Question

Suppose if I have an Annotation like the following

[DisplayFormat(DataFormatString = "{0:#.00#}", ApplyFormatInEditMode = true)]

It works great. But suppose I want to replace the DataFormatString in real time i.e. some times like this {0:#.00#} and sometimes {0:#.000#} based on some application settings the user chooses. Is there a way to do that?

I tried storing the format string in a global variable, but it gives me the following error.

An attribute argument must be a constant expression, typeof expression
or array creation expression of an attribute parameter type

If I make the global variable constant it works but then the purpose is lost. Any advice on a work around?

Basically I would like to give the users an option to set the decimal spaces universally with out having to implement the feature on a per View/Controller basis.

I know I can put the culture using NumberFormat.CurrencyDecimalDigits. But this will ignore Zeros after the decimal.

Answer 1

Attribute requires constant string, you can’t change that. Also this attribute does not provide ability to provide resource name. So, I think best way to you is creating DisplayTemplate and EditorTemplate for this property.

[UIHint("Bar")]
public decimal Bar { get; set; }

And in Bar template you can change format based on some application settings chosen by user:

@model decimal

@Model.ToString(HttpContext.Current.Session["format"].ToString())