BitmapDataExtensionsBeginDrawRoundedRectangle(IReadWriteBitmapData, Pen, Rectangle, Int32, DrawingOptions, AsyncConfig) Method

public static IAsyncResult BeginDrawRoundedRectangle(
	this IReadWriteBitmapData bitmapData,
	Pen pen,
	Rectangle bounds,
	int cornerRadius,
	DrawingOptions? drawingOptions = null,
	AsyncConfig? asyncConfig = null
)

<ExtensionAttribute>
Public Shared Function BeginDrawRoundedRectangle ( 
	bitmapData As IReadWriteBitmapData,
	pen As Pen,
	bounds As Rectangle,
	cornerRadius As Integer,
	Optional drawingOptions As DrawingOptions = Nothing,
	Optional asyncConfig As AsyncConfig = Nothing
) As IAsyncResult

public:
[ExtensionAttribute]
static IAsyncResult^ BeginDrawRoundedRectangle(
	IReadWriteBitmapData^ bitmapData, 
	Pen^ pen, 
	Rectangle bounds, 
	int cornerRadius, 
	DrawingOptions^ drawingOptions = nullptr, 
	AsyncConfig^ asyncConfig = nullptr
)

[<ExtensionAttribute>]
static member BeginDrawRoundedRectangle : 
        bitmapData : IReadWriteBitmapData * 
        pen : Pen * 
        bounds : Rectangle * 
        cornerRadius : int * 
        ?drawingOptions : DrawingOptions * 
        ?asyncConfig : AsyncConfig 
(* Defaults:
        let _drawingOptions = defaultArg drawingOptions null
        let _asyncConfig = defaultArg asyncConfig null
*)
-> IAsyncResult 

Parameters

bitmapData  IReadWriteBitmapData

The IReadWriteBitmapData instance to draw on.

pen  Pen

The Pen that determines the characteristics of the rounded rectangle.

bounds  Rectangle

The bounding rectangle that defines the rounded rectangle.

cornerRadius  Int32

The size of the corner radius of the rounded rectangle for all corners.

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  AsyncConfig  (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

Usage Note

If cornerRadius is negative, the absolute value will be used. If it is greater than the half of the smaller side of the bounding rectangle, it will be adjusted to the half of the smaller side, so the result will be an oval shape. If the cornerRadius is 0, a simple rectangle will be drawn.

This method tries to use a shortcut to draw the rounded rectangle directly, which is faster than creating a Path and adding the rounded 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 rounded rectangle is drawn repeatedly, creating a Path with PreferCaching enabled can provide a better performance.

In .NET Framework 4.0 and above you can use also the DrawRoundedRectangleAsync methods.

To finish the operation and to get the exception that occurred during the operation you have to call the EndDrawRoundedRectangle method.

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

If the rounded 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.

Reference