iphone - UIPinchGestureRecognizer 用于在 xcode 中缩放和平移图像
<p><p>我创建了一个应用程序，其中有一个包含 ImageView 的 View 。
下面使用 UIPinchGestureRecognizer 缩放图像的代码正在工作。
这里 innerview 是我的 View 的名称。</p>
<pre><code> - (void)viewDidLoad
{
;
//Zoom Photo
UIPinchGestureRecognizer *pinchGesture = [ initWithTarget:self action:@selector(handlePinch:)];
;
;
mCurrentScale = 0;
mLastScale = 0;
}
-(void)handlePinch:(UIPinchGestureRecognizer*)sender {
NSLog(@"latscale = %f",mLastScale);
mCurrentScale += - mLastScale;
mLastScale = ;
if (sender.state == UIGestureRecognizerStateEnded)
{
mLastScale = 1.0;
}
CGAffineTransform currentTransform = CGAffineTransformIdentity;
CGAffineTransform newTransform = CGAffineTransformScale(currentTransform,mCurrentScale, mCurrentScale);
innerview.transform = newTransform;
}
</code></pre>
<p>但是如何使用 ScrollView 来正确查看图像呢？</p></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>在 ScrollView 中嵌入你的 innerView
完成捏合后，您可以获取新图像的大小，然后设置其内容大小</p>
<pre><code>-(void)scale:(id)sender {
if([(UIPinchGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {
lastScale = 1.0;
CGSize zoomViewSize = CGSizeApplyAffineTransform(imgScrollView.frame.size, [(UIPinchGestureRecognizer *)sender view].transform);
CGPoint centerPoint = CGPointApplyAffineTransform(imgScrollView.frame.origin, [(UIPinchGestureRecognizer *)sender view].transform);
CGRect r = imgScrollView.bounds;
CGSize scrollViewSize = imgScrollView.frame.size;
imgScrollView.contentSize = zoomViewSize;
imgScrollView.contentOffset = centerPoint;
}
CGFloat currentScale = [[[(UIPinchGestureRecognizer*)sender view].layer valueForKeyPath:@"transform.scale"] floatValue];
CGFloat scale = 1.0 - (lastScale - [(UIPinchGestureRecognizer*)sender scale]);
scale = MIN(scale, imgScrollView.maximumZoomScale / currentScale);
scale = MAX(scale, imgScrollView.minimumZoomScale / currentScale);
CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, scale, scale);
[[(UIPinchGestureRecognizer*)sender view] setTransform:newTransform];
lastScale = [(UIPinchGestureRecognizer*)sender scale];
}
</code></pre>
<p>希望对你有帮助:) </p></p>
<p style="font-size: 20px;">关于iphone - UIPinchGestureRecognizer 用于在 xcode 中缩放和平移图像，我们在Stack Overflow上找到一个类似的问题：
<a href="https://stackoverflow.com/questions/9954582/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/9954582/
</a>
</p>
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