UITouch的用法
UITouch一般无法直接获取，是通过UIView的touchesBegan等函数获得。
//这四个方法是UIResponder中得方法
// Generally, all responders which do custom touch handling should override all four of these methods.
// Your responder will receive either touchesEnded:withEvent: or touchesCancelled:withEvent: for each
// touch it is handling (those touches it received in touchesBegan:withEvent:).
// *** You must handle cancelled touches to ensure correct behavior in your application. Failure to
// do so is very likely to lead to incorrect behavior or crashes.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event;
前面写了几次提到UITouch，也提到了UITouch的三个代理方法
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
这里还有几个代理方法
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event;//触摸取消事件
- (void)remoteControlReceivedWithEvent:(UIEvent *)event;//注册接受触摸事件的Control
下面写了一个简单的DEMO，触摸时，移动图片
- (void)loadView {
[super loadView];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
UIImageView *image = [[UIImageView alloc] initWithFrame:CGRectMake(20.0, 50.0, 45.0, 45.0)];
image.image = [UIImage imageNamed:@"1.png"];
image.tag = 100;
[self.view addSubview:image];
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
UIImageView *view1 = (UIImageView*)[self.view viewWithTag:100];
CGPoint point = [touch locationInView:self.view];
CGRect frame = view1.frame;
frame.origin = point;
view1.frame = frame;
}
效果
