iPhone开发中touch的事件随笔
在ViewController中重写touch的事件的方法体就可实现特定的touch功能(但这些touch事件会被加在之上的tableView或scrollView等屏蔽,希望知道解决方案的留下方法).
下面代码实现清扫事件
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
messageLabel.text =@"Touches Began"; //开始触摸的方法
[self updateLabelsFromTouches:touches];
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event{
messageLabel.text =@"Touches Cancelled";//触摸取消的方法
[self updateLabelsFromTouches:touches];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
messageLabel.text =@"Touches Stopped.";//触摸结束的方法
[self updateLabelsFromTouches:touches];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
messageLabel.text =@"Drag Detected";//触摸移动的方法
[self updateLabelsFromTouches:touches];
}
触摸-轻扫:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
gestureStartPoint = [touch locationInView:self.view];//开始触摸
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint currentPosition = [touch locationInView:self.view];
CGFloat deltaX = fabsf(gestureStartPoint.x - currentPosition.x);
CGFloat deltaY = fabsf(gestureStartPoint.y - currentPosition.y);
if (deltaX >= kMinimumGestureLength && deltaY <=kMaximumVariance)
{//kMinimumGestureLength 最小移动长度 kMaximumVariance 最大偏移长度
label.text =@"Horizontal swipe detected";//水平消除
[self performSelector:@selector(eraseText)
withObject:nil afterDelay:2];
}
elseif (deltaY >= kMinimumGestureLength &&
deltaX <= kMaximumVariance)
{
label.text =@"Vertical swipe detected";//垂直消除
[self performSelector:@selector(eraseText) withObject:nil
afterDelay:2];
}
}
多次轻击判断:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];//实例一个uitouch
NSUInteger tapCount = [touch tapCount]; //计算touch的tapCount次数
switch (tapCount)
{
case1:
[self singleTap];
break;
case2:
[self doubleTap];
break;
case3:
[self tripleTap];
break;
case4:
[self quadrupleTap];
break;
default:
break;
}
}
捏合操作:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{//开始触碰
if ([touches count] ==2)
{//检测是否为两个手指触点
NSArray *twoTouches = [touches allObjects];
UITouch *first = [twoTouches objectAtIndex:0];
UITouch *second = [twoTouches objectAtIndex:1];
initialDistance = distanceBetweenPoints([first locationInView:self.view],
[second locationInView:self.view]);
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{//移动手指
if ([touches count] ==2)
{
NSArray *twoTouches = [touches allObjects];
UITouch *first = [twoTouches objectAtIndex:0];
UITouch *second = [twoTouches objectAtIndex:1];
CGFloat currentDistance = distanceBetweenPoints([first locationInView:self.view],
[second locationInView:self.view]);
if (initialDistance ==0)
initialDistance = currentDistance; //根据移动前后的坐标距离差检测是捏合的手势还是打开的手势
elseif (currentDistance - initialDistance > kMinimumPinchDelta)
{//检测是否大于最小移动值kMinimumPinchDelta
label.text =@"Outward Pinch";
[self performSelector:@selector(eraseLabel)
withObject:nil
afterDelay:1.6f];
}
elseif (initialDistance - currentDistance > kMinimumPinchDelta)
{
label.text =@"Inward Pinch";
[self performSelector:@selector(something)
withObject:nil
afterDelay:1.6f];
}
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{//触碰结束
initialDistance =0;
}
自定义手势“√”:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint point = [touch locationInView:self.view];
lastPreviousPoint = point;
lastCurrentPoint = point;
lineLengthSoFar =0.0f;
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint previousPoint = [touch previousLocationInView:self.view];
CGPoint currentPoint = [touch locationInView:self.view];
CGFloat angle = angleBetweenLines(lastPreviousPoint, //计算两条线之间的角度
lastCurrentPoint,
previousPoint,
currentPoint);
if (angle >= kMinimumCheckMarkAngle&& angle <= kMaximumCheckMarkAngle
&& lineLengthSoFar > kMinimumCheckMarkLength)
{//检测手势被承认的条件 kMinimumCheckMarkAngle 最小角度kMaximumCheckMarkAngle最大角度kMinimumCheckMarkLength 画线最小长度
label.text =@"Checkmark";
[self performSelector:@selector(something)
withObject:nil afterDelay:1.6];
}
lineLengthSoFar += distanceBetweenPoints(previousPoint, currentPoint);//lineLengthSoFar , lastPreviousPoint, lastCurrentPoint 重新赋值
lastPreviousPoint = previousPoint;
lastCurrentPoint = currentPoint;
}
这里用到一个判断两条直线的角度的方法 angleBetweenLines(CGPoint line1Start, CGPoint line1End, CGPoint line2Start, CGPointlin2End);
by MAC-z