Xamarin Forms: Button text font size based on the size of the button

Question

How can I adapt the font size of a button based of the size of the button itself?

Im using Xamarin Forms in the newest version (5.0.0.2337).

Answer 1

This can be achieved by Custom Renderer

Below is code snippets for your reference:

Code in Xaml:

  <local:MyButton  Text="My Button" WidthRequest="100" HeightRequest="50"/>

MyButton in Shared Project:

   public class MyButton : Button
   {
       public MyButton()
       {
       }
   }

In Android: MyAndroidButton.cs:

namespace AppHybridWebView.Droid
{
    public class MyAndroidButton :  ButtonRenderer
    {
        public MyAndroidButton(Context context) : base(context)
        {
        }
        protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Button> e)
        {
            base.OnElementChanged(e);
            if (Control != null)
            {
                SetNativeControl(new AutoFitButton(Context));
            }
        }
        protected override void OnDraw(Canvas canvas)
        {
            base.OnDraw(canvas);
        }
     }
        public class AutoFitButton : Android.Widget.Button
       {
          public AutoFitButton(Context context) : base(context)
          {
        }
        protected override void OnDraw(Canvas canvas)
       {
           base.OnDraw(canvas);
           SetAutoSizeTextTypeWithDefaults(AutoSizeTextType.Uniform);
       }
    }
}

In iOS MyiOSButton.cs:

namespace AppHybridWebView.iOS
{
    public class MyiOSButton : ButtonRenderer
    {
        public MyiOSButton()
        {
        }
        protected override void OnElementChanged(ElementChangedEventArgs<Button> e)
        {
            base.OnElementChanged(e);
            if (Control != null)
            {
                Control.TitleLabel.SizeToFit();
                Control.TitleLabel.AdjustsFontSizeToFitWidth = true;
            }
        }
    }
}