淘汰赛和MVC3：发布JSON行动，序列化两次？无法转换为C＃对象？ [英] Knockout and MVC3: Posting JSON to action, serializing twice? Can't convert to C# objects?

问题描述

我有一个被通过保存方法发布了淘汰赛型号：

I've got a Knockout Model that gets posted via a save method:

 self.save = function(form) {
        ko.utils.postJson($("form")[0], self);
    };

我检查，以确保所有的数据正确张贴（它是）要求：

I check the request to make sure all the data is properly being posted (it is):

然而，当我到达我的行动：

However, when I get to my action:

 [HttpPost]
 public ActionResult Create(EquipmentCreateModel equipmentCreateModel)
 {
    /stuff here
 }

大厦code和客房包含转义引号和标识是完全不为空，但有计数0：

BuildingCode and Room contain escaped quotes, and identifiers is totally not null but has a count of 0:

和我的ModelState是无效的，有一个错误，在标识符其中有企图值属性：

And my ModelState is not valid, there is one error, for the Identifiers property which has an attempted value of :

和异常信息是：

参数转换，从类型'System.String'输入'System.Collections.Generic.KeyValuePair`2 [的System.Guid，mscorlib程序，版本= 4.0.0.0，文化=中性公钥= b77a5c561934e089]，[ System.String，mscorlib程序，版本= 4.0.0.0，文化=中性公钥= b77a5c561934e089]]'失败，因为没有类型转换器可以将这些类型之间的转换。

"The parameter conversion from type 'System.String' to type 'System.Collections.Generic.KeyValuePair`2[[System.Guid, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]' failed because no type converter can convert between these types."

我的模型：

public class EquipmentCreateModel
{
//used to populate form drop downs
public ICollection<Building> Buildings { get; set; }
public ICollection<IdentifierType> IdentifierTypes { get; set; }

[Required]
[Display(Name = "Building")]
public string BuildingCode { get; set; }

[Required]
public string Room { get; set; }

[Required]
[Range(1, 100, ErrorMessage = "You must add at least one identifier.")]
public int IdentifiersCount { get; set; } //used as a hidden field to validate the list
public string IdentifierValue { get; set; } //used only for knockout viewmodel binding

public IDictionary<Guid, string> Identifiers { get; set; }
}

现在开始我还以为是敲一个问题，但后来我发现数据没有被张贴在请求正确。我固定的，仍然有同样的问题。我以为MVC3自动转换Json的呢？为什么我的简单的属性出现在转义引号，为什么不能我的身份集合正确地从发布的数据填充？

Now first I thought it was a problem with knockout, but then I found out the data wasn't being posted in the request correctly. I fixed that and still had the same problem. I thought MVC3 automatically converts Json now? Why are my simple properties appearing in escaped quotes and why can't my identities collection properly populate from the posted data?

推荐答案

试试这个：

 [HttpPost]
 public ActionResult Create([FromJson] EquipmentCreateModel equipmentCreateModel)
 {
    //stuff here
 }

其中FromJson是：

where FromJson is:

   public class FromJsonAttribute : CustomModelBinderAttribute
    {
      private readonly static JavaScriptSerializer serializer = new JavaScriptSerializer();
      public override IModelBinder GetBinder()
      {
         return new JsonModelBinder();
      }

      private class JsonModelBinder : IModelBinder
      {
         public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
         {
           var stringified = controllerContext.HttpContext.Request[bindingContext.ModelName];
           if (string.IsNullOrEmpty(stringified))
                return null;
           return serializer.Deserialize(stringified, bindingContext.ModelType);
          }
     }
 }

这是摘自：
的http://blog.stevensanderson.com/2010/07/12/editing-a-variable-length-list-knockout-style/
您应检查意见，因为有对FromJsonAttribute做一些修改。

This is taken from: http://blog.stevensanderson.com/2010/07/12/editing-a-variable-length-list-knockout-style/ you should check the comments to as there are some modification for the FromJsonAttribute.

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