c# - Nancy decimal 属性绑定(bind)不起作用

Question

我在绑定(bind)小数属性时遇到问题:

Oh noes! ---> Nancy.ModelBinding.ModelBindingException: Unable to bind to type: Nancy.Models.SomeModel
at Nancy.ModelBinding.DefaultBinder.Bind(NancyContext context, Type modelType, Object instance, BindingConfig configuration, String[] blackList)
at Nancy.ModelBinding.DynamicModelBinderAdapter.TryConvert(ConvertBinder binder, Object& result)
at CallSite.Target(Closure , CallSite , Object )
at System.Dynamic.UpdateDelegates.UpdateAndExecute1[T0,TRet](CallSite site, T0 arg0)
at Nancy.ModelBinding.ModuleExtensions.Bind[TModel](INancyModule module)
at KBZServisNancy.Modules.SomeModule.<.ctor>b__2(Object x) in d:\Nancy\Modules\SomeDecimalModule.cs:line 38
at CallSite.Target(Closure , CallSite , Func`2 , Object )
at Nancy.Routing.Route.<>c__DisplayClass4.b__3(Object parameters, CancellationToken context)
--- End of inner exception stack trace ---
at Nancy.NancyEngine.InvokeOnErrorHook(NancyContext context, ErrorPipeline pipeline, Exception ex)
at Nancy.NancyEngine.InvokeOnErrorHook(NancyContext context, ErrorPipeline pipeline, Exception ex)

如果 decimal 属性的值是例如 20,50，则绑定(bind)工作正常，但如果值为 20.50，我会收到上层错误消息。据此，文化敏感可能存在问题，但上下文文化是{en-US}。已经有一些此类问题Culture model binding他们已经解决了，所以我不知道问题出在哪里。我在控制台应用程序中使用自托管的 Nancy v0.23。提前感谢您的帮助。

Answer 1

在当前的 Nancy 版本中，只需编写自己的 ITypeConverter

/// <summary>
/// Nancy converter to convert numeric types with InvariantCulture.
/// </summary>
public class NancyNumericConverter : ITypeConverter
{
    public bool CanConvertTo(Type destinationType, BindingContext context)
    {
        return destinationType.IsNumeric();
    }

    public object Convert(string input, Type destinationType, BindingContext context)
    {
        if (string.IsNullOrEmpty(input))
        {
            return null;
        }

        return System.Convert.ChangeType(input, destinationType, CultureInfo.InvariantCulture);
    }
}

(我也更新了 issue https://github.com/NancyFx/Nancy/issues/1587。)