MvvmCross iOS UILabel AttributedText with Language converter - xamarin

Question

I create a custom control for UILabel with custom Kern parameter.
[Register("CustomLabelView"), DesignTimeVisible(true)]
public class CustomLabelView : UILabel
{
private float _textLetterSpacing;
public CustomLabelView(IntPtr handle) : base(handle)
{
}
[Export("TextLetterSpacing"), Browsable(true)]
public float TextLetterSpacing
{
get => _textLetterSpacing;
set
{
_textLetterSpacing = value;
SetNeedsDisplay();
}
}
public CustomLabelView()
{
Initialize();
}
public override void AwakeFromNib()
{
// Called when loaded from xib or storyboard.
Initialize();
}
void Initialize()
{
NSRange range = new NSRange(0, Text.Length);
var attributes = AttributedText.GetCoreTextAttributes(0, out range);
var attributedTitle = new NSAttributedString(Text, new CTStringAttributes() { KerningAdjustment = TextLetterSpacing, ForegroundColor = TextColor.CGColor, UnderlineStyle = attributes.UnderlineStyle });
AttributedText = attributedTitle;
SetNeedsDisplay();
}
}
I bind text to this control with language converter
set.Bind(CustomLabelView)
.For(c => c.Text)
.To(vm => vm.TextSource)
.WithConversion("Language", "AgreementText");
and underline property doesn't apply for bound text. Also I tried AttributedText property instead of Text. No any changes.
My LinkerPleaseInclude file contains this lines
public void Include(UILabel label)
{
label.Text = label.Text + "";
label.AttributedText = new NSAttributedString(label.AttributedText.ToString() + "");
}
Any ideas how to sort it out?

Answer 1

I changed the UnderlineStyle property's value to one of the enumeration of CTUnderlineStyle and it works for me.
namespace CoreText
{
//
// Summary:
// Specifies the style of an underline ornament.
//
// Remarks:
// To be added.
public enum CTUnderlineStyle
{
None = 0,
Single = 1,
Thick = 2,
Double = 9
}
}
Here is my code:
void Initialize()
{
this.Text = "This is some formatted text";
NSRange range = new NSRange(0, Text.Length);
var attributes = AttributedText.GetCoreTextAttributes(0, out range);
var attributedTitle = new NSAttributedString(Text, new CTStringAttributes() { KerningAdjustment = TextLetterSpacing, ForegroundColor = TextColor.CGColor, UnderlineStyle = CTUnderlineStyle.Single });
AttributedText = attributedTitle;
SetNeedsDisplay();
}
The underline appears,is this you want?

Answer 2

I just put Initialize method into Draw for my CustomLabel.
Here is the solution:
public override void Draw(CGRect rect)
{
Initialize();
base.Draw(rect);
}
private void Initialize()
{
var attributes = AttributedText.GetCoreTextAttributes(0, out _);
AttributedText = new NSMutableAttributedString(Text,
new CTStringAttributes
{
KerningAdjustment = TextLetterSpacing, Font = attributes.Font,
UnderlineStyle = attributes.UnderlineStyle
});
}