BitmapDataExtensionsBeginDrawLine(IReadWriteBitmapData, Pen, Point, Point, DrawingOptions, AsyncConfig) Method

public static IAsyncResult BeginDrawLine(
	this IReadWriteBitmapData bitmapData,
	Pen pen,
	Point p1,
	Point p2,
	DrawingOptions? drawingOptions = null,
	AsyncConfig? asyncConfig = null
)

<ExtensionAttribute>
Public Shared Function BeginDrawLine ( 
	bitmapData As IReadWriteBitmapData,
	pen As Pen,
	p1 As Point,
	p2 As Point,
	Optional drawingOptions As DrawingOptions = Nothing,
	Optional asyncConfig As AsyncConfig = Nothing
) As IAsyncResult

public:
[ExtensionAttribute]
static IAsyncResult^ BeginDrawLine(
	IReadWriteBitmapData^ bitmapData, 
	Pen^ pen, 
	Point p1, 
	Point p2, 
	DrawingOptions^ drawingOptions = nullptr, 
	AsyncConfig^ asyncConfig = nullptr
)

[<ExtensionAttribute>]
static member BeginDrawLine : 
        bitmapData : IReadWriteBitmapData * 
        pen : Pen * 
        p1 : Point * 
        p2 : Point * 
        ?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 line.

p1  Point

The starting point of the line.

p2  Point

The end point of the line.

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

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

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

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

If the line 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