BitmapDataExtensionsBeginDrawPolygon(IReadWriteBitmapData, Pen, IEnumerablePointF, DrawingOptions, AsyncConfig) Method

public static IAsyncResult BeginDrawPolygon(
	this IReadWriteBitmapData bitmapData,
	Pen pen,
	IEnumerable<PointF> points,
	DrawingOptions? drawingOptions = null,
	AsyncConfig? asyncConfig = null
)

<ExtensionAttribute>
Public Shared Function BeginDrawPolygon ( 
	bitmapData As IReadWriteBitmapData,
	pen As Pen,
	points As IEnumerable(Of PointF),
	Optional drawingOptions As DrawingOptions = Nothing,
	Optional asyncConfig As AsyncConfig = Nothing
) As IAsyncResult

public:
[ExtensionAttribute]
static IAsyncResult^ BeginDrawPolygon(
	IReadWriteBitmapData^ bitmapData, 
	Pen^ pen, 
	IEnumerable<PointF>^ points, 
	DrawingOptions^ drawingOptions = nullptr, 
	AsyncConfig^ asyncConfig = nullptr
)

[<ExtensionAttribute>]
static member BeginDrawPolygon : 
        bitmapData : IReadWriteBitmapData * 
        pen : Pen * 
        points : IEnumerable<PointF> * 
        ?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 polygon.

points  IEnumerablePointF

The vertices of the polygon 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  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

Every pair of two consecutive points specifies a side of the polygon. In addition, if the last point and the first point do not coincide, they specify the last side of the polygon.

This method tries to use a shortcut to draw the polygon directly, which is faster than creating a Path and adding the points 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 polygon 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 DrawPolygonAsync methods.

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

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

If the polygon 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