如何在 iPhone 中放大图像的选定区域？答案

【问题标题】：How to zoom into a selected area of image in iPhone?如何在 iPhone 中放大图像的选定区域？
【发布时间】：2013-09-18 23:50:53
【问题描述】：

单击该图像视图时，我有一个 ImageView，应创建透明圆圈，再次双击该圆圈时，应缩放该圆圈区域中的特定图像。任何建议将不胜感激。

【问题讨论】：

请修改您的问题并将其分成句子。我不明白你在说什么。
如何在 ImageView 的特定区域放大，用户双击...？任何人都可以建议我...

标签： iphone objective-c uiimageview uiimage zooming

【解决方案1】：

我认为这段代码会对你有所帮助

- (id)initWithImage:(UIImage *)image {
    self = [super initWithImage:image];
    if (self) {
        [self setUserInteractionEnabled:YES];

        UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
        UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleDoubleTap:)];
        UITapGestureRecognizer *twoFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTwoFingerTap:)];

        [doubleTap setNumberOfTapsRequired:2];
        [twoFingerTap setNumberOfTouchesRequired:2];

        [self addGestureRecognizer:singleTap];
        [self addGestureRecognizer:doubleTap];
        [self addGestureRecognizer:twoFingerTap];

        [singleTap release];
        [doubleTap release];
        [twoFingerTap release];
    }
    return self;
}

#pragma mark Private

- (void)handleSingleTap:(UIGestureRecognizer *)gestureRecognizer {
    if ([delegate respondsToSelector:@selector(tapDetectingImageView:gotSingleTapAtPoint:)])
        [delegate tapDetectingImageView:self gotSingleTapAtPoint:[gestureRecognizer locationInView:self]];
}

- (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer {
    if ([delegate respondsToSelector:@selector(tapDetectingImageView:gotDoubleTapAtPoint:)])
        [delegate tapDetectingImageView:self gotDoubleTapAtPoint:[gestureRecognizer locationInView:self]];
}

- (void)handleTwoFingerTap:(UIGestureRecognizer *)gestureRecognizer {
    if ([delegate respondsToSelector:@selector(tapDetectingImageView:gotTwoFingerTapAtPoint:)])
        [delegate tapDetectingImageView:self gotTwoFingerTapAtPoint:[gestureRecognizer locationInView:self]];
}

【讨论】：