相关疑难解决方法(0)

我正在使用以下代码为我的UIImage添加圆角,但问题是圆角显示"白色"区域而不是透明或"清晰".我在这做错了什么:

- (UIImage *)makeRoundCornerImageWithCornerWidth:(int)cornerWidth cornerHeight:(int)cornerHeight {
    UIImage * newImage = nil;

    if (self != nil)    {
        NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
        int w = self.size.width;
        int h = self.size.height;

        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
        CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);

        CGContextBeginPath(context);
        CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
        [self addRoundedRectToPath:context rect:rect width:cornerWidth height:cornerHeight];

        CGContextClosePath(context);
        CGContextClip(context);

        CGContextDrawImage(context, CGRectMake(0, 0, w, h), self.CGImage);
        CGImageRef imageMasked = CGBitmapContextCreateImage(context);
        CGContextRelease(context);
        CGColorSpaceRelease(colorSpace);

        newImage = [[UIImage imageWithCGImage:imageMasked] retain];
        CGImageRelease(imageMasked); …