自定义ModelBinder不适用于Nullable类型

Question

我有以下针对DateTime的自定义ModelBinder：

public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        ValueProviderResult value = null;
        try
        {
            value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
            return DateTime.ParseExact(value.AttemptedValue, _customFormat, CultureInfo.InvariantCulture);
        }
        catch (Exception)
        {
            // If there is a place where DateTime got used which "Bypassed" our EditorTemplate, it means the format will be the default format.
            // So let's allow the Model Binder to at least try to Parse the date with the default format.
            return DateTime.Parse(value.AttemptedValue);
        }
    }

如果我在Action中将参数指定为可为null的DateTime（ DateTime? dob ），则不会触发ModelBinder。

如何使ModelBinder在可为空的DateTime上工作？

Answer 1

您需要注册两次，如下所示：

ModelBinders.Binders.Add(typeof (DateTime), new DateTimeModelBinder());
ModelBinders.Binders.Add(typeof (DateTime?), new DateTimeModelBinder());