触摸和手势
ResturesAndEventHandle
【手势与事件处理】
所谓手势就是手指在屏幕上的动作
【触摸事件】
重写方法
1、开始
- (void)touchesBegan:(NSSet )touches withEvent:(UIEvent )event;
//每当手指触摸屏幕的时候就会产生一个事件
获取集合中的一个触摸
UITouch *touch = [touches anyObject];
触摸的视图 touch.view
时间戳 (何时触摸)touch.timestamp
点击次数touch.tapCount
触摸的位置 当前的位置
CGPoint currentPoint = [touch locationInView:self.view];
触摸之前的位置
CGPoint pre = [touch previousLocationInView:self.view];
NSLog(@"%@ %@",NSStringFromCGPoint(currentPoint) ,NSStringFromCGPoint(pre) );
- 2、移动
- (void)touchesMoved:(NSSet )touches withEvent:(UIEvent )event;
//事件传递是从上往下，UILabel和UIImageView 默认是不接收事件的，如果要开启，设置userInteractionEnabled = YES
//触摸是从下往上 ，会先检测父视图能不能接受触摸，如果能 父视图的里边的空间都可以接受触摸，如果不能，父视图的控件，不管怎么设置都不能接收事件
判断手势是否在同一视图上
if (touch.view == self.myLabel) {
//获得偏移
CGPoint sub = CGPointMake(currentPoint.x - pre.x, currentPoint.y - pre.y);
//当前位置
CGPoint center = touch.view.center;
//把偏移加上去
center = CGPointMake(center.x + sub.x, center.y + sub.y);
touch.view.center = center;
}
- 3、结束 (void)touchesEnded:(NSSet )touches withEvent:(UIEvent )event;
- 4、取消 (void)touchesCancelled:(NSSet )touches withEvent:(UIEvent )event;
UITouch的常见属性：
tapCount
touch.view 点击的视图
previousLocationInView
locationInView
应用
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint prePoint = [touch previousLocationInView:self.view];
NSLog(@"上一次点击时的坐标：%@",NSStringFromCGPoint(prePoint));
CGPoint currentPoint = [touch locationInView:self.view];
NSLog(@"当前点击的坐标：%@",NSStringFromCGPoint(currentPoint));
CGPoint pointDelt = CGPointMake(currentPoint.x-prePoint.x, currentPoint.y-prePoint.y);
CGPoint center = CGPointMake(_myView.center.x+pointDelt.x, _myView.center.y+pointDelt.y);
[_myView setCenter:center];
}
【各种手势】
1.手势
基类UIGestureRecognizer
UITapGestureRecognizer Tap 点击
UIPanGestureRecognizer Pan (慢速滑动，拖移)
UILongPressGestureRecognizer LongPress (长按)
UIPinGestureRecognizer Pinch （捏合，两手指往内或外拨动）
UIRotationGestureRecognizer Rotation (旋转)
UISwipeGestureRecognizer Swipe (快速滑动，轻扫)
2. UITapGestureRecognizer
点击：
//创建了一个点击的手势
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tap:)];
//设置手势
//点击多少下，事件被调用
tap.numberOfTapsRequired = 2;
//需要多少个手指头
tap.numberOfTouchesRequired = 2;
3. UIPanGestureRecognizer
拖移
- (void)panGestureHandle:(UIPanGestureRecognizer *)pgr
{
switch (pgr.state) {
case UIGestureRecognizerStateBegan:
case UIGestureRecognizerStateChanged:
//NSLog(@"滑动手势识别成功");
{
//获取手势作用的view
UIView *view = pgr.view;
//获取偏移
CGPoint offset = [pgr translationInView:self.view];
//设置偏移
view.transform = CGAffineTransformTranslate(view.transform, offset.x, offset.y);
//因为滑动手势效果会累加，所以每次需要清零
[pgr setTranslation:CGPointZero inView:self.view];
}
break;
case UIGestureRecognizerStateEnded:
NSLog(@"滑动手势识别结束");
break;
default:
break;
}
}
4. UILongPressGestureRecognizer
长按
minimumPressDuration //设置最小持续时间
- (void)longPress:(UILongPressGestureRecognizer *)longPress {
NSLog(@"长按手势：");
switch (longPress.state) {
case UIGestureRecognizerStateBegan:
NSLog(@"开始");
break;
case UIGestureRecognizerStateEnded:
NSLog(@"结束");
break;
default:
break;
}
}
5. UIPinGestureRecognizer
捏合
- (void)pinchGestureHandle:(UIPinchGestureRecognizer *)pgr
{
switch (pgr.state) {
case UIGestureRecognizerStateBegan:
case UIGestureRecognizerStateChanged:
{
UIView *view = pgr.view;
view.transform = CGAffineTransformScale(view.transform, pgr.scale, pgr.scale);
//缩放比例会累加，所以需要重新复位
pgr.scale = 1;
}
break;
case UIGestureRecognizerStateEnded:
NSLog(@"捏合手势结束");
break;
default:
break;
}
}
加一个复位按钮
_imageView.transform = CGAffineTransformIdentity;
6. UIRotationGestureRecognizer
旋转
- (void)rotation:(UIRotationGestureRecognizer *)sender {
switch (sender.state) {
case UIGestureRecognizerStateBegan:
case UIGestureRecognizerStateChanged:
{
UIView *view = sender.view;
view.transform = CGAffineTransformRotate(view.transform, sender.rotation);
sender.rotation = 0;
}
break;
default:
break;
}
}
7轻扫
//添加滑动事件，有方向限制
- (void)addSwipe {
UISwipeGestureRecognizerDirection directions[] = {
UISwipeGestureRecognizerDirectionDown,
UISwipeGestureRecognizerDirectionLeft,
UISwipeGestureRecognizerDirectionRight,
UISwipeGestureRecognizerDirectionUp
};
for (int i = 0; i < 4 ; i++) {
UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipe:)];
swipe.direction = directions[i];
[self.myLabel addGestureRecognizer:swipe];
}
}
#define step 10;
- (void)swipe:(UISwipeGestureRecognizer*)sender {
UIView *view = sender.view;
CGPoint offset = CGPointZero;
switch (sender.direction) {
case UISwipeGestureRecognizerDirectionUp:
offset.y -= step;
break;
case UISwipeGestureRecognizerDirectionDown:
offset.y += step;
break;
case UISwipeGestureRecognizerDirectionLeft:
offset.x -= step;
break;
case UISwipeGestureRecognizerDirectionRight:
offset.x += 10;
break;
default:
break;
}
view.transform = CGAffineTransformTranslate(view.transform, offset.x, offset.y);
}
是否允许识别多个手势
遵守协议<UIGestureRecognizerDelegate>
/**
* 实现协议的方法// 一个手势检测到了，并不影响另一个手势的检测
*/
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
if (gestureRecognizer.view == otherGestureRecognizer.view) {
return YES;
}
return NO;
}
晃动事件
参考day08
晃动事件接口
- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
{
[super motionBegan:motion withEvent:event];
//NSLog(@”晃动开始”);
} - (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event
{
NSLog(@”晃动结束”);
} - (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event
{
NSLog(@”滑动被取消”);
}
// 把image中的rect区域拿出来作为一个新的图片
- (UIImage )clipImage:(UIImage )image withRect:(CGRect)rect {
- CGImageRef imageRef = CGImageCreateWithImageInRect(image.CGImage, rect);
- return [UIImage imageWithCGImage:imageRef];
- }
