Android技术——视图切换（一）~（四）项目的源代码在：https://github.com/YongYuIT/MeiNv_Liulanqi
上文《Android技术——视图切换（三）》实现的图片切换，虽然切换时有动画效果，但是却需要使用按钮才能切换。这个实例中，将尝试用手势识别代替按钮来实现图片切换。
这个实例也是基于前三篇文章里的项目添加而来的。
/MeiNv_Liulanqi/res/layout/activity_view_switcher_huadong.xml文件：
<RelativeLayout xmlns:android="" android:layout_width="fill_parent" android:layout_height="fill_parent" > <!– 定义一个ViewSwitcher组件 –> <ViewSwitcher android:id="@+id/viewSwitcher" android:layout_width="fill_parent" android:layout_height="fill_parent" /> <!– 定义滚动到上一屏的按钮 –></RelativeLayout>
/MeiNv_Liulanqi/src/com/example/meinv_liulanqi/ViewSwitcherHuadongActivity.java文件：
package com.example.meinv_liulanqi;import android.app.Activity;import android.os.Bundle;import android.view.GestureDetector;import android.view.LayoutInflater;import android.view.MotionEvent;import android.view.View;import android.view.View.OnTouchListener;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.ViewSwitcher;import android.widget.ViewSwitcher.ViewFactory;public class ViewSwitcherHuadongActivity extends Activity{ private int screenNo = -1; private int screenNum; public ViewSwitcher switcher; public int[] img_ids; private GestureDetector myDesDet; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_view_switcher_huadong); // GestureDetector用于从OnTouchListener的onTouch函数中接收数据由此判别手势， // 识别出手势后，由OnGestureListener响应。 myOnGestureListener listener = new myOnGestureListener(this); myDesDet = new GestureDetector(listener); img_ids = new int[] { R.drawable.linzhiling, R.drawable.liuyan, R.drawable.yangmi }; screenNum = img_ids.length; // 为ViewSwitcher提供视图工厂 switcher = (ViewSwitcher) findViewById(R.id.viewSwitcher); myViewFactory factory = new myViewFactory(this.getLayoutInflater(), myDesDet); switcher.setFactory(factory); // 初始化 getNext(switcher, img_ids); } public void getNext(ViewSwitcher _switcher, int[] _img_ids) { if (screenNo < screenNum – 1) { screenNo++; // 设置视图切换的动画效果 _switcher.setInAnimation(ViewSwitcherHuadongActivity.this, R.anim.slide_in_right); _switcher.setOutAnimation(ViewSwitcherHuadongActivity.this, R.anim.slide_out_left); // 获取下一个视图的实例 LinearLayout lil = (LinearLayout) _switcher.getNextView(); ImageView img = (ImageView) lil.findViewById(R.id.img_meinv); img.setImageResource(_img_ids[screenNo]); // 切换视图 _switcher.showNext(); } } public void getPrev(ViewSwitcher _switcher, int[] _img_ids) { if (screenNo > 0) { screenNo–; // 设置视图切换的动画效果 _switcher.setInAnimation(ViewSwitcherHuadongActivity.this, R.anim.slide_in_lef); _switcher.setOutAnimation(ViewSwitcherHuadongActivity.this, R.anim.slide_out_right); // 获取下一个视图的实例 LinearLayout lil = (LinearLayout) _switcher.getNextView(); ImageView img = (ImageView) lil.findViewById(R.id.img_meinv); img.setImageResource(_img_ids[screenNo]); // 切换视图 _switcher.showPrevious(); } } class myViewFactory implements ViewFactory { private LayoutInflater inflater; private GestureDetector desDet; public myViewFactory(LayoutInflater _inf, GestureDetector _desDet) { inflater = _inf; desDet = _desDet; } @Override public View makeView() { // 提供下一个视图的实例 View v = inflater.inflate(R.layout.fragment_layout, null); ImageView img = (ImageView) v.findViewById(R.id.img_meinv); // 为图片注册触摸事件监听器 img.setOnTouchListener(new myOnTouchListener(desDet)); return v; } } // 扩展得到自己的触摸事件监听器 class myOnTouchListener implements OnTouchListener { private GestureDetector desDet; public myOnTouchListener(GestureDetector _desDet) { desDet = _desDet; } @Override public boolean onTouch(View arg0, MotionEvent arg1) { // 将监听数据传到GestureDetector，GestureDetector可以从中判别手势 return desDet.onTouchEvent(arg1); } }}
/MeiNv_Liulanqi/src/com/example/meinv_liulanqi/myOnGestureListener.java文件：
当你开展的事业从事的行动穷途末路大势已去的时候，
