項目中要求對UIImageView進行放大和拖動，所以記錄一下。
@interface PutQuestionToViewController ()\
@property (nonatomic, strong) UIImageView *maxImageView;
/** 記錄大圖的原始尺寸 */
@property (nonatomic, assign) CGRect oldFrame;
/** 大圖的最大放大尺寸 */
@property (nonatomic, assign) CGRect largeFrame;
@end
@implementation PutQuestionToViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
// 添加圖片
self.maxImageView.image = [UIImage imageNamed:@"picture"];
}
//MARK: 大圖maxImageView
- (UIImageView *)maxImageView {
if (!_maxImageView) {
_maxImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 64, SCREENSIZE.width, SCREENSIZE.height - 64)];
_oldFrame = _maxImageView.frame;// 記錄原始尺寸
_largeFrame = CGRectMake(0 - SCREENSIZE.width, 0 - SCREENSIZE.height, 3 * _oldFrame.size.width, 3 * _oldFrame.size.height);// 制定最大放大尺寸////
// 允許imageView響應用戶操作(切記要讓ImageView響應用戶操作)
_maxImageView.userInteractionEnabled = YES;
// 添加點擊手勢
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(maxImageViewTap)];
tap.numberOfTapsRequired = 1;// 點擊次數
tap.numberOfTouchesRequired = 1;// 幾個手指
[_maxImageView addGestureRecognizer:tap];
// 添加縮放手勢
UIPinchGestureRecognizer *pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchView:)];
[_maxImageView addGestureRecognizer:pinchGestureRecognizer];
// 添加移動手勢
UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panView:)];
[_maxImageView addGestureRecognizer:panGestureRecognizer];
}
[self.view addSubview:_maxImageView];
return _maxImageView;
}
#pragma mark- maxImageView手勢事件處理
//MARK: 點擊手勢
- (void)maxImageViewTap {
// 讓圖片回復最初大小，并從父視圖移除
self.maxImageView.frame = self.oldFrame;
[self.maxImageView removeFromSuperview];
}
//MARK: 縮放手勢
- (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) { //讓圖片無法縮得比原圖小
self.maxImageView.frame = self.oldFrame;
}
if (self.maxImageView.frame.size.width > 3 * self.oldFrame.size.width) {// 設置最大放大圖
self.maxImageView.frame = self.largeFrame;
}
pinchGestureRecognizer.scale = 1;
}
}
//MARK: 拖拉手勢
- (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;
// 在此需要判斷中心點有沒有越界（即圖片移動后保證不和屏幕邊界產生空白處）
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
