Android高级UI GestureDetector监听各种手势

内容

第一部分：介绍GestureDetector
第二部分：改造之前用ViewFlipper实现的实例，使用GestureDetector实现图片切换功能。

要点

1. 实现接口OnTouchListener,在onTouch()方法中由GestureDetector接管事件
2. 接口OnGestureListener
3. 接口OnDoubleTapListener
4. 静态类SimpleOnGestureListener
   实现了2、3两个接口，却没有做具体事情。可以继承该类，需要哪个就override哪个部分。

xml

一般的布局即可

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/gesture_detector_linearlayout"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.example.feather.androiddemos.GestureDetectorActivity"></LinearLayout>

Java中使用GestureDetector

推荐使用SimpleOnGestureListener

//实现OnTouchListenerpublic class GestureDetectorActivity extends AppCompatActivity implements View.OnTouchListener{    private LinearLayout linearLayout;    private GestureDetector gestureDetector;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_gesture_detector);        linearLayout = (LinearLayout) findViewById(R.id.gesture_detector_linearlayout);//获取该布局        linearLayout.setOnTouchListener(this);//设置监听器        //获取GestureDetector        gestureDetector = new GestureDetector(this,                new SimpleOnGestureListener() //下面实现的class(类)        );    }    @Override    public boolean onTouch(View v, MotionEvent event) {        gestureDetector.onTouchEvent(event); //由GestureDetector进行接管，消耗掉event        return false;    }    //继承静态类，重写相应方法    class SimpleOnGestureListener extends GestureDetector.SimpleOnGestureListener{         @Override//该方法就是按下时触发，此外还有近十种方法        public boolean onDown(MotionEvent e) {            Toast.makeText(GestureDetectorActivity.this, "onDown", Toast.LENGTH_SHORT).show();            return super.onDown(e);        }    }}

ViewFliper和GestureDetector实现图片切换

之前ViewFliper教程链接如下：http://blog.csdn.net/feather_wch/article/details/51535660

我们将在本教程基础上进行修改：
将ViewFlipperActivity中置换为如下内容即可

public class ViewFlipperActivity extends AppCompatActivity implements View.OnTouchListener{    ViewFlipper viewFlipper = null; //ViewFlipper控件    GestureDetector gestureDetector = null;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_view_flipper);        viewFlipper = (ViewFlipper) findViewById(R.id.ViewFlipper);//获取自动切换        viewFlipper.setOnTouchListener(this);        gestureDetector = new GestureDetector(this, new SimpleOnGestureListener()); //初始化GestureDetector    }    @Override    public boolean onTouch(View v, MotionEvent event) { //触屏        //使用GestureDetector        gestureDetector.onTouchEvent(event); //GestureDetector接管触屏按键        return false;    }    //继承静态类，重写相应方法    class SimpleOnGestureListener extends GestureDetector.SimpleOnGestureListener{        @Override        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {            if(e2.getX() - e1.getX() > 100)//从左向右            {                //设置切换动画                viewFlipper.setInAnimation(AnimationUtils.loadAnimation(ViewFlipperActivity.this, R.anim.push_right_in));                viewFlipper.setOutAnimation(AnimationUtils.loadAnimation(ViewFlipperActivity.this, R.anim.push_right_out));                //显示上一个View                viewFlipper.showPrevious(); //从左向右,显示上一幅图片            }else if(e1.getX() - e2.getX() > 100)            {                //设置切换动画                viewFlipper.setInAnimation(AnimationUtils.loadAnimation(ViewFlipperActivity.this, R.anim.push_left_in));                viewFlipper.setOutAnimation(AnimationUtils.loadAnimation(ViewFlipperActivity.this, R.anim.push_left_out));                viewFlipper.showNext(); //从左向右,显示下一幅图片            }            return true;        }        public SimpleOnGestureListener() {            super();        }    }}