Android编程使用GestureDetector实现简单手势监听与处理的方法

package com.example.gesturedetector;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
   ImageView img;
  GestureDetector myGestureDetector;
  class myGestureListener extends GestureDetector.SimpleOnGestureListener {
    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
      if (e1.getX()-e2.getX()>50)
      {
        Toast.makeText(MainActivity.this,"从右往左滑动",Toast.LENGTH_LONG).show();
      }else if(e2.getX()-e1.getX()>50){
        Toast.makeText(MainActivity.this,"从左往右滑动",Toast.LENGTH_LONG).show();
      }
      return super.onFling(e1, e2, velocityX, velocityY);
    }
  }
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    img = (ImageView) findViewById(R.id.img);
    myGestureDetector = new GestureDetector(new myGestureListener());
    img.setOnTouchListener(new View.OnTouchListener() {
      //motionEvent可以捕捉我们触摸屏幕的event事件
      @Override
      public boolean onTouch(View view, MotionEvent motionEvent) {
        myGestureDetector.onTouchEvent(motionEvent);
        return true;
      }
    });
  }
}

<&＃63;xml version="1.0" encoding="utf-8"&＃63;>