ASP.NET MVC如何处理数据库中的动态日期时间格式

Question

In my ASP.NET MVC 5 dwith EF 6 project, I have a database where datetime format is stored as string like "dd-MM-yyyy". User can change this format any time. User will use the given format in the date fields in the view. But when they will post that. Automatically it will bind as a DateTime for that property. I am statically handling it by the following code

[DataType(DataType.Time), DisplayFormat(DataFormatString = "{HH:mm}", ApplyFormatInEditMode = true)]
public DateTime? EndingTime { get; set; }

public string EndingTimeValue
{
    get
    {
        return EndingTime.HasValue ? EndingTime.Value.ToString("HH:mm") : string.Empty;
    }

    set
    {
        EndingTime = DateTime.Parse(value);
    }
}

but I know it's not a best way to do that. There may need a model binder or filter or any kind of custom attribute. I will be greatly helped if you give me a efficient solution with sample code. Thanks in advance.

NB: I am using razor view engine. and my solution consists of 7 projects. So there is no chance of using Session in model. Again I have a base repository class for using entity framework.

Answer 1

People usually store the datetime in the database as a datetime. Then wherever you do a translation from datetime to string that datetime can be displayed in a format that depends on the culture of the viewer. By doing this you can quickly make a page with datetime formats that will format the datetimes nicely wherever you are.

change the culture you pass to the toString and the format changes.

please see this MSDN page for more info about it.

edit: (see comments below) anywhere on server:

string WhatYouWant = yourTime.ToCustomFormat()

and create an extension method for the datetime that gets the format out of the database and returns a string in the correct format.

public static class MyExtensions
    {
        public static string ToCustomFormat(this DateTime yourTime)
        {
                  // Get the following var out of the database
      String format = "MM/dd/yyyy hh:mm:sszzz";

      // Converts the local DateTime to a string 
      // using the custom format string and display.
      String result = yourTime.ToString(format);
      return result;
        }
    }   

This will allow you to call it anywhere anytime on your server. You can't access the method client side in javascript. I hope this helps.

(To be honest I'm a new developer too and still have a lot to learn ^^)

Answer 2

I have tried many options regarding this problem. Now what I am doing is created an action filter to catch all the DateTime and nullable DateTime Fields. Here I am providing the binder.

public class DateTimeBinder : DefaultModelBinder
{
    public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {

        var value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);


        DateTime date;
        var displayFormat = SmartSession.DateTimeFormat;

        if (DateTime.TryParseExact(value.AttemptedValue, displayFormat, CultureInfo.InvariantCulture, DateTimeStyles.None, out date))
        {
            return date;
        }
        else
        {
            bindingContext.ModelState.AddModelError(bindingContext.ModelName,"Invalid Format");
        }


        return base.BindModel(controllerContext, bindingContext);
    }
}

in views the code I am formatting the date using same date format.