Apply stroke to a textblock in WPF
I modified the most voted answer with several fixes, including:
Fix so texts with a single line would show when using UseLayoutRounding.
Outlines would show outside the text instead of in the middle of the border.
The pen is created only once instead of on each render.
Fix so it won't crash when the text is set to null.
Fix so outline uses proper round caps.
using System;
using System.ComponentModel;
using System.Globalization;
using System.Windows;
using System.Windows.Documents;
using System.Windows.Markup;
using System.Windows.Media;
[ContentProperty("Text")]
public class OutlinedTextBlock : FrameworkElement
{
private void UpdatePen() {
_Pen = new Pen(Stroke, StrokeThickness) {
DashCap = PenLineCap.Round,
EndLineCap = PenLineCap.Round,
LineJoin = PenLineJoin.Round,
StartLineCap = PenLineCap.Round
};
InvalidateVisual();
}
public static readonly DependencyProperty FillProperty = DependencyProperty.Register(
"Fill",
typeof(Brush),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(Brushes.Black, FrameworkPropertyMetadataOptions.AffectsRender));
public static readonly DependencyProperty StrokeProperty = DependencyProperty.Register(
"Stroke",
typeof(Brush),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(Brushes.Black, FrameworkPropertyMetadataOptions.AffectsRender, StrokePropertyChangedCallback));
private static void StrokePropertyChangedCallback(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs) {
(dependencyObject as OutlinedTextBlock)?.UpdatePen();
}
public static readonly DependencyProperty StrokeThicknessProperty = DependencyProperty.Register(
"StrokeThickness",
typeof(double),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(1d, FrameworkPropertyMetadataOptions.AffectsRender, StrokePropertyChangedCallback));
public static readonly DependencyProperty FontFamilyProperty = TextElement.FontFamilyProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontSizeProperty = TextElement.FontSizeProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontStretchProperty = TextElement.FontStretchProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontStyleProperty = TextElement.FontStyleProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontWeightProperty = TextElement.FontWeightProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextProperty = DependencyProperty.Register(
"Text",
typeof(string),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextInvalidated));
public static readonly DependencyProperty TextAlignmentProperty = DependencyProperty.Register(
"TextAlignment",
typeof(TextAlignment),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextDecorationsProperty = DependencyProperty.Register(
"TextDecorations",
typeof(TextDecorationCollection),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextTrimmingProperty = DependencyProperty.Register(
"TextTrimming",
typeof(TextTrimming),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextWrappingProperty = DependencyProperty.Register(
"TextWrapping",
typeof(TextWrapping),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(TextWrapping.NoWrap, OnFormattedTextUpdated));
private FormattedText _FormattedText;
private Geometry _TextGeometry;
private Pen _Pen;
public Brush Fill
{
get { return (Brush)GetValue(FillProperty); }
set { SetValue(FillProperty, value); }
}
public FontFamily FontFamily
{
get { return (FontFamily)GetValue(FontFamilyProperty); }
set { SetValue(FontFamilyProperty, value); }
}
[TypeConverter(typeof(FontSizeConverter))]
public double FontSize
{
get { return (double)GetValue(FontSizeProperty); }
set { SetValue(FontSizeProperty, value); }
}
public FontStretch FontStretch
{
get { return (FontStretch)GetValue(FontStretchProperty); }
set { SetValue(FontStretchProperty, value); }
}
public FontStyle FontStyle
{
get { return (FontStyle)GetValue(FontStyleProperty); }
set { SetValue(FontStyleProperty, value); }
}
public FontWeight FontWeight
{
get { return (FontWeight)GetValue(FontWeightProperty); }
set { SetValue(FontWeightProperty, value); }
}
public Brush Stroke
{
get { return (Brush)GetValue(StrokeProperty); }
set { SetValue(StrokeProperty, value); }
}
public double StrokeThickness
{
get { return (double)GetValue(StrokeThicknessProperty); }
set { SetValue(StrokeThicknessProperty, value); }
}
public string Text
{
get { return (string)GetValue(TextProperty); }
set { SetValue(TextProperty, value); }
}
public TextAlignment TextAlignment
{
get { return (TextAlignment)GetValue(TextAlignmentProperty); }
set { SetValue(TextAlignmentProperty, value); }
}
public TextDecorationCollection TextDecorations
{
get { return (TextDecorationCollection)GetValue(TextDecorationsProperty); }
set { SetValue(TextDecorationsProperty, value); }
}
public TextTrimming TextTrimming
{
get { return (TextTrimming)GetValue(TextTrimmingProperty); }
set { SetValue(TextTrimmingProperty, value); }
}
public TextWrapping TextWrapping
{
get { return (TextWrapping)GetValue(TextWrappingProperty); }
set { SetValue(TextWrappingProperty, value); }
}
public OutlinedTextBlock() {
UpdatePen();
TextDecorations = new TextDecorationCollection();
}
protected override void OnRender(DrawingContext drawingContext) {
EnsureGeometry();
drawingContext.DrawGeometry(null, _Pen, _TextGeometry);
drawingContext.DrawGeometry(Fill, null, _TextGeometry);
}
protected override Size MeasureOverride(Size availableSize) {
EnsureFormattedText();
// constrain the formatted text according to the available size
double w = availableSize.Width;
double h = availableSize.Height;
// the Math.Min call is important - without this constraint (which seems arbitrary, but is the maximum allowable text width), things blow up when availableSize is infinite in both directions
// the Math.Max call is to ensure we don't hit zero, which will cause MaxTextHeight to throw
_FormattedText.MaxTextWidth = Math.Min(3579139, w);
_FormattedText.MaxTextHeight = Math.Max(0.0001d, h);
// return the desired size
return new Size(Math.Ceiling(_FormattedText.Width), Math.Ceiling(_FormattedText.Height));
}
protected override Size ArrangeOverride(Size finalSize) {
EnsureFormattedText();
// update the formatted text with the final size
_FormattedText.MaxTextWidth = finalSize.Width;
_FormattedText.MaxTextHeight = Math.Max(0.0001d, finalSize.Height);
// need to re-generate the geometry now that the dimensions have changed
_TextGeometry = null;
return finalSize;
}
private static void OnFormattedTextInvalidated(DependencyObject dependencyObject,
DependencyPropertyChangedEventArgs e) {
var outlinedTextBlock = (OutlinedTextBlock)dependencyObject;
outlinedTextBlock._FormattedText = null;
outlinedTextBlock._TextGeometry = null;
outlinedTextBlock.InvalidateMeasure();
outlinedTextBlock.InvalidateVisual();
}
private static void OnFormattedTextUpdated(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e) {
var outlinedTextBlock = (OutlinedTextBlock)dependencyObject;
outlinedTextBlock.UpdateFormattedText();
outlinedTextBlock._TextGeometry = null;
outlinedTextBlock.InvalidateMeasure();
outlinedTextBlock.InvalidateVisual();
}
private void EnsureFormattedText() {
if (_FormattedText != null) {
return;
}
_FormattedText = new FormattedText(
Text ?? "",
CultureInfo.CurrentUICulture,
FlowDirection,
new Typeface(FontFamily, FontStyle, FontWeight, FontStretch),
FontSize,
Brushes.Black);
UpdateFormattedText();
}
private void UpdateFormattedText() {
if (_FormattedText == null) {
return;
}
_FormattedText.MaxLineCount = TextWrapping == TextWrapping.NoWrap ? 1 : int.MaxValue;
_FormattedText.TextAlignment = TextAlignment;
_FormattedText.Trimming = TextTrimming;
_FormattedText.SetFontSize(FontSize);
_FormattedText.SetFontStyle(FontStyle);
_FormattedText.SetFontWeight(FontWeight);
_FormattedText.SetFontFamily(FontFamily);
_FormattedText.SetFontStretch(FontStretch);
_FormattedText.SetTextDecorations(TextDecorations);
}
private void EnsureGeometry() {
if (_TextGeometry != null) {
return;
}
EnsureFormattedText();
_TextGeometry = _FormattedText.BuildGeometry(new Point(0, 0));
}
}
Below is my more idiomatically WPF, full-featured take on this. It supports pretty much everything you'd expect, including:
- all font related properties including stretch and style
- text alignment (left, right, center, justify)
- text wrapping
- text trimming
- text decorations (underline, strike through etcetera)
Here's a simple example of what can be achieved with it:
<local:OutlinedTextBlock FontFamily="Verdana" FontSize="20pt" FontWeight="ExtraBold" TextWrapping="Wrap" StrokeThickness="1" Stroke="{StaticResource TextStroke}" Fill="{StaticResource TextFill}">
Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit
</local:OutlinedTextBlock>
Which results in:
Here's the code for the control:
using System;
using System.ComponentModel;
using System.Globalization;
using System.Windows;
using System.Windows.Documents;
using System.Windows.Markup;
using System.Windows.Media;
[ContentProperty("Text")]
public class OutlinedTextBlock : FrameworkElement
{
public static readonly DependencyProperty FillProperty = DependencyProperty.Register(
"Fill",
typeof(Brush),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(Brushes.Black, FrameworkPropertyMetadataOptions.AffectsRender));
public static readonly DependencyProperty StrokeProperty = DependencyProperty.Register(
"Stroke",
typeof(Brush),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(Brushes.Black, FrameworkPropertyMetadataOptions.AffectsRender));
public static readonly DependencyProperty StrokeThicknessProperty = DependencyProperty.Register(
"StrokeThickness",
typeof(double),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(1d, FrameworkPropertyMetadataOptions.AffectsRender));
public static readonly DependencyProperty FontFamilyProperty = TextElement.FontFamilyProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontSizeProperty = TextElement.FontSizeProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontStretchProperty = TextElement.FontStretchProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontStyleProperty = TextElement.FontStyleProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontWeightProperty = TextElement.FontWeightProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextProperty = DependencyProperty.Register(
"Text",
typeof(string),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextInvalidated));
public static readonly DependencyProperty TextAlignmentProperty = DependencyProperty.Register(
"TextAlignment",
typeof(TextAlignment),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextDecorationsProperty = DependencyProperty.Register(
"TextDecorations",
typeof(TextDecorationCollection),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextTrimmingProperty = DependencyProperty.Register(
"TextTrimming",
typeof(TextTrimming),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextWrappingProperty = DependencyProperty.Register(
"TextWrapping",
typeof(TextWrapping),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(TextWrapping.NoWrap, OnFormattedTextUpdated));
private FormattedText formattedText;
private Geometry textGeometry;
public OutlinedTextBlock()
{
this.TextDecorations = new TextDecorationCollection();
}
public Brush Fill
{
get { return (Brush)GetValue(FillProperty); }
set { SetValue(FillProperty, value); }
}
public FontFamily FontFamily
{
get { return (FontFamily)GetValue(FontFamilyProperty); }
set { SetValue(FontFamilyProperty, value); }
}
[TypeConverter(typeof(FontSizeConverter))]
public double FontSize
{
get { return (double)GetValue(FontSizeProperty); }
set { SetValue(FontSizeProperty, value); }
}
public FontStretch FontStretch
{
get { return (FontStretch)GetValue(FontStretchProperty); }
set { SetValue(FontStretchProperty, value); }
}
public FontStyle FontStyle
{
get { return (FontStyle)GetValue(FontStyleProperty); }
set { SetValue(FontStyleProperty, value); }
}
public FontWeight FontWeight
{
get { return (FontWeight)GetValue(FontWeightProperty); }
set { SetValue(FontWeightProperty, value); }
}
public Brush Stroke
{
get { return (Brush)GetValue(StrokeProperty); }
set { SetValue(StrokeProperty, value); }
}
public double StrokeThickness
{
get { return (double)GetValue(StrokeThicknessProperty); }
set { SetValue(StrokeThicknessProperty, value); }
}
public string Text
{
get { return (string)GetValue(TextProperty); }
set { SetValue(TextProperty, value); }
}
public TextAlignment TextAlignment
{
get { return (TextAlignment)GetValue(TextAlignmentProperty); }
set { SetValue(TextAlignmentProperty, value); }
}
public TextDecorationCollection TextDecorations
{
get { return (TextDecorationCollection)this.GetValue(TextDecorationsProperty); }
set { this.SetValue(TextDecorationsProperty, value); }
}
public TextTrimming TextTrimming
{
get { return (TextTrimming)GetValue(TextTrimmingProperty); }
set { SetValue(TextTrimmingProperty, value); }
}
public TextWrapping TextWrapping
{
get { return (TextWrapping)GetValue(TextWrappingProperty); }
set { SetValue(TextWrappingProperty, value); }
}
protected override void OnRender(DrawingContext drawingContext)
{
this.EnsureGeometry();
drawingContext.DrawGeometry(this.Fill, new Pen(this.Stroke, this.StrokeThickness), this.textGeometry);
}
protected override Size MeasureOverride(Size availableSize)
{
this.EnsureFormattedText();
// constrain the formatted text according to the available size
// the Math.Min call is important - without this constraint (which seems arbitrary, but is the maximum allowable text width), things blow up when availableSize is infinite in both directions
// the Math.Max call is to ensure we don't hit zero, which will cause MaxTextHeight to throw
this.formattedText.MaxTextWidth = Math.Min(3579139, availableSize.Width);
this.formattedText.MaxTextHeight = Math.Max(0.0001d, availableSize.Height);
// return the desired size
return new Size(this.formattedText.Width, this.formattedText.Height);
}
protected override Size ArrangeOverride(Size finalSize)
{
this.EnsureFormattedText();
// update the formatted text with the final size
this.formattedText.MaxTextWidth = finalSize.Width;
this.formattedText.MaxTextHeight = finalSize.Height;
// need to re-generate the geometry now that the dimensions have changed
this.textGeometry = null;
return finalSize;
}
private static void OnFormattedTextInvalidated(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
{
var outlinedTextBlock = (OutlinedTextBlock)dependencyObject;
outlinedTextBlock.formattedText = null;
outlinedTextBlock.textGeometry = null;
outlinedTextBlock.InvalidateMeasure();
outlinedTextBlock.InvalidateVisual();
}
private static void OnFormattedTextUpdated(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
{
var outlinedTextBlock = (OutlinedTextBlock)dependencyObject;
outlinedTextBlock.UpdateFormattedText();
outlinedTextBlock.textGeometry = null;
outlinedTextBlock.InvalidateMeasure();
outlinedTextBlock.InvalidateVisual();
}
private void EnsureFormattedText()
{
if (this.formattedText != null || this.Text == null)
{
return;
}
this.formattedText = new FormattedText(
this.Text,
CultureInfo.CurrentUICulture,
this.FlowDirection,
new Typeface(this.FontFamily, this.FontStyle, this.FontWeight, FontStretches.Normal),
this.FontSize,
Brushes.Black);
this.UpdateFormattedText();
}
private void UpdateFormattedText()
{
if (this.formattedText == null)
{
return;
}
this.formattedText.MaxLineCount = this.TextWrapping == TextWrapping.NoWrap ? 1 : int.MaxValue;
this.formattedText.TextAlignment = this.TextAlignment;
this.formattedText.Trimming = this.TextTrimming;
this.formattedText.SetFontSize(this.FontSize);
this.formattedText.SetFontStyle(this.FontStyle);
this.formattedText.SetFontWeight(this.FontWeight);
this.formattedText.SetFontFamily(this.FontFamily);
this.formattedText.SetFontStretch(this.FontStretch);
this.formattedText.SetTextDecorations(this.TextDecorations);
}
private void EnsureGeometry()
{
if (this.textGeometry != null)
{
return;
}
this.EnsureFormattedText();
this.textGeometry = this.formattedText.BuildGeometry(new Point(0, 0));
}
}
I modified @Javier G. answer
Stroke position can be: center, outside or Inside, the default is outside.
Fill can be transparent.
Center:
Outside:
Inside:
Code:
using System;
using System.ComponentModel;
using System.Globalization;
using System.Windows;
using System.Windows.Documents;
using System.Windows.Markup;
using System.Windows.Media;
namespace WpfApp2
{
public enum StrokePosition
{
Center,
Outside,
Inside
}
[ContentProperty("Text")]
public class OutlinedTextBlock : FrameworkElement
{
private void UpdatePen()
{
_Pen = new Pen(Stroke, StrokeThickness)
{
DashCap = PenLineCap.Round,
EndLineCap = PenLineCap.Round,
LineJoin = PenLineJoin.Round,
StartLineCap = PenLineCap.Round
};
if (StrokePosition == StrokePosition.Outside || StrokePosition == StrokePosition.Inside)
{
_Pen.Thickness = StrokeThickness * 2;
}
InvalidateVisual();
}
public StrokePosition StrokePosition
{
get { return (StrokePosition)GetValue(StrokePositionProperty); }
set { SetValue(StrokePositionProperty, value); }
}
public static readonly DependencyProperty StrokePositionProperty =
DependencyProperty.Register("StrokePosition",
typeof(StrokePosition),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(StrokePosition.Outside, FrameworkPropertyMetadataOptions.AffectsRender));
public static readonly DependencyProperty FillProperty = DependencyProperty.Register(
"Fill",
typeof(Brush),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(Brushes.Black, FrameworkPropertyMetadataOptions.AffectsRender));
public static readonly DependencyProperty StrokeProperty = DependencyProperty.Register(
"Stroke",
typeof(Brush),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(Brushes.Black, FrameworkPropertyMetadataOptions.AffectsRender));
public static readonly DependencyProperty StrokeThicknessProperty = DependencyProperty.Register(
"StrokeThickness",
typeof(double),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(1d, FrameworkPropertyMetadataOptions.AffectsRender));
public static readonly DependencyProperty FontFamilyProperty = TextElement.FontFamilyProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontSizeProperty = TextElement.FontSizeProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontStretchProperty = TextElement.FontStretchProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontStyleProperty = TextElement.FontStyleProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty FontWeightProperty = TextElement.FontWeightProperty.AddOwner(
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextProperty = DependencyProperty.Register(
"Text",
typeof(string),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextInvalidated));
public static readonly DependencyProperty TextAlignmentProperty = DependencyProperty.Register(
"TextAlignment",
typeof(TextAlignment),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextDecorationsProperty = DependencyProperty.Register(
"TextDecorations",
typeof(TextDecorationCollection),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextTrimmingProperty = DependencyProperty.Register(
"TextTrimming",
typeof(TextTrimming),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(OnFormattedTextUpdated));
public static readonly DependencyProperty TextWrappingProperty = DependencyProperty.Register(
"TextWrapping",
typeof(TextWrapping),
typeof(OutlinedTextBlock),
new FrameworkPropertyMetadata(TextWrapping.NoWrap, OnFormattedTextUpdated));
private FormattedText _FormattedText;
private Geometry _TextGeometry;
private Pen _Pen;
private PathGeometry _clipGeometry;
public Brush Fill
{
get { return (Brush)GetValue(FillProperty); }
set { SetValue(FillProperty, value); }
}
public FontFamily FontFamily
{
get { return (FontFamily)GetValue(FontFamilyProperty); }
set { SetValue(FontFamilyProperty, value); }
}
[TypeConverter(typeof(FontSizeConverter))]
public double FontSize
{
get { return (double)GetValue(FontSizeProperty); }
set { SetValue(FontSizeProperty, value); }
}
public FontStretch FontStretch
{
get { return (FontStretch)GetValue(FontStretchProperty); }
set { SetValue(FontStretchProperty, value); }
}
public FontStyle FontStyle
{
get { return (FontStyle)GetValue(FontStyleProperty); }
set { SetValue(FontStyleProperty, value); }
}
public FontWeight FontWeight
{
get { return (FontWeight)GetValue(FontWeightProperty); }
set { SetValue(FontWeightProperty, value); }
}
public Brush Stroke
{
get { return (Brush)GetValue(StrokeProperty); }
set { SetValue(StrokeProperty, value); }
}
public double StrokeThickness
{
get { return (double)GetValue(StrokeThicknessProperty); }
set { SetValue(StrokeThicknessProperty, value); }
}
public string Text
{
get { return (string)GetValue(TextProperty); }
set { SetValue(TextProperty, value); }
}
public TextAlignment TextAlignment
{
get { return (TextAlignment)GetValue(TextAlignmentProperty); }
set { SetValue(TextAlignmentProperty, value); }
}
public TextDecorationCollection TextDecorations
{
get { return (TextDecorationCollection)GetValue(TextDecorationsProperty); }
set { SetValue(TextDecorationsProperty, value); }
}
public TextTrimming TextTrimming
{
get { return (TextTrimming)GetValue(TextTrimmingProperty); }
set { SetValue(TextTrimmingProperty, value); }
}
public TextWrapping TextWrapping
{
get { return (TextWrapping)GetValue(TextWrappingProperty); }
set { SetValue(TextWrappingProperty, value); }
}
public OutlinedTextBlock()
{
UpdatePen();
TextDecorations = new TextDecorationCollection();
}
protected override void OnRender(DrawingContext drawingContext)
{
EnsureGeometry();
drawingContext.DrawGeometry(Fill, null, _TextGeometry);
if (StrokePosition == StrokePosition.Outside)
{
drawingContext.PushClip(_clipGeometry);
}
else if (StrokePosition == StrokePosition.Inside)
{
drawingContext.PushClip(_TextGeometry);
}
drawingContext.DrawGeometry(null, _Pen, _TextGeometry);
if (StrokePosition == StrokePosition.Outside || StrokePosition == StrokePosition.Inside)
{
drawingContext.Pop();
}
}
protected override Size MeasureOverride(Size availableSize)
{
EnsureFormattedText();
// constrain the formatted text according to the available size
double w = availableSize.Width;
double h = availableSize.Height;
// the Math.Min call is important - without this constraint (which seems arbitrary, but is the maximum allowable text width), things blow up when availableSize is infinite in both directions
// the Math.Max call is to ensure we don't hit zero, which will cause MaxTextHeight to throw
_FormattedText.MaxTextWidth = Math.Min(3579139, w);
_FormattedText.MaxTextHeight = Math.Max(0.0001d, h);
// return the desired size
return new Size(Math.Ceiling(_FormattedText.Width), Math.Ceiling(_FormattedText.Height));
}
protected override Size ArrangeOverride(Size finalSize)
{
EnsureFormattedText();
// update the formatted text with the final size
_FormattedText.MaxTextWidth = finalSize.Width;
_FormattedText.MaxTextHeight = Math.Max(0.0001d, finalSize.Height);
// need to re-generate the geometry now that the dimensions have changed
_TextGeometry = null;
UpdatePen();
return finalSize;
}
private static void OnFormattedTextInvalidated(DependencyObject dependencyObject,
DependencyPropertyChangedEventArgs e)
{
var outlinedTextBlock = (OutlinedTextBlock)dependencyObject;
outlinedTextBlock._FormattedText = null;
outlinedTextBlock._TextGeometry = null;
outlinedTextBlock.InvalidateMeasure();
outlinedTextBlock.InvalidateVisual();
}
private static void OnFormattedTextUpdated(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
{
var outlinedTextBlock = (OutlinedTextBlock)dependencyObject;
outlinedTextBlock.UpdateFormattedText();
outlinedTextBlock._TextGeometry = null;
outlinedTextBlock.InvalidateMeasure();
outlinedTextBlock.InvalidateVisual();
}
private void EnsureFormattedText()
{
if (_FormattedText != null)
{
return;
}
_FormattedText = new FormattedText(
Text ?? "",
CultureInfo.CurrentUICulture,
FlowDirection,
new Typeface(FontFamily, FontStyle, FontWeight, FontStretch),
FontSize,
Brushes.Black);
UpdateFormattedText();
}
private void UpdateFormattedText()
{
if (_FormattedText == null)
{
return;
}
_FormattedText.MaxLineCount = TextWrapping == TextWrapping.NoWrap ? 1 : int.MaxValue;
_FormattedText.TextAlignment = TextAlignment;
_FormattedText.Trimming = TextTrimming;
_FormattedText.SetFontSize(FontSize);
_FormattedText.SetFontStyle(FontStyle);
_FormattedText.SetFontWeight(FontWeight);
_FormattedText.SetFontFamily(FontFamily);
_FormattedText.SetFontStretch(FontStretch);
_FormattedText.SetTextDecorations(TextDecorations);
}
private void EnsureGeometry()
{
if (_TextGeometry != null)
{
return;
}
EnsureFormattedText();
_TextGeometry = _FormattedText.BuildGeometry(new Point(0, 0));
if (StrokePosition == StrokePosition.Outside)
{
var boundsGeo = new RectangleGeometry(new Rect(0, 0, ActualWidth, ActualHeight));
_clipGeometry = Geometry.Combine(boundsGeo, _TextGeometry, GeometryCombineMode.Exclude, null);
}
}
}
}
Usage:
<Grid Margin="12" Background="Bisque">
<local:OutlinedTextBlock Stroke="Red"
ClipToBounds="False"
FontSize="56"
Fill="Transparent"
StrokePosition="Inside"
StrokeThickness="1" Text=" abc">
</local:OutlinedTextBlock>
</Grid>
Found It. Not so easy to do apparently, there is no built in Stroke text in WPF (kind of a big missing feature if you ask me). First create the custom class:
using System;
using System.Windows.Media;
using System.Globalization;
using System.Windows;
using System.Windows.Markup;
namespace CustomXaml
{
public class OutlinedText : FrameworkElement, IAddChild
{
#region Private Fields
private Geometry _textGeometry;
#endregion
#region Private Methods
/// <summary>
/// Invoked when a dependency property has changed. Generate a new FormattedText object to display.
/// </summary>
/// <param name="d">OutlineText object whose property was updated.</param>
/// <param name="e">Event arguments for the dependency property.</param>
private static void OnOutlineTextInvalidated(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
((OutlinedText)d).CreateText();
}
#endregion
#region FrameworkElement Overrides
/// <summary>
/// OnRender override draws the geometry of the text and optional highlight.
/// </summary>
/// <param name="drawingContext">Drawing context of the OutlineText control.</param>
protected override void OnRender(DrawingContext drawingContext)
{
CreateText();
// Draw the outline based on the properties that are set.
drawingContext.DrawGeometry(Fill, new Pen(Stroke, StrokeThickness), _textGeometry);
}
/// <summary>
/// Create the outline geometry based on the formatted text.
/// </summary>
public void CreateText()
{
FontStyle fontStyle = FontStyles.Normal;
FontWeight fontWeight = FontWeights.Medium;
if (Bold == true) fontWeight = FontWeights.Bold;
if (Italic == true) fontStyle = FontStyles.Italic;
// Create the formatted text based on the properties set.
FormattedText formattedText = new FormattedText(
Text,
CultureInfo.GetCultureInfo("en-us"),
FlowDirection.LeftToRight,
new Typeface(Font, fontStyle, fontWeight, FontStretches.Normal),
FontSize,
Brushes.Black // This brush does not matter since we use the geometry of the text.
);
// Build the geometry object that represents the text.
_textGeometry = formattedText.BuildGeometry(new Point(0, 0));
//set the size of the custome control based on the size of the text
this.MinWidth = formattedText.Width;
this.MinHeight = formattedText.Height;
}
#endregion
#region DependencyProperties
/// <summary>
/// Specifies whether the font should display Bold font weight.
/// </summary>
public bool Bold
{
get
{
return (bool)GetValue(BoldProperty);
}
set
{
SetValue(BoldProperty, value);
}
}
/// <summary>
/// Identifies the Bold dependency property.
/// </summary>
public static readonly DependencyProperty BoldProperty = DependencyProperty.Register(
"Bold",
typeof(bool),
typeof(OutlinedText),
new FrameworkPropertyMetadata(
false,
FrameworkPropertyMetadataOptions.AffectsRender,
new PropertyChangedCallback(OnOutlineTextInvalidated),
null
)
);
/// <summary>
/// Specifies the brush to use for the fill of the formatted text.
/// </summary>
public Brush Fill
{
get
{
return (Brush)GetValue(FillProperty);
}
set
{
SetValue(FillProperty, value);
}
}
/// <summary>
/// Identifies the Fill dependency property.
/// </summary>
public static readonly DependencyProperty FillProperty = DependencyProperty.Register(
"Fill",
typeof(Brush),
typeof(OutlinedText),
new FrameworkPropertyMetadata(
new SolidColorBrush(Colors.LightSteelBlue),
FrameworkPropertyMetadataOptions.AffectsRender,
new PropertyChangedCallback(OnOutlineTextInvalidated),
null
)
);
/// <summary>
/// The font to use for the displayed formatted text.
/// </summary>
public FontFamily Font
{
get
{
return (FontFamily)GetValue(FontProperty);
}
set
{
SetValue(FontProperty, value);
}
}
/// <summary>
/// Identifies the Font dependency property.
/// </summary>
public static readonly DependencyProperty FontProperty = DependencyProperty.Register(
"Font",
typeof(FontFamily),
typeof(OutlinedText),
new FrameworkPropertyMetadata(
new FontFamily("Arial"),
FrameworkPropertyMetadataOptions.AffectsRender,
new PropertyChangedCallback(OnOutlineTextInvalidated),
null
)
);
/// <summary>
/// The current font size.
/// </summary>
public double FontSize
{
get
{
return (double)GetValue(FontSizeProperty);
}
set
{
SetValue(FontSizeProperty, value);
}
}
/// <summary>
/// Identifies the FontSize dependency property.
/// </summary>
public static readonly DependencyProperty FontSizeProperty = DependencyProperty.Register(
"FontSize",
typeof(double),
typeof(OutlinedText),
new FrameworkPropertyMetadata(
(double)48.0,
FrameworkPropertyMetadataOptions.AffectsRender,
new PropertyChangedCallback(OnOutlineTextInvalidated),
null
)
);
/// <summary>
/// Specifies whether the font should display Italic font style.
/// </summary>
public bool Italic
{
get
{
return (bool)GetValue(ItalicProperty);
}
set
{
SetValue(ItalicProperty, value);
}
}
/// <summary>
/// Identifies the Italic dependency property.
/// </summary>
public static readonly DependencyProperty ItalicProperty = DependencyProperty.Register(
"Italic",
typeof(bool),
typeof(OutlinedText),
new FrameworkPropertyMetadata(
false,
FrameworkPropertyMetadataOptions.AffectsRender,
new PropertyChangedCallback(OnOutlineTextInvalidated),
null
)
);
/// <summary>
/// Specifies the brush to use for the stroke and optional hightlight of the formatted text.
/// </summary>
public Brush Stroke
{
get
{
return (Brush)GetValue(StrokeProperty);
}
set
{
SetValue(StrokeProperty, value);
}
}
/// <summary>
/// Identifies the Stroke dependency property.
/// </summary>
public static readonly DependencyProperty StrokeProperty = DependencyProperty.Register(
"Stroke",
typeof(Brush),
typeof(OutlinedText),
new FrameworkPropertyMetadata(
new SolidColorBrush(Colors.Teal),
FrameworkPropertyMetadataOptions.AffectsRender,
new PropertyChangedCallback(OnOutlineTextInvalidated),
null
)
);
/// <summary>
/// The stroke thickness of the font.
/// </summary>
public ushort StrokeThickness
{
get
{
return (ushort)GetValue(StrokeThicknessProperty);
}
set
{
SetValue(StrokeThicknessProperty, value);
}
}
/// <summary>
/// Identifies the StrokeThickness dependency property.
/// </summary>
public static readonly DependencyProperty StrokeThicknessProperty = DependencyProperty.Register(
"StrokeThickness",
typeof(ushort),
typeof(OutlinedText),
new FrameworkPropertyMetadata(
(ushort)0,
FrameworkPropertyMetadataOptions.AffectsRender,
new PropertyChangedCallback(OnOutlineTextInvalidated),
null
)
);
/// <summary>
/// Specifies the text string to display.
/// </summary>
public string Text
{
get
{
return (string)GetValue(TextProperty);
}
set
{
SetValue(TextProperty, value);
}
}
/// <summary>
/// Identifies the Text dependency property.
/// </summary>
public static readonly DependencyProperty TextProperty = DependencyProperty.Register(
"Text",
typeof(string),
typeof(OutlinedText),
new FrameworkPropertyMetadata(
"",
FrameworkPropertyMetadataOptions.AffectsRender,
new PropertyChangedCallback(OnOutlineTextInvalidated),
null
)
);
public void AddChild(Object value)
{
}
public void AddText(string value)
{
Text = value;
}
#endregion
}
}
The you can reference it in your xaml.
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:customControls="clr-namespace:CustomXaml;assembly=CustomXaml">
<Grid>
<customControls:OutlinedText x:Name="TextContent" Fill="#ffffffff" FontSize="28"
Bold="True" Stroke="Black" StrokeThickness="1" Text="Back" Margin="10,0,10,0"
HorizontalAlignment="Center" VerticalAlignment="Center" Height="Auto" Width="Auto" />
</Grid>
</Page>