BitmapDataExtensionsBeginDrawEllipse(IReadWriteBitmapData, Color32, RectangleF, DrawingOptions, AsyncConfig) Method

public static IAsyncResult BeginDrawEllipse(
	this IReadWriteBitmapData bitmapData,
	Color32 color,
	RectangleF bounds,
	DrawingOptions? drawingOptions = null,
	AsyncConfig? asyncConfig = null
)

<ExtensionAttribute>
Public Shared Function BeginDrawEllipse ( 
	bitmapData As IReadWriteBitmapData,
	color As Color32,
	bounds As RectangleF,
	Optional drawingOptions As DrawingOptions = Nothing,
	Optional asyncConfig As AsyncConfig = Nothing
) As IAsyncResult

public:
[ExtensionAttribute]
static IAsyncResult^ BeginDrawEllipse(
	IReadWriteBitmapData^ bitmapData, 
	Color32 color, 
	RectangleF bounds, 
	DrawingOptions^ drawingOptions = nullptr, 
	AsyncConfig^ asyncConfig = nullptr
)

[<ExtensionAttribute>]
static member BeginDrawEllipse : 
        bitmapData : IReadWriteBitmapData * 
        color : Color32 * 
        bounds : RectangleF * 
        ?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.

color  Color32

The color of the ellipse to draw.

bounds  RectangleF

The bounding rectangle that defines the ellipse.

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

When drawing a one-pixel wide ellipse, the right/bottom values of the bounding rectangle are inclusive, so if the width and height are zero, a single pixel will be drawn.

This method tries to use a shortcut to draw the ellipse directly, which is faster than creating a Path and adding the ellipse to it. A shortcut is possible when drawingOptions is and the specified color is opaque, or when FastThinLines is enabled in drawingOptions, and 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 ellipse 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 DrawEllipseAsync methods.

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

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

If the ellipse 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