ReadWriteBitmapDataExtensionsDrawTextOutline(IReadWriteBitmapData, IAsyncContext, Color32, GlyphRun, PointF, DrawingOptions) Method

Draws the one-pixel wide outline of a text represented by a GlyphRun instance with the specified color, using a context that may belong to a higher level, possibly asynchronous operation.

Definition

Namespace: KGySoft.Drawing.Wpf
Assembly: KGySoft.Drawing.Wpf (in KGySoft.Drawing.Wpf.dll) Version: 10.0.0-rc.1
C#
public static bool DrawTextOutline(
	this IReadWriteBitmapData bitmapData,
	IAsyncContext? context,
	Color32 color,
	GlyphRun text,
	PointF offset,
	DrawingOptions? drawingOptions = null
)

Parameters

bitmapData  IReadWriteBitmapData
The IReadWriteBitmapData instance to draw on.
context  IAsyncContext
An IAsyncContext instance that contains information for asynchronous processing about the current operation.
color  Color32
The color of the text outline to draw.
text  GlyphRun
A GlyphRun instance representing the text to draw.
offset  PointF
The offset to be applied to the BaselineOrigin of text.
drawingOptions  DrawingOptions  (Optional)
A DrawingOptions instance that specifies the drawing options to use. If , then the default options are used. This parameter is optional.
Default value: .

Return Value

Boolean
, if the operation completed successfully.
, if the operation has been canceled.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IReadWriteBitmapData. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Remarks

This method draws only the outline of a text. To draw a text with filled characters, use the DrawText methods instead.

  Tip

To draw a text with both filled and outlined characters, instead of calling DrawText and DrawTextOutline consecutively, you can achieve a better performance by creating a Path once, and then calling the FillPath and DrawPath methods. You can convert the specified text to a Path by obtaining a Geometry instance by calling the GlyphRun.BuildGeometry method, and then using the ToPath extension method. If you draw the text without antialiasing, it is recommended to set the FastThinLines to in drawingOptions so the outline correctly aligns to the filled area.

When AntiAliasing is set in drawingOptions and you use non-monochromatic colors, it is recommended to specify Linear color space when you obtain the IReadWriteBitmapData instance, especially for small fonts; otherwise, the quality of the drawn text can be poor if alpha colors are blended in the sRGB color space. See more details at the Examples section of the WorkingColorSpace enumeration.

This method blocks the caller thread but if context belongs to an async top level method, then the execution may already run on a pool thread. Degree of parallelism, the ability of cancellation and reporting progress depend on how these were configured at the top level method. To reconfigure the degree of parallelism of an existing context, you can use the AsyncContextWrapper class.

Alternatively, you can use this method to specify the degree of parallelism for synchronous execution. For example, by passing AsyncHelper.SingleThreadContext to the context parameter the method will be forced to use a single thread only.

When reporting progress, this library always passes a DrawingOperation instance to the generic methods of the IAsyncProgress interface.

  Tip

See the Examples section of the AsyncHelper class for details about how to create a context for possibly async top level methods.

Exceptions

ArgumentNullExceptionbitmapData or text is .
OverflowExceptionThe coordinates (after a possible transformation specified in drawingOptions) are outside the bounds of an int value.

See Also