Android重写HorizontalScrollView模仿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

 1 <?xml version="1.0" encoding="utf-8"?> 2 <com.example.testxinye.MyScrollView  3     xmlns:android="http://schemas.android.com/apk/res/android" 4     android:layout_width="fill_parent" 5     android:layout_height="fill_parent" 6     > 7     <LinearLayout  8         android:id="@+id/container" 9         android:layout_width="match_parent"10         android:layout_height="match_parent"11         android:orientation="horizontal" >12         13     </LinearLayout>14 </com.example.testxinye.MyScrollView>

Activity类：TestActivity.java

 1 package com.example.testxinye; 2  3 import android.app.Activity; 4 import android.graphics.Color; 5 import android.os.Bundle; 6 import android.util.DisplayMetrics; 7 import android.widget.ImageView; 8 import android.widget.ImageView.ScaleType; 9 import android.widget.LinearLayout;10 import android.widget.LinearLayout.LayoutParams;11 /**12  * 13  * @author xinye14  *15  */16 public class TestActivity extends Activity {17     private LinearLayout mContainer = null;18     @Override19     protected void onCreate(Bundle savedInstanceState) {20         // TODO Auto-generated method stub21         super.onCreate(savedInstanceState);22         setContentView(R.layout.activity_test);23         24         mContainer = (LinearLayout) findViewById(R.id.container);25         26         LayoutParams params = new LayoutParams(getWinWidth(), getWinHeight());27         28         ImageView imageView1 = new ImageView(this);29         imageView1.setLayoutParams(params);30         imageView1.setImageResource(R.drawable.call_show_medal5);31         imageView1.setScaleType(ScaleType.CENTER);32         mContainer.addView(imageView1);33         34         ImageView imageView2 = new ImageView(this);35         imageView2.setLayoutParams(params);36         imageView2.setImageResource(R.drawable.call_show_medal1);37         imageView2.setScaleType(ScaleType.CENTER);38         imageView2.setBackgroundColor(Color.RED);39         mContainer.addView(imageView2);40         41         ImageView imageView3 = new ImageView(this);42         imageView3.setLayoutParams(params);43         imageView3.setImageResource(R.drawable.call_show_medal2);44         imageView3.setScaleType(ScaleType.CENTER);45         imageView3.setBackgroundColor(Color.GRAY);46         mContainer.addView(imageView3);47         48         49         ImageView imageView4 = new ImageView(this);50         imageView4.setLayoutParams(params);51         imageView4.setImageResource(R.drawable.call_show_medal3);52         imageView4.setScaleType(ScaleType.CENTER);53         imageView4.setBackgroundColor(Color.BLUE);54         mContainer.addView(imageView4);55         56         57         ImageView imageView5 = new ImageView(this);58         imageView5.setLayoutParams(params);59         imageView5.setImageResource(R.drawable.call_show_medal4);60         imageView5.setScaleType(ScaleType.CENTER);61         imageView5.setBackgroundColor(Color.GREEN);62         mContainer.addView(imageView5);63         64         65         66     }67     68     @Override69     protected void onResume() {70 //        ((MyScrollView)mContainer.getParent()).init();71         super.onResume();72     }73     74     private int getWinWidth(){75         DisplayMetrics dm = new DisplayMetrics();76         //获取屏幕信息77         getWindowManager().getDefaultDisplay().getMetrics(dm);78         return dm.widthPixels;79     }80     private int getWinHeight(){81         DisplayMetrics dm = new DisplayMetrics();82         //获取屏幕信息83         getWindowManager().getDefaultDisplay().getMetrics(dm);84         return dm.heightPixels;85     }86 }

重写的HorizontalScrollView：MyScrollView.java

  1 package com.example.testxinye;  2   3 import java.util.ArrayList;  4   5 import android.content.Context;  6 import android.util.AttributeSet;  7 import android.view.MotionEvent;  8 import android.view.View;  9 import android.view.ViewGroup; 10 import android.widget.HorizontalScrollView; 11 /** 12  *  13  * @author XINYE 14  * 15  */ 16 public class MyScrollView extends HorizontalScrollView { 17     private int subChildCount = 0; 18     private ViewGroup firstChild = null; 19     private int downX = 0; 20     private int currentPage = 0; 21     private ArrayList<Integer> pointList = new ArrayList<Integer>(); 22      23     public MyScrollView(Context context, AttributeSet attrs, int defStyle) { 24         super(context, attrs, defStyle); 25         init(); 26     } 27  28  29     public MyScrollView(Context context, AttributeSet attrs) { 30         super(context, attrs); 31         init(); 32     } 33  34     public MyScrollView(Context context) { 35         super(context); 36         init(); 37     } 38     private void init() { 39         setHorizontalScrollBarEnabled(false); 40     } 41     @Override 42     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 43         super.onMeasure(widthMeasureSpec, heightMeasureSpec); 44         receiveChildInfo(); 45     } 46     public void receiveChildInfo() { 47          48         firstChild = (ViewGroup) getChildAt(0); 49         if(firstChild != null){ 50             subChildCount = firstChild.getChildCount(); 51             for(int i = 0;i < subChildCount;i++){ 52                 if(((View)firstChild.getChildAt(i)).getWidth() > 0){ 53                     pointList.add(((View)firstChild.getChildAt(i)).getLeft()); 54                 } 55             } 56         } 57  58     } 59     @Override 60     public boolean onTouchEvent(MotionEvent ev) { 61         switch (ev.getAction()) { 62         case MotionEvent.ACTION_DOWN: 63             downX = (int) ev.getX(); 64             break; 65         case MotionEvent.ACTION_MOVE:{ 66              67         }break; 68         case MotionEvent.ACTION_UP: 69         case MotionEvent.ACTION_CANCEL:{ 70             if( Math.abs((ev.getX() - downX)) > getWidth() / 4){ 71                 if(ev.getX() - downX > 0){ 72                     smoothScrollToPrePage(); 73                 }else{ 74                     smoothScrollToNextPage(); 75                 } 76             }else{             77                 smoothScrollToCurrent(); 78             } 79             return true; 80         } 81         } 82         return super.onTouchEvent(ev); 83     } 84  85     private void smoothScrollToCurrent() { 86         smoothScrollTo(pointList.get(currentPage), 0); 87     } 88  89     private void smoothScrollToNextPage() { 90         if(currentPage < subChildCount - 1){ 91             currentPage++; 92             smoothScrollTo(pointList.get(currentPage), 0); 93         } 94     } 95  96     private void smoothScrollToPrePage() { 97         if(currentPage > 0){             98             currentPage--; 99             smoothScrollTo(pointList.get(currentPage), 0);100         }101     }102     /**103      * 下一页104      */105     public void nextPage(){106         smoothScrollToNextPage();107     }108     /**109      * 上一页110      */111     public void prePage(){112         smoothScrollToPrePage();113     }114     /**115      * 跳转到指定的页面116      * @param page117      * @return118      */119     public boolean gotoPage(int page){120         if(page > 0 && page < subChildCount - 1){121             smoothScrollTo(pointList.get(page), 0);122             currentPage = page;123             return true;124         }125         return false;126     }127 }

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