CODEWITHSUNDEEP
wpfbindingfont-sizedynamicresource
vercin
vercin

Reputation: 220

WPF How to set pt(12pt etc..) via DynamicResource for FontSize property

I can use: 

<TextBlock Text="Some Textes" FontSize="12pt" />

It works normally. But I want to use the DynamicResource extension, is it possible?

This does not work:

<TextBlock Text="Some Textes" FontSize="{DynamicResource SomeResources}" />

SomeResources:

<System:Stringx:Key="SomeResources">12pt</System:String>

I do not want to use an AttachedBehavior. I know, I can solve my problem with it (using FontSizeConverter).

Upvotes: 2

Views: 4865

Answers (2)

Viv
Viv

Reputation: 17380

Update:

I see you've edited your question and taken out the binding option. If your only wanting to get this from a xaml resource, you'd need to use a MarkupExtension. You can find the MarkupExtension and the usage here. This will work fine for your case.

Orig reply:

FontSize is of type System:Double Documentation.

Next default Binding for FontSize assumes pixels at device independent scale but since you need pt's we can use a converter such as:

using System.Globalization;
using System.Windows;
using System.Windows.Data;

class ConvertFromPoint : IValueConverter
{
  public object Convert(object value, Type targetType, object parameter, CultureInfo culture) {
    var convertFrom = new FontSizeConverter().ConvertFrom(value.ToString());
    if (convertFrom != null)
      return (double) convertFrom;
    return 1;
  }

  public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) {
    throw new NotImplementedException();
  }
}

and usage:

<TextBlock FontSize="{Binding StringProperty, Converter={StaticResource ConvertFromPointConverter}}">Some Text</TextBlock>

Alternate:

If you do not want to use converters and FontSizeConverter just do the calculation in your property getter.

something like:

private double _someFontval;
public double SomeFontVal {
  get {
    return _someFontval * 96 / 72;
  }

  set {
    _someFontval = value;
  }
}

usage:

//.cs
SomeFontVal = 12.0;

//.xaml
<TextBlock FontSize="{Binding SomeFontVal}">Some Text</TextBlock>

Upvotes: 2

ChrisO
ChrisO

Reputation: 5465

I believe you can just bind it as a int double

<System:Double x:Key="SomeResources">12</System:Double>

Upvotes: 0

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