ASP.Net EditorFor with custom expression

Question

The built-in EditorFor does only work with member access expressions.

But in one scenario, I need to multiply the value with 100 and have that inside a text box. That is because the value represents a percentage and the user should be able to input 27 which is internally stored as 0.27. For this it would be nice to have something like EditorFor(m => m.MyValue * 100).

Is there any equivalent for that?

Answer 1

You can try adding an attribute to your property

[DisplayFormat(DataFormatString = "{0:P2}", ApplyFormatInEditMode = true)]
    public decimal MyValueASPercentage { get; set; }

Now a value of 0.27 will appear as 27 % on your page. Hope that helps

Answer 2

Just add something like MyValueAsPercentage to your view model:

public class MyDataModel
{
    public double MyValue { get; set; }
}

// ...

public class MyViewModel
{
    public double MyValueAsPercentage { get; set; }

    public MyViewModel(MyDataModel dataModel)
    {
        this.MyValueAsPercentage = dataModel.MyValue * 100;
    }

    public MyDataModel ToDataModel()
    {
        return new MyDataModel() { MyValue = MyValueAsPercentage / 100 };
    }
}

Now you can use the same member access expression over your view model:

Html.EditorFor(m => m.MyValueAsPercentage)

Hope this helps.