项目中要求对UIImageView进行放大和拖动，所以记录一下。
@interface PutQuestionToViewController ()\
@property (nonatomic, strong) UIImageView *maxImageView;
/** 记录大图的原始尺寸 */
@property (nonatomic, assign) CGRect oldFrame;
/** 大图的最大放大尺寸 */
@property (nonatomic, assign) CGRect largeFrame;
@end
@implementation PutQuestionToViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
// 添加图片
self.maxImageView.image = [UIImage imageNamed:@"picture"];
}
//MARK: 大图maxImageView
- (UIImageView *)maxImageView {
if (!_maxImageView) {
_maxImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 64, SCREENSIZE.width, SCREENSIZE.height - 64)];
_oldFrame = _maxImageView.frame;// 记录原始尺寸
_largeFrame = CGRectMake(0 - SCREENSIZE.width, 0 - SCREENSIZE.height, 3 * _oldFrame.size.width, 3 * _oldFrame.size.height);// 制定最大放大尺寸////
// 允许imageView响应用户操作(切记要让ImageView响应用户操作)
_maxImageView.userInteractionEnabled = YES;
// 添加点击手势
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(maxImageViewTap)];
tap.numberOfTapsRequired = 1;// 点击次数
tap.numberOfTouchesRequired = 1;// 几个手指
[_maxImageView addGestureRecognizer:tap];
// 添加缩放手势
UIPinchGestureRecognizer *pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchView:)];
[_maxImageView addGestureRecognizer:pinchGestureRecognizer];
// 添加移动手势
UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panView:)];
[_maxImageView addGestureRecognizer:panGestureRecognizer];
}
[self.view addSubview:_maxImageView];
return _maxImageView;
}
#pragma mark- maxImageView手势事件处理
//MARK: 点击手势
- (void)maxImageViewTap {
// 让图片回复最初大小，并从父视图移除
self.maxImageView.frame = self.oldFrame;
[self.maxImageView removeFromSuperview];
}
//MARK: 缩放手势
- (void) pinchView:(UIPinchGestureRecognizer *)pinchGestureRecognizer {
UIView *view = pinchGestureRecognizer.view;
if (pinchGestureRecognizer.state == UIGestureRecognizerStateBegan || pinchGestureRecognizer.state == UIGestureRecognizerStateChanged) {
view.transform = CGAffineTransformScale(view.transform, pinchGestureRecognizer.scale, pinchGestureRecognizer.scale);
if (self.maxImageView.frame.size.width < self.oldFrame.size.width) { //让图片无法缩得比原图小
self.maxImageView.frame = self.oldFrame;
}
if (self.maxImageView.frame.size.width > 3 * self.oldFrame.size.width) {// 设置最大放大图
self.maxImageView.frame = self.largeFrame;
}
pinchGestureRecognizer.scale = 1;
}
}
//MARK: 拖拉手势
- (void) panView:(UIPanGestureRecognizer *)panGestureRecognizer {
UIView *view = panGestureRecognizer.view;
if (panGestureRecognizer.state == UIGestureRecognizerStateBegan || panGestureRecognizer.state == UIGestureRecognizerStateChanged) {
CGPoint translation = [panGestureRecognizer translationInView:view.superview];
double X ;
double Y;
// 在此需要判断中心点有没有越界（即图片移动后保证不和屏幕边界产生空白处）
if (view.center.x + translation.x < - (CGRectGetWidth(view.frame)/2 - SCREENSIZE.width)) {
X = - (CGRectGetWidth(self.maxImageView.frame)/2 - SCREENSIZE.width);
}else if(view.center.x + translation.x > CGRectGetWidth(view.frame)/2) {
X = CGRectGetWidth(view.frame)/2;
}else {
X = view.center.x + translation.x;
}
if (view.center.y + translation.y < - (CGRectGetHeight(view.frame)/2 - SCREENSIZE.height)) {
Y = - (CGRectGetHeight(view.frame)/2 - SCREENSIZE.height);
}else if(view.center.y + translation.y - 64 > CGRectGetHeight(view.frame)/2) {
Y = CGRectGetHeight(view.frame)/2 + 64;
}else {
Y = view.center.y + translation.y;
}
[view setCenter:(CGPoint){X, Y}];
}
[panGestureRecognizer setTranslation:CGPointZero inView:view.superview];
}
@end
