ReadWriteBitmapDataExtensionsDrawTextOutlineAsync(IReadWriteBitmapData, Pen, String, SKFont, PointF, DrawingOptions, TaskConfig) Method

Draws the outline of a text with the specified Pen asynchronously.

Definition

Namespace: KGySoft.Drawing.SkiaSharp
Assembly: KGySoft.Drawing.SkiaSharp (in KGySoft.Drawing.SkiaSharp.dll) Version: 10.0.0-rc.1

public static Task<bool> DrawTextOutlineAsync(
	this IReadWriteBitmapData bitmapData,
	Pen pen,
	string text,
	SKFont font,
	PointF location,
	DrawingOptions? drawingOptions = null,
	TaskConfig? asyncConfig = null
)

<ExtensionAttribute>
Public Shared Function DrawTextOutlineAsync ( 
	bitmapData As IReadWriteBitmapData,
	pen As Pen,
	text As String,
	font As SKFont,
	location As PointF,
	Optional drawingOptions As DrawingOptions = Nothing,
	Optional asyncConfig As TaskConfig = Nothing
) As Task(Of Boolean)

C++

public:
[ExtensionAttribute]
static Task<bool>^ DrawTextOutlineAsync(
	IReadWriteBitmapData^ bitmapData, 
	Pen^ pen, 
	String^ text, 
	SKFont^ font, 
	PointF location, 
	DrawingOptions^ drawingOptions = nullptr, 
	TaskConfig^ asyncConfig = nullptr
)

[<ExtensionAttribute>]
static member DrawTextOutlineAsync : 
        bitmapData : IReadWriteBitmapData * 
        pen : Pen * 
        text : string * 
        font : SKFont * 
        location : PointF * 
        ?drawingOptions : DrawingOptions * 
        ?asyncConfig : TaskConfig 
(* Defaults:
        let _drawingOptions = defaultArg drawingOptions null
        let _asyncConfig = defaultArg asyncConfig null
*)
-> Task<bool>

Parameters

bitmapData IReadWriteBitmapData: The IReadWriteBitmapData instance to draw on.
pen Pen: The Pen that determines the characteristics of the text outline.
text String: A string that represents the text to draw.
font SKFont: The SKFont that defines the typeface, size, and style of the text.
location PointF: The location of the upper-left corner of the text, not counting the width of the outline.
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: .
asyncConfig TaskConfig (Optional): The configuration of the asynchronous operation such as parallelization, cancellation, reporting progress, etc. When Progress is set in this parameter, then this library always passes a DrawingOperation instance to the generic methods of the IAsyncProgress interface. This parameter is optional.
Default value: .

Return Value

TaskBoolean
A task that represents the asynchronous operation. Its result is , if the operation completed successfully, or , if the operation has been canceled and the ThrowIfCanceled property in asyncConfig parameter was .

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 DrawTextAsync methods instead.

Tip

To draw a text with both filled and outlined characters, instead of calling DrawTextAsync and DrawTextOutlineAsync consecutively, you can achieve a better performance by creating a Path once, and then calling the FillPathAsync and DrawPathAsync methods. You can convert the specified text to a Path by using the SKFont.GetTextPath and SKPathExtensions.ToPath methods. 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 is not a blocking call even if the MaxDegreeOfParallelism property of the asyncConfig parameter is 1.

Exceptions

ArgumentNullException	bitmapData, pen, text or font is .
OverflowException	The coordinates (after a possible transformation specified in drawingOptions) are outside the bounds of an int value.
TaskCanceledException	The operation has been canceled and the ThrowIfCanceled property in asyncConfig was . This exception is thrown when the result is awaited.