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

<?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;
    }
}