<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:app="http://schemas.android.com/apk/res-auto"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"  tools:context="com.example.administrator.hand_gliding.MainActivity">   <ImageView    android:layout_width="match_parent"    android:layout_height="match_parent"    android:id="@+id/imageView"    android:src="@drawable/a1"/> </LinearLayout>

package com.example.administrator.hand_gliding; import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.GestureDetector;import android.view.MotionEvent;import android.widget.ImageView; public class MainActivity extends AppCompatActivity {   //定義圖片  private int[] resId = new int[]{      R.drawable.a1,R.drawable.a2,R.drawable.a3,R.drawable.a4,      R.drawable.a5,R.drawable.a6,R.drawable.a7  };  //圖片下標(biāo)序號(hào)  private int count = 0;  //定義手勢監(jiān)聽對(duì)象  private GestureDetector gestureDetector;  //定義ImageView對(duì)象  private ImageView iv;   @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);        iv = (ImageView)findViewById(R.id.imageView);        //獲取ImageView控件id    gestureDetector = new GestureDetector(onGestureListener);  //設(shè)置手勢監(jiān)聽由onGestureListener處理   }   //當(dāng)Activity被觸摸時(shí)回調(diào)  public boolean onTouchEvent(MotionEvent event){    return gestureDetector.onTouchEvent(event);  }  //自定義GestureDetector的手勢識(shí)別監(jiān)聽器  private GestureDetector.OnGestureListener onGestureListener      = new GestureDetector.SimpleOnGestureListener(){    //當(dāng)識(shí)別的手勢是滑動(dòng)手勢時(shí)回調(diào)onFinger方法    public boolean onFling(MotionEvent e1,MotionEvent e2,float velocityX,float velocityY){      //得到手觸碰位置的起始點(diǎn)和結(jié)束點(diǎn)坐標(biāo) x , y ，并進(jìn)行計(jì)算      float x = e2.getX()-e1.getX();      float y = e2.getY()-e1.getY();      //通過計(jì)算判斷是向左還是向右滑動(dòng)      if(x > 0){        count++;        count%=(resId.length-1);    //想顯示多少圖片，就把定義圖片的數(shù)組長度-1      }else if(x < 0){        count--;        count=(count+(resId.length-1))%(resId.length-1);      }       iv.setImageResource(resId[count]); //切換imageView的圖片      return true;    }  };}