Android-手势-实现图片左右滑动效果

实现代码：

package com.chenjun.jun_0710_gesture;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.widget.ImageView;
import android.widget.ViewFlipper;

public class MainActivity extends AppCompatActivity {

    private ViewFlipper vf_main_image;
    private int images[]={R.drawable.s1,R.drawable.s2,R.drawable.s3};
    private GestureDetector gd;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        vf_main_image = (ViewFlipper) findViewById(R.id.vf_main_image);
        for (int i = 0; i < images.length; i++) {
            ImageView iv=new ImageView(this);
            iv.setImageResource(images[i]);
            vf_main_image.addView(iv);
        }
        gd = new GestureDetector(this, new GestureDetector.OnGestureListener() {
            @Override
            public boolean onDown(MotionEvent e) {
                return false;
            }

            @Override
            public void onShowPress(MotionEvent e) {

            }

            @Override
            public boolean onSingleTapUp(MotionEvent e) {
                return false;
            }

            @Override
            public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
                return false;
            }

            @Override
            public void onLongPress(MotionEvent e) {

            }

            @Override
            public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
                if (e2.getX()-e1.getX()>200){
                    vf_main_image.showPrevious();
                }
                if (e1.getX()-e2.getX()>200){
                    vf_main_image.showNext();
                }
                return false;
            }
        });
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        return gd.onTouchEvent(event);
    }
}