Instance Property インスタンスプロパティ

isOpaque

A Boolean that indicates whether the canvas is fully opaque.

Declaration 宣言 

var isOpaque: Bool { get set }

Discussion 議論

You might be able to improve performance by setting this value to true, making the canvas is fully opaque. However, in that case, the result of drawing a non-opaque image into the canvas is undefined.

See Also 参照

Managing Opacity and Color

var colorMode: ColorRenderingMode
The working color space and storage format of the canvas.