BitmapDataExtensionsDrawRectangleAsync(IReadWriteBitmapData, Pen, RectangleF, DrawingOptions, TaskConfig) Method

Draws a rectangle with the specified Pen asynchronously.

Definition

Namespace: KGySoft.Drawing.Shapes
Assembly: KGySoft.Drawing.Core (in KGySoft.Drawing.Core.dll) Version: 9.1.1
C#
public static Task<bool> DrawRectangleAsync(
	this IReadWriteBitmapData bitmapData,
	Pen pen,
	RectangleF rectangle,
	DrawingOptions? drawingOptions = null,
	TaskConfig? asyncConfig = null
)

Parameters

bitmapData  IReadWriteBitmapData
The IReadWriteBitmapData instance to draw on.
pen  Pen
The Pen that determines the characteristics of the rectangle.
rectangle  RectangleF
The rectangle to draw.
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 tries to use a shortcut to draw the rectangle directly, which is faster than creating a Path and adding the rectangle to it. A shortcut is possible when the specified pen has a width between 0.25 and 1, it uses a solid Brush with an opaque color, and if drawingOptions is either , or its FastThinLines is enabled in drawingOptions, it specifies that no anti-aliasing and no alpha blending is required, the transformation is the identity matrix, and neither Quantizer nor Ditherer is specified.

When no shortcut can be used and the same rectangle is drawn repeatedly, creating a Path with PreferCaching enabled can provide a better performance.

This method is not a blocking call even if the MaxDegreeOfParallelism property of the asyncConfig parameter is 1.

If the rectangle is drawn by using a shortcut, then the operation is executed synchronously, it cannot be canceled, it is not parallelized, and there is no progress reporting, regardless of the asyncConfig parameter.

Exceptions

ArgumentNullExceptionbitmapData or pen is .
OverflowExceptionThe coordinates (after a possible transformation specified in drawingOptions) are outside the bounds of an int value.
TaskCanceledExceptionThe operation has been canceled and the ThrowIfCanceled property in asyncConfig was . This exception is thrown when the result is awaited.

See Also