【移动应用开发技术】Android中怎么侦测滑动手势

【移动应用开发技术】Android中怎么侦测滑动手势

Android中怎么侦测滑动手势，相信很多没有经验的人对此束手无策，为此本文总结了问题出现的原因和解决方法，通过这篇文章希望你能解决这个问题。Android

SDK提供了一个listener类来侦测各种不同的手势:SimpleOnGestureListener.

你只需要实现自己所关心的手势就可以了.Swipe在android里面是叫Fling首先创建自己的一个手势detector类:class

MyGestureDetector

extends

SimpleOnGestureListener

{

@Override

public

boolean

onFling(MotionEvent

e1,

MotionEvent

e2,

float

velocityX,

float

velocityY)

{

}

class

MyGestureDetector

extends

SimpleOnGestureListener

{

@Override

public

boolean

onFling(MotionEvent

e1,

MotionEvent

e2,

float

velocityX,

float

velocityY)

{

}

一个Android滑动手势有几个特征,

比如是在x或者y轴上近乎直线的划动,

中途路径的偏差不能太大,

而且划动需要一定的速度,

所以我们定义几个定量:private

static

final

int

SWIPE_MIN_DISTANCE

=

120;

private

static

final

int

SWIPE_MAX_OFF_PATH

=

250;

private

static

final

int

SWIPE_THRESHOLD_VELOCITY

=

200;

private

static

final

int

SWIPE_MIN_DISTANCE

=

120;

private

static

final

int

SWIPE_MAX_OFF_PATH

=

250;

private

static

final

int

SWIPE_THRESHOLD_VELOCITY

=

200;

然后在onFling方法中,

判断是不是一个合理的swipe动作:if(e1.getX()

-

e2.getX()

>

SWIPE_MIN_DISTANCE

&&

Math.abs(velocityX)

>

SWIPE_THRESHOLD_VELOCITY)

{

viewFlipper.setInAnimation(slideLeftIn);

viewFlipper.setOutAnimation(slideLeftOut);

viewFlipper.showNext();

}

else

if

(e2.getX()

-

e1.getX()

>

SWIPE_MIN_DISTANCE

&&

Math.abs(velocityX)

>

SWIPE_THRESHOLD_VELOCITY)

{

viewFlipper.setInAnimation(slideRightIn);

viewFlipper.setOutAnimation(slideRightOut);

viewFlipper.showPrevious();

}

if(e1.getX()

-

e2.getX()

>

SWIPE_MIN_DISTANCE

&&

Math.abs(velocityX)

>

SWIPE_THRESHOLD_VELOCITY)

{

viewFlipper.setInAnimation(slideLeftIn);

viewFlipper.setOutAnimation(slideLeftOut);

viewFlipper.showNext();

}

else

if

(e2.getX()

-

e1.getX()

>

SWIPE_MIN_DISTANCE

&&

Math.abs(velocityX)

>

SWIPE_THRESHOLD_VELOCITY)

{

viewFlipper.setInAnimation(slideRightIn);

viewFlipper.setOutAnimation(slideRightOut);

viewFlipper.showPrevious();

}

if(e1.getX()

-

e2.getX()

>

SWIPE_MIN_DISTANCE

&&

Math.abs(velocityX)

>

SWIPE_THRESHOLD_VELOCITY)

{

viewFlipper.setInAnimation(slideLeftIn);

viewFlipper.setOutAnimation(slideLeftOut);

viewFlipper.showNext();

}

else

if

(e2.getX()

-

e1.getX()

>

SWIPE_MIN_DISTANCE

&&

Math.abs(velocityX)

>

SWIPE_THRESHOLD_VELOCITY)

{

viewFlipper.setInAnimation(slideRightIn);

viewFlipper.setOutAnimation(slideRightOut);

viewFlipper.showPrevious();

}

if(e1.getX()

-

e2.getX()

>

SWIPE_MIN_DISTANCE

&&

Math.abs(velocityX)

>

SWIPE_THRESHOLD_VELOCITY)

{

viewFlipper.setInAnimation(slideLeftIn);

viewFlipper.setOutAnimation(slideLeftOut);

viewFlipper.showNext();

}

else

if

(e2.getX()

-

e1.getX()

>

SWIPE_MIN_DISTANCE

&&

Math.abs(velocityX)

>

SWIPE_THRESHOLD_VELOCITY)

{

viewFlipper.setInAnimation(slideRightIn);

viewFlipper.setOutAnimation(slideRightOut);

viewFlipper.showPrevious();

}

这里的viewFlipper是含有多个view的一个container,

可以很方便的调用prev/next

view,

加上animation动画,

可以达到一些不错的效果:viewFlipper

=

(ViewFlipper)findViewById(R.id.flipper);

slideLeftIn

=

AnimationUtils.loadAnimation(this,

R.anim.slide_left_in);

slideLeftOut

=

AnimationUtils.loadAnimation(this,

R.anim.slide_left_out);

slideRightIn

=

AnimationUtils.loadAnimation(this,

R.anim.slide_right_in);

slideRightOut

=

AnimationUtils.loadAnimation(this,

R.anim.slide_right_out);

viewFlipper

=

(ViewFlipper)findViewById(R.id.flipper);

slideLeftIn

=

AnimationUtils.loadAnimation(this,

R.anim.slide_left_in);

slideLeftOut

=

AnimationUtils.loadAnimation(this,

R.anim.slide_left_out);

slideRightIn

=

AnimationUtils.loadAnimation(this,

R.anim.slide_right_in);

slideRightOut

=

AnimationUtils.loadAnimation(this,

R.anim.slide_right_out);

自定义的animation可以查看具体的XML,

比如从左边进来的一个动画:<

set

xmlns:android="/apk/res/android">

<

translate

android:fromXDelta="100%p"

android:toXDelta="0"

android:duration="800"/>

<

/set>

<

set

xmlns:android="/apk/res/android">

<

translate

android:fromXDelta="100%p"

android:toXDelta="0"

android:duration="800"/>