Android手势识别

package com.example.gesturelistener0810;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnTouchListener {
    private TextView textView;
    private GestureDetector gestureDetector;
    public static final String TAG ="hello";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //步骤1:创建手势检测器实例
        gestureDetector = new GestureDetector(this,new GestureDetectorListener());
        textView = findViewById(R.id.text_view);
        //让某个View检测手势，重写View的onTouch函数，将触屏事件交给GestureDetector进行处理
        textView.setOnTouchListener(this);
    }

    @Override
    public boolean onTouch(View view, MotionEvent motionEvent) {
        return gestureDetector.onTouchEvent(motionEvent);
    }

    private class GestureDetectorListener implements GestureDetector.OnGestureListener {
        @Override
        public boolean onDown(MotionEvent motionEvent) {
            Log.d(TAG, "onDown: ");
            return false;
        }

        @Override
        public void onShowPress(MotionEvent motionEvent) {
            Log.d(TAG, "onShowPress: ");
        }

        @Override
        public boolean onSingleTapUp(MotionEvent motionEvent) {
            Log.d(TAG, "onSingleTapUp: ");
            return false;
        }

        @Override
        public boolean onScroll(MotionEvent motionEvent, MotionEvent motionEvent1, float v, float v1) {
            Log.d(TAG, "onScroll: ");
            return false;
        }

        @Override
        public void onLongPress(MotionEvent motionEvent) {
            Log.d(TAG, "onLongPress: ");
        }

        @Override
        public boolean onFling(MotionEvent motionEvent, MotionEvent motionEvent1, float v, float v1) {
            Log.d(TAG, "onFling: ");
            return false;
        }
    }
}

---

他人编写

TextView mTextView;
GestureDetector mGestureDetector;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // 步骤1：创建手势检测器实例 & 传入OnGestureListener接口（需要复写对应方法）
    mGestureDetector = new GestureDetector(this, new GestureDetector.OnGestureListener() {

        // 1. 用户轻触触摸屏
        public boolean onDown(MotionEvent e) {
            Log.i("MyGesture1", "onDown");
            return false;
        }

        // 2. 用户轻触触摸屏，尚未松开或拖动
        // 与onDown()的区别：无松开 / 拖动
        // 即：当用户点击的时，onDown（）就会执行，在按下的瞬间没有松开 / 拖动时onShowPress就会执行
        public void onShowPress(MotionEvent e) {
            Log.i("MyGesture", "onShowPress");
        }

        // 3. 用户长按触摸屏
        public void onLongPress(MotionEvent e) {
            Log.i("MyGesture", "onLongPress");
        }

        // 4. 用户轻击屏幕后抬起
        public boolean onSingleTapUp(MotionEvent e) {
            Log.i("MyGesture", "onSingleTapUp");
            return true;
        }

        // 5. 用户按下触摸屏 & 拖动
        public boolean onScroll(MotionEvent e1, MotionEvent e2,
                                float distanceX, float distanceY) {
            Log.i("MyGesture", "onScroll:");
            return true;
        }

        // 6. 用户按下触摸屏、快速移动后松开
        // 参数：
        // e1：第1个ACTION_DOWN MotionEvent
        // e2：最后一个ACTION_MOVE MotionEvent
        // velocityX：X轴上的移动速度，像素/秒
        // velocityY：Y轴上的移动速度，像素/秒
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
                               float velocityY) {
            Log.i("MyGesture", "onFling");
            return true;
        }

    });

    // 步骤2：创建 & 设置OnDoubleTapListener接口实现类
    mGestureDetector.setOnDoubleTapListener(new GestureDetector.OnDoubleTapListener() {

        // 1. 单击事件
        // 关于OnDoubleTapListener.onSingleTapConfirmed（）和 OnGestureListener.onSingleTapUp()的区别
        // onSingleTapConfirmed：再次点击（即双击），则不会执行
        // onSingleTapUp：手抬起就会执行
        public boolean onSingleTapConfirmed(MotionEvent e) {
            Log.i("MyGesture", "onSingleTapConfirmed");
            return false;
        }

        // 2. 双击事件
        public boolean onDoubleTap(MotionEvent e) {
            Log.i("MyGesture", "onDoubleTap");
            return false;
        }
        // 3. 双击间隔中发生的动作
        // 指触发onDoubleTap后，在双击之间发生的其它动作，包含down、up和move事件；
        public boolean onDoubleTapEvent(MotionEvent e) {
            Log.i("MyGesture", "onDoubleTapEvent");
            return false;
        }
    });

    // 步骤3：重写View的onTouch函数，将触屏事件交给GestureDetector处理，从而对用户手势作出响应
    mTextView = (TextView) findViewById(R.id.textView);

    mTextView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            mGestureDetector.onTouchEvent(event);
            return true;
        }
    });
}

}