I use this for scaling and dragging an UIView in my app.
1) 首先确保将以下内容添加到您的实现中,并将输出连接到您在Storyboard中的视图。
#import <QuartzCore/QuartzCore.h>
@interface yourclass () {
BOOL isDragging;
}
@property (weak, nonatomic) IBOutlet UIImageView *outletMainView;
@property (weak, nonatomic) IBOutlet UIImageView *outletRedDot;
当触摸开始时,我会在用户触摸特定视图(这里是红点)时稍微缩放视图。
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint touchLocation = [touch locationInView:self.outletMainView];
CGRect redDotRect = [self.outletRedDot frame];
if (CGRectContainsPoint(redDotRect, touchLocation)) {
isDragging = YES;
NSLog(@"Red Dot tapped!");
[UIView animateWithDuration:0.2
delay:0.0
options:UIViewAnimationOptionCurveEaseOut
animations:^{
self.outletRedDot.transform = CGAffineTransformMakeScale(1.75, 1.75);
}
completion:^(BOOL finished) {
}];
} else {
return;
}
}
2) 然后我将视图设置为跟随手指点的位置
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint touchLocation = [touch locationInView:self.outletMainView];
if (isDragging) {
[UIView animateWithDuration:0.0f
delay:0.0f
options:(UIViewAnimationOptionBeginFromCurrentState|UIViewAnimationOptionCurveEaseInOut)
animations:^{
self.outletRedDot.center = touchLocation;
NSLog(@"X: %0.2f Y: %0.2f",touchLocation.x-redDotStartCenter.x, redDotStartCenter.y-touchLocation.y);
}
completion:NULL];
}
}
3) 最后,当拖动结束时,视图被重置为其原始比例。
- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint touchLocation = [touch locationInView:self.outletMainView];
CGRect redDotRect = [self.outletRedDot frame];
if (CGRectContainsPoint(redDotRect, touchLocation)) {
[UIView animateWithDuration:0.1
delay:0.0
options:0
animations:^{
self.outletRedDot.transform = CGAffineTransformMakeScale(1.0, 1.0);
}
completion:^(BOOL finished) {
}];
}
isDragging = NO;
}