而如果要想更精细的处理,我们还需要借助touchesBegan,touchesMoved,touchesEnded等触摸方法。这些方法都是UIResponder中的方法。视图控制器和视图类,都是UIResponder的子类。正是这个类,让UIView等相关触摸事件得以响应。
具体方法介绍如下:
1,func touchesBegan(touches: NSSet,withEvent event: UIEvent)
touches是UITouch的集合,通过UITouch我们可以检测触摸事件的属性,是单拍还是双拍,还有触摸的位置等。
2,func touchesMoved(touches: NSSet,51); font-family:arial; font-size:14px">
告诉接收者一个或者多个手指在视图或者窗口上触发移动事件。
默认不允许多点触摸。如果要接收多点触摸事件必须将UIView的属性设置为true。
3,func touchesEnded(touches: NSSet,51); font-family:arial; font-size:14px">
当一个触摸事件结束时发出的UITouch实例对象。
4,func touchesCancelled(touches: NSSet,51); font-family:arial; font-size:14px">
通知接收者当系统发出取消事件的时候(如低内存消耗的告警框)
下面通过一个样例演示触摸事件得用法:
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import
UIKit
class
ViewController
:
UIViewController
{
override
func
viewDidLoad() {
super
.viewDidLoad()
//支持多点触摸
self
.view.multipleTouchEnabled =
true
}
didReceiveMemoryWarning() {
.didReceiveMemoryWarning()
}
touchesBegan(touches:
Set
<
UITouch
>,withEvent event:
UIEvent
?) {
for
touch:
AnyObject
in
touches {
let
t:
= touch
as
!
UITouch
//当在屏幕上连续拍动两下时,背景恢复为白色
if
(t.tapCount == 2)
{
.view.backgroundColor =
UIColor
.whiteColor()
}
//当在屏幕上单击时,屏幕变为红色
else
(t.tapCount == 1)
{
.redColor()
}
print
(
"event begin!"
)
}
}
touchesMoved(touches:
?) {
touches {
UITouch
(t.locationInView(
.view))
}
}
touchesEnded(touches:
?) {
//两点触摸时,计算两点间的距离,以及角度
touches.count == 2{
//获取触摸点
first = (touches
as
NSSet
).allObjects[0]
UITouch
second = (touches
).allObjects[1]
UITouch
//获取触摸点坐标
@H_428_403@firstPoint = first.locationInView(
.view)
secondPoint = second.locationInView(
.view)
//计算两点间的距离
deltaX = secondPoint.x - firstPoint.x
deltaY = secondPoint.y - firstPoint.y
initialDistance = sqrt(deltaX*deltaX + deltaY*deltaY)
"两点间距离:\(initialDistance)"
)
//计算两点间的角度
height = secondPoint.y - firstPoint.y
width = firstPoint.x - secondPoint.x
rads = atan(height/width);
degrees = 180.0 *
Double
(rads) /
M_PI
"两点间角度:\(degrees)"
)
}
"event end!"
)
}
touchesCancelled(touches:
>?,monospace!important; min-height:inherit!important">?) {
"event canceled!"
)
}
}
|