CGLayers为什么不混合?
为什么obj2不与obj1混合,但不使用CGLayer它工作正常,与CGContextDrawLayerAtPoint相同的问题,CGLayer不支持CGContextSetBlendMode?
//Layer
CGContextRef context = UIGraphicsGetCurrentContext();
CGLayerRef objectLayer = CGLayerCreateWithContext (context, rect.size, NULL);
CGContextRef objectContext = CGLayerGetContext (objectLayer);
//obj1
CGContextDrawImage(objectContext, CGRectMake(0, 0, rect.size.width, rect.size.height), [[UIImage imageNamed:@"background.png"] CGImage]);
//obj2
CGContextSetBlendMode(objectContext, kCGBlendModeSoftLight);
CGContextSetAlpha(objectContext, 0.5f);
CGContextDrawImage(objectContext, CGRectMake(0, 0, rect.size.width, rect.size.height), [[UIImage imageNamed:@"overlay1.png"] CGImage]);
CGContextDrawLayerInRect(context, rect, objectLayer);