setAlpha(_:)

Declaration

func setAlpha(_ alpha: CGFloat)

Parameters

• alpha:

  A value that specifies the opacity level. Values can range from 0.0 (transparent) to 1.0 (opaque). Values outside this range are clipped to 0.0 or 1.0.

Discussion

This function sets the alpha value parameter for the specified graphics context. To clear the contents of the drawing canvas, use clear(_:).

See Also

Setting Fill, Stroke, and Shadow Colors

• setFillColor(_:)
• setFillColor(_:)
• setFillColor(cyan:magenta:yellow:black:alpha:)
• setFillColor(gray:alpha:)
• setFillColor(red:green:blue:alpha:)
• setFillColorSpace(_:)
• setShadow(offset:blur:)
• setShadow(offset:blur:color:)
• setStrokeColor(_:)
• setStrokeColor(_:)
• setStrokeColor(cyan:magenta:yellow:black:alpha:)
• setStrokeColor(gray:alpha:)
• setStrokeColor(red:green:blue:alpha:)
• setStrokeColorSpace(_:)
• setStrokePattern(_:colorComponents:)