ASP.NET MVC 3 Custom Type Conversion

问题:

Right now, I have a class defined as such:

public class Task
{
    public Guid TaskId { get; set; }
    public string TaskName { get; set; }

    [DataType(DataType.Time)]
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = @"{0:hh\:mm}")]
    public TimeSpan? TimeRequired { get; set; }
}

I would like to allow the user to also enter "2h" or "15m" for 2 hours or 15 minutes respectively. Is there a way I can allow these types of custom inputs? I was thinking of just creating a text box and then doing a custom check against that incoming value and cast it correctly to a TimeSpan. I wasn't sure if there was some type of "CustomConverter" much like the "CustomValidator" attribute.

Please let me know if anything is unclear.

Thanks in advance!

回答1:

I think I finally found it. According to Custom Model Binders you can just add a custom model binder in the Global.asax. Here is what I did. I added a class as such:

public class TimeSpanModelBinder : IModelBinder
{
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        ValueProviderResult value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
        string attemptedValue = value.AttemptedValue;

        // Custom parsing and return the TimeSpan? here.
    }
}

and then I added this line to my Global.asax.cs in public void Application_Start()

ModelBinders.Binders.Add(typeof(TimeSpan?), new TimeSpanModelBinder());

Works like a charm!