public void FillRectangle(
	Rect rect,
	ICanvasBrush brush,
	ICanvasBrush opacityBrush
)

Parameters

rect

Type: Windows.FoundationRect

brush

Type: Microsoft.Graphics.Canvas.BrushesICanvasBrush

opacityBrush

Type: Microsoft.Graphics.Canvas.BrushesICanvasBrush

Transparent portions of the opacity mask brush indicate the areas where the contents of the rectangle will be transparent, while opaque portions of the mask indicate where the rectangle is visible. The RGB color of the opacity mask is ignored.

For more flexible opacity mask options, see the CreateLayer Overload and CanvasActiveLayer.

Optimization note - this method is fastest when all the following requirements are satisfied:

• The opacity brush is a CanvasImageBrush
• Opacity brush Image is a CanvasBitmap or CanvasRenderTarget
• Opacity brush Transform contains only positive scaling and translation (no rotation or other transforms), and is positioned so the rectangle being drawn will not extend past the edge of the opacity bitmap
• Opacity brush Opacity is set to 1.0 (the default)
• Opacity brush Interpolation is Linear (the default)
• The drawing session Antialiasing property is set to Aliased (not its default!)

The opacity mask brush is allowed to be null.

Reference