Android重写HorizontalScrollView仿ViewPager效果

Android提供的ViewPager类太复杂，有时候没有必要使用，所以重写一个HorizontalScrollView来实现类似的效果，也可以当做Gallery来用

思路很简单，就是重写onTouchEvent事件，在手指抬起或者取消的时候，进行smoothScroll的操作，具体请看代码：

布局文件：activity_test.xml

 <?xml version="1.0" encoding="utf-8"?>
 <com.example.testxinye.MyScrollView
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     >
     <LinearLayout
         android:id="@+id/container"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="horizontal" >

     </LinearLayout>
 </com.example.testxinye.MyScrollView>

Activity类：TestActivity.java

 package com.example.testxinye;

 import android.app.Activity;
 import android.graphics.Color;
 import android.os.Bundle;
 import android.util.DisplayMetrics;
 import android.widget.ImageView;
 import android.widget.ImageView.ScaleType;
 import android.widget.LinearLayout;
 import android.widget.LinearLayout.LayoutParams;
 /**
  *
  * @author xinye
  *
  */
 public class TestActivity extends Activity {
     private LinearLayout mContainer = null;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         // TODO Auto-generated method stub
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_test);

         mContainer = (LinearLayout) findViewById(R.id.container);

         LayoutParams params = new LayoutParams(getWinWidth(), getWinHeight());

         ImageView imageView1 = new ImageView(this);
         imageView1.setLayoutParams(params);
         imageView1.setImageResource(R.drawable.call_show_medal5);
         imageView1.setScaleType(ScaleType.CENTER);
         mContainer.addView(imageView1);

         ImageView imageView2 = new ImageView(this);
         imageView2.setLayoutParams(params);
         imageView2.setImageResource(R.drawable.call_show_medal1);
         imageView2.setScaleType(ScaleType.CENTER);
         imageView2.setBackgroundColor(Color.RED);
         mContainer.addView(imageView2);

         ImageView imageView3 = new ImageView(this);
         imageView3.setLayoutParams(params);
         imageView3.setImageResource(R.drawable.call_show_medal2);
         imageView3.setScaleType(ScaleType.CENTER);
         imageView3.setBackgroundColor(Color.GRAY);
         mContainer.addView(imageView3);

         ImageView imageView4 = new ImageView(this);
         imageView4.setLayoutParams(params);
         imageView4.setImageResource(R.drawable.call_show_medal3);
         imageView4.setScaleType(ScaleType.CENTER);
         imageView4.setBackgroundColor(Color.BLUE);
         mContainer.addView(imageView4);

         ImageView imageView5 = new ImageView(this);
         imageView5.setLayoutParams(params);
         imageView5.setImageResource(R.drawable.call_show_medal4);
         imageView5.setScaleType(ScaleType.CENTER);
         imageView5.setBackgroundColor(Color.GREEN);
         mContainer.addView(imageView5);

     }

     @Override
     protected void onResume() {
 //        ((MyScrollView)mContainer.getParent()).init();
         super.onResume();
     }

     private int getWinWidth(){
         DisplayMetrics dm = new DisplayMetrics();
         //获取屏幕信息
         getWindowManager().getDefaultDisplay().getMetrics(dm);
         return dm.widthPixels;
     }
     private int getWinHeight(){
         DisplayMetrics dm = new DisplayMetrics();
         //获取屏幕信息
         getWindowManager().getDefaultDisplay().getMetrics(dm);
         return dm.heightPixels;
     }
 }

重写的HorizontalScrollView：MyScrollView.java

 package com.example.testxinye;

 import java.util.ArrayList;

 import android.content.Context;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.HorizontalScrollView;
 /**
  *
  * @author XINYE
  *
  */
 public class MyScrollView extends HorizontalScrollView {
     private int subChildCount = 0;
     private ViewGroup firstChild = null;
     private int downX = 0;
     private int currentPage = 0;
     private ArrayList<Integer> pointList = new ArrayList<Integer>();

     public MyScrollView(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
         init();
     }

     public MyScrollView(Context context, AttributeSet attrs) {
         super(context, attrs);
         init();
     }

     public MyScrollView(Context context) {
         super(context);
         init();
     }
     private void init() {
         setHorizontalScrollBarEnabled(false);
     }
     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
         receiveChildInfo();
     }
     public void receiveChildInfo() {

         firstChild = (ViewGroup) getChildAt(0);
         if(firstChild != null){
             subChildCount = firstChild.getChildCount();
             for(int i = 0;i < subChildCount;i++){
                 if(((View)firstChild.getChildAt(i)).getWidth() > 0){
                     pointList.add(((View)firstChild.getChildAt(i)).getLeft());
                 }
             }
         }

     }
     @Override
     public boolean onTouchEvent(MotionEvent ev) {
         switch (ev.getAction()) {
         case MotionEvent.ACTION_DOWN:
             downX = (int) ev.getX();
             break;
         case MotionEvent.ACTION_MOVE:{

         }break;
         case MotionEvent.ACTION_UP:
         case MotionEvent.ACTION_CANCEL:{
             if( Math.abs((ev.getX() - downX)) > getWidth() / 4){
                 if(ev.getX() - downX > 0){
                     smoothScrollToPrePage();
                 }else{
                     smoothScrollToNextPage();
                 }
             }else{
                 smoothScrollToCurrent();
             }
             return true;
         }
         }
         return super.onTouchEvent(ev);
     }

     private void smoothScrollToCurrent() {
         smoothScrollTo(pointList.get(currentPage), 0);
     }

     private void smoothScrollToNextPage() {
         if(currentPage < subChildCount - 1){
             currentPage++;
             smoothScrollTo(pointList.get(currentPage), 0);
         }
     }

     private void smoothScrollToPrePage() {
         if(currentPage > 0){
             currentPage--;
             smoothScrollTo(pointList.get(currentPage), 0);
         }
     }
     /**
      * 下一页
      */
     public void nextPage(){
         smoothScrollToNextPage();
     }
     /**
      * 上一页
      */
     public void prePage(){
         smoothScrollToPrePage();
     }
     /**
      * 跳转到指定的页面
      * @param page
      * @return
      */
     public boolean gotoPage(int page){
         if(page > 0 && page < subChildCount - 1){
             smoothScrollTo(pointList.get(page), 0);
             currentPage = page;
             return true;
         }
         return false;
     }
 }

源代码：http://download.csdn.net/detail/wangwangheng/6537043