ios - 如何删除UIImage背景颜色并使之透明？

Question

我想删除UIImage背景色并使其透明...

我试过了，但是下面的代码只是将白色背景颜色更改为黑色。

   UIImage* createColorMaskedImage(UIImage* originalImage){
float maskingColors[6] = {0xEE, 0xFF, 0xEE, 0xFF, 0xEE, 0xFF};
CGImageRef maskedImageRef = CGImageCreateWithMaskingColors(originalImage.CGImage,     maskingColors);
UIImage* maskedImage = [UIImage imageWithCGImage:maskedImageRef];
CGImageRelease(maskedImageRef);
return maskedImage;
}


UIImage *watchImage = [UIImage imageNamed:@"watch2.jpg"];
// Mask image
colorMaskImage_ = createColorMaskedImage(watchImage);
//create image view and set its poistion.
UIImageView* maskImageView = [[UIImageView alloc] initWithImage:colorMaskImage_];
CGRect frame = maskImageView.frame;
frame.origin = CGPointMake(80,60);
maskImageView.frame = frame;
maskImageView.backgroundColor = [UIColor clearColor];
[self.view addSubview:maskImageView];
[maskImageView release];

Answer 1

您的watch2.jpg可能没有alpha值，这会使它具有透明区域。