图像无响应双击缩放
我的UIImage没有使用以下代码进行缩放。 然后识别轻敲，但缩放不起作用。 它基本上是来自iOS开发站点的taptozoom代码，其中一个导航控制器浮动在UIScrollView和UIImageView后面。 此TapToZoom代码无需导航控制器即可运行。 图像拉伸是否有问题，以允许顶部的导航栏？
#import "Map.h" #define ZOOM_VIEW_TAG 100 #define ZOOM_STEP 1.5 @interface Map (UtilityMethods) - (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center; @end @implementation Map @synthesize imageScrollView, imageView; - (void)loadView { //imageScrollView.userInteractionEnabled = YES; // [self.imageView setUserInteractionEnabled:YES]; //[self.imageView setMultipleTouchEnabled:YES]; NSLog(@"beginning of loadView in map.m"); [super loadView]; // set the tag for the image view [imageView setTag:ZOOM_VIEW_TAG]; //imageScrollView.scrollEnabled = NO; // add gesture recognizers to the image view 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]; [imageView addGestureRecognizer:singleTap]; //added self to fix subview [imageView addGestureRecognizer:doubleTap]; [imageView addGestureRecognizer:twoFingerTap]; [singleTap release]; [doubleTap release]; [twoFingerTap release]; // calculate minimum scale to perfectly fit image width, and begin at that scale float minimumScale = [imageScrollView frame].size.width / [imageView frame].size.width; [imageScrollView setMinimumZoomScale:minimumScale]; [imageScrollView setZoomScale:minimumScale]; } - (void)viewDidUnload { self.imageScrollView = nil; self.imageView = nil; } - (void)dealloc { [imageScrollView release]; [imageView release]; [super dealloc]; } #pragma mark UIScrollViewDelegate methods - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView { return [imageScrollView viewWithTag:ZOOM_VIEW_TAG]; } /************************************** NOTE **************************************/ /* The following delegate method works around a known bug in zoomToRect:animated: */ /* In the next release after 3.0 this workaround will no longer be necessary */ /**********************************************************************************/ - (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale { [scrollView setZoomScale:scale+0.01 animated:NO]; [scrollView setZoomScale:scale animated:NO]; } #pragma mark TapDetectingImageViewDelegate methods - (void)handleSingleTap:(UIGestureRecognizer *)gestureRecognizer { // single tap does nothing for now NSLog(@"single tap detected"); } - (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer { // double tap zooms in NSLog(@"beginning handleDoubleTap to zoom"); float newScale = [imageScrollView zoomScale] * ZOOM_STEP; CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]]; [imageScrollView zoomToRect:zoomRect animated:YES]; } - (void)handleTwoFingerTap:(UIGestureRecognizer *)gestureRecognizer { // two-finger tap zooms out float newScale = [imageScrollView zoomScale] / ZOOM_STEP; CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]]; [imageScrollView zoomToRect:zoomRect animated:YES]; } #pragma mark UIScroll Subview #pragma mark Utility methods - (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center { CGRect zoomRect; NSLog(@"zoomRectForScale"); // the zoom rect is in the content view's coordinates. // At a zoom scale of 1.0, it would be the size of the imageScrollView's bounds. // As the zoom scale decreases, so more content is visible, the size of the rect grows. zoomRect.size.height = [imageScrollView frame].size.height / scale; zoomRect.size.width = [imageScrollView frame].size.width / scale; // choose an origin so as to get the right center. zoomRect.origin.x = center.x - (zoomRect.size.width / 2.0); zoomRect.origin.y = center.y - (zoomRect.size.height / 2.0); NSLog(@"end of zoom rect"); return zoomRect; } @end 默认情况下，ImageViews默认不响应用户交互，你必须设置它：
imageView.userInteractionEnabled = YES;
你需要确保单击识别器等待双击失败。
[singleTap requireGestureRecognizerToFail:doubleTap];
必须重写-loadView才能初始化self.view – 没有别的。 因为我看不到初始化你的self.view的代码我假设你的视图来自一个nib文件，因此你不能覆盖-loadView方法，或者如果超类负责这个初始化，你不必覆盖它并调用[super loadView] ，但你放在那里的代码完全在错误的地方。 将所有逻辑移到viewDidLoad除了以下行：
// calculate minimum scale to perfectly fit image width, and begin at that scale float minimumScale = [imageScrollView frame].size.width / [imageView frame].size.width; [imageScrollView setMinimumZoomScale:minimumScale]; [imageScrollView setZoomScale:minimumScale];
这些放在viewWillAppear: ，因为这是已正确设置视图层次结构几何的位置，并且您可以拥有准确的frame属性。
导入“RootViewController.h”
定义ZOOM_VIEW_TAG 100
定义ZOOM_STEP 1.5
@interface RootViewController（UtilityMethods） – （CGRect）zoomRectForScale 🙁 float）scale withCenter：（CGPoint）center; @结束
@implementation RootViewController
@synthesize imageScrollView，imageView，mySlider;
-
（IBAction）sliderValueChanged：（UISlider *）sender {mySlider.value = [NSString stringWithFormat：imageScrollView。[sender value]];
//mySlider.value = [NSString stringWithFormat：@“％。1f”，[发送者值]];
//myTextField.text = [NSString stringWithFormat：@“％。1f”，[发送者值]]; }
-
（void）loadView {[super loadView];
//设置图像视图的标签[imageView setTag：ZOOM_VIEW_TAG];
//向图像视图添加手势识别器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];
[imageView addGestureRecognizer：singleTap]; [imageView addGestureRecognizer：doubleTap]; [imageView addGestureRecognizer：twoFingerTap];
[singleTap发布]; [doubleTap发布]; [twoFingerTap发布];
//计算最小比例以完全适合图像宽度，并从该比例开始float minimumScale = [imageScrollView frame] .size.width / [imageView frame] .size.width; [imageScrollView setMinimumZoomScale：minimumScale]; [imageScrollView setZoomScale：minimumScale]; }
-
（void）viewDidUnload {self.imageScrollView = nil; self.imageView = nil; }
-
（void）dealloc {[imageScrollView release]; [imageView发布]; [super dealloc]; }
编译指示标记UIScrollViewDelegate方法
- （UIView *）viewForZoomingInScrollView：（UIScrollView *）scrollView {return [imageScrollView viewWithTag：ZOOM_VIEW_TAG]; }
/ * ** * ** * ** * ** * ** * ** * *注* ** * ** * ** * ** * ** * ** * * / / *以下委托方法有效围绕zoomToRect中的已知错误：动画： / /在3.0之后的下一个版本中，将不再需要此解决方法/ / ** * ** * ** * ** * ** * ** * ** * ** * ** * ** * ** * ** * ** * ** * ** * / – （void）scrollViewDidEndZooming：（UIScrollView *）scrollView withView：（UIView *）view atScale：（float）scale {[ scrollView setZoomScale：scale + 0.01 animated：NO]; [scrollView setZoomScale：scale animated：NO]; }
pragma标记TapDetectingImageViewDelegate方法
-
（void）handleSingleTap：（UIGestureRecognizer *）gestureRecognizer {//单击现在什么都不做}
-
（void）handleDoubleTap：（UIGestureRecognizer *）gestureRecognizer {//双击放大浮动newScale = [imageScrollView zoomScale] * ZOOM_STEP; CGRect zoomRect = [self zoomRectForScale：newScale withCenter：[gestureRecognizer locationInView：gestureRecognizer.view]]; [imageScrollView zoomToRect：zoomRect animated：YES]; }
-
（void）handleTwoFingerTap：（UIGestureRecognizer *）gestureRecognizer {//双指点击缩小浮动newScale = [imageScrollView zoomScale] / ZOOM_STEP; CGRect zoomRect = [self zoomRectForScale：newScale withCenter：[gestureRecognizer locationInView：gestureRecognizer.view]]; [imageScrollView zoomToRect：zoomRect animated：YES]; }
pragma mark实用方法
-
（CGRect）zoomRectForScale 🙁 float）scale withCenter：（CGPoint）center {
CGRect zoomRect;
//缩放矩形位于内容视图的坐标中。 //在缩放比例为1.0时，它将是imageScrollView边界的大小。 //随着缩放比例的减小，可见的内容越多，矩形的大小就越大。 zoomRect.size.height = [imageScrollView frame] .size.height / scale; zoomRect.size.width = [imageScrollView frame] .size.width / scale;
//选择原点以获得正确的中心。 zoomRect.origin.x = center.x – （zoomRect.size.width / 2.0）; zoomRect.origin.y = center.y – （zoomRect.size.height / 2.0）;
return zoomRect; }
@结束