不能添加新的自定义模型绑定？错误使用相同的键的项已添加 [英] cant add new custom Model Binder ? error An item with the same key has already been added

问题描述

我米尝试添加一个新的自定义模型绑定，但没有成功。下面是我的code和基础工作的长期（删除格式和转换2,345.34至234534），它是做精：

I m trying to add a new custom Model Binder but not successful. Below is my code and in term of basic working (removing formatting and converting 2,345.34 to 234534) it is doing fine:

 public class TransactionModelBinder : IModelBinder
    {
        public object BindModel(ControllerContext controllerContext,
            ModelBindingContext bindingContext)
        {
            ValueProviderResult valueResult = bindingContext.ValueProvider.GetValue("Transaction.Price");
            ModelState modelState = new ModelState { Value = valueResult };
            object actualValue = null;
            object newValue = null;
            try
            {
                if (!string.IsNullOrEmpty(valueResult.AttemptedValue))
                {
                    newValue = valueResult.AttemptedValue.Replace(",", "");
                }
                actualValue = Convert.ToDecimal(newValue,
                    CultureInfo.CurrentCulture);
            }
            catch (FormatException e)
            {
                modelState.Errors.Add(e);
            }

            bindingContext.ModelState.Add(bindingContext.ModelName, modelState);
            return actualValue;
        }
    }

我的Global.asax code为如下：

My Global.asax code is given below:

 protected void Application_Start()
    {
        ModelBinders.Binders.Add(typeof(decimal), new CurrencyModelBinder());
        ModelBinders.Binders.Add(typeof(decimal), new TxTransactionModelBinder());

        AreaRegistration.RegisterAllAreas();

        WebApiConfig.Register(GlobalConfiguration.Configuration);
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
        RouteConfig.RegisterRoutes(RouteTable.Routes);
        BundleConfig.RegisterBundles(BundleTable.Bundles);
       // RouteTable.Routes.MapHubs();


    }

问题：
在运行code TransactionModelBinder做工精细，但在Global.asax中我得到了follwoing错误：

Issue: On running code TransactionModelBinder work fine but in global.asax I got the follwoing error:

具有相同键的项已被添加。

我能理解 typeof运算（十进制）在两个定制粘合剂是造成这个问题。

I can understand typeof(decimal) in two custom binders is causing this issue.

您可以请引导和帮助我如何解决这个问题。

Can you please guide and help me on how to fix this.

推荐答案

您只能有每个数据类型的单一模式粘合剂。我不能完全肯定的区别是两个粘合剂之间什么，但也许你可以他们的逻辑组合成一个单一的模型粘合剂。如果你确实需要两个不同的模型粘合剂，那么也许你需要创建具体到每个模型绑定两个不同的数据类型。

You can only have a single model binder per datatype. I'm not entirely sure what the difference is between the two binders, but perhaps you could combine their logic into a single model binder. If you absolutely need two different model binders, then perhaps you need to create two different datatypes specific to each model binder.

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