iphone - 如何以编程方式将图像裁剪成碎片

Question

我需要以编程方式将图像分为 9 block 。关于如何执行此操作有什么建议吗？

Answer 1

下面的代码也是一个检测被点击的图片片段的解决方案。这个想法是获取一个 UIImage 并使用 CGImageCreateWithImageInRect 来裁剪部分。从裁剪的片段中创建一个新的 UIImage 并将其放置在 UIImageView 中。为了让点击手势正常工作，我必须将 UIImageView 放置在 UIView 中。最后，提供手势和唯一标签，以便在点击时可以识别该作品。

- (void)loadView {
    UIView* root = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
    UIImage* whole = [UIImage imageNamed:@"whole.jpg"]; //I know this image is 300x300

    int partId = 0;
    for (int x=0; x<=200; x+=100) {
        for(int y=0; y<=200; y+=100) {
            CGImageRef cgImg = CGImageCreateWithImageInRect(whole.CGImage, CGRectMake(x, y, 100, 100));
            UIImage* part = [UIImage imageWithCGImage:cgImg];
            UIImageView* iv = [[UIImageView alloc] initWithImage:part];

            UIView* sView = [[UIView alloc] initWithFrame:CGRectMake(200-x, 200-y, 100, 100)];
            [sView addSubview:iv];
            [iv release];

            UITapGestureRecognizer* tap = [[UITapGestureRecognizer alloc] initWithTarget:self
                                                                                  action:@selector(tap:)];
            tap.numberOfTapsRequired = 1;
            [sView addGestureRecognizer:tap];
            [tap release];

            sView.tag = partId;

            [root addSubview:sView];
            [sView release];
            partId++;
            CGImageRelease(cgImg);
        }
    }

    self.view = root;
}

- (void)tap:(UITapGestureRecognizer*)gesture
{
    NSLog(@"image tap=%d", gesture.view.tag);
}