(key, value);
}
}
private static string MakeArrayKey(string prefix, int index)
{
return string.Concat(prefix, "[", index.ToString(CultureInfo.InvariantCulture), "]");
}
private static string MakePropertyKey(string prefix, string propertyName)
{
if (string.IsNullOrEmpty(prefix))
{
return propertyName;
}
return string.Concat(prefix, ".", propertyName);
}
private static int GetMaximumDepth()
{
int num;
NameValueCollection appSettings = ConfigurationManager.AppSettings;
if (appSettings != null)
{
string[] values = appSettings.GetValues("aspnet:MaxJsonDeserializerMembers");
if (values != null && values.Length != 0 && int.TryParse(values[0], out num))
{
return num;
}
}
return 1000;
}
private static int GetMaxJsonLength()
{
int num;
NameValueCollection appSettings = ConfigurationManager.AppSettings;
if (appSettings != null)
{
string[] values = appSettings.GetValues("aspnet:MaxJsonLength");
if (values != null && values.Length != 0 && int.TryParse(values[0], out num))
{
return num;
}
}
return 1000;
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/14591750
复制相关文章
相似问题