135-178_Chap05158 5.4.3 UIImage *4 drawAtPoint:blendMode: alpha: drawInRect:blendMode:alpha: alpha 0.0 1.0 0.0 0.0 blendMode CGBlendMode drawInRect:blendMode:alpha: CGBlendMode 16 5.4-1 // backImage_ UIImage // [backImage_ drawInRect:rect blendMode:kCGBlendModeNormal alpha:1.0]; // frontImage_ UIImage // [frontImage_ drawInRect:rect blendMode: kCGBlendModeDarken alpha:1.0]; Chapter 05 *4 UIImage UIImage s 5.4-1
