Graphics.DrawImage Method (Image, Rectangle, Single, Single, Single, Single, GraphicsUnit, ImageAttributes, Graphics.DrawImageAbort)
Draws the specified portion of the specified Image at the specified location and with the specified size.
Assembly: System.Drawing (in System.Drawing.dll)
member DrawImage : image:Image * destRect:Rectangle * srcX:float32 * srcY:float32 * srcWidth:float32 * srcHeight:float32 * srcUnit:GraphicsUnit * imageAttrs:ImageAttributes * callback:Graphics.DrawImageAbort -> unit
Rectangle structure that specifies the location and size of the drawn image. The image is scaled to fit the rectangle.
The x-coordinate of the upper-left corner of the portion of the source image to draw.
The y-coordinate of the upper-left corner of the portion of the source image to draw.
Width of the portion of the source image to draw.
Height of the portion of the source image to draw.
Member of the GraphicsUnit enumeration that specifies the units of measure used to determine the source rectangle.
ImageAttributes that specifies recoloring and gamma information for the image object.
The srcX, srcY, srcWidth, and srcHeight parameters specify a rectangular portion, of the image object to draw. The rectangle is relative to the upper-left corner of the source image. This portion is scaled to fit inside the rectangle specified by the destRect parameter.
This overload with the callback parameter provides the means to stop the drawing of an image once it starts according to criteria determined by the application. For example, an application could start drawing a large image and the user might scroll the image off the screen, in which case the application could stop the drawing.
The following code example is designed for use with Windows Forms, and it requires PaintEventArgse, which is a parameter of the Paint event handler. The code first defines a callback method for the Graphics.DrawImageAbort delegate; the definition is simplistic and merely tests to see whether the method calls it with a null callBackData parameter. The main body of the example performs the following actions:
Creates an instance of the Graphics.DrawImageAbort callback method.
Creates an image from a JPEG file SampImag.jpg in the folder of the example.
Creates points that define a destination rectangle in which to draw the image.
Creates a source rectangle to select the portion of the image to draw.
Sets the graphics drawing unit to pixel.
Draws the original image to the screen.
Creates an additional destination rectangle in which to draw an adjusted image.
Creates and sets the attributes of the adjusted image to have a larger-than-usual gamma value.
Draws the adjusted image to the screen.
For the original, unadjusted destination rectangle, the position locates the image on the screen, and the size of the source rectangle and the size and shape of the destination rectangle determines the scaling of the drawn image.
Because this example uses an overload that does not pass a callBackData parameter, the Graphics.DrawImageAbort callback returns true, which causes the method to end, and the exception-handling code included in the example prints out the exception text rather than drawing the image.
Available since 1.1