ViewPage在xml中無法引用的問題

一般viewpage在xml引用如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<android.support.v4.view.ViewPager 
        android:id="@+id/guidePages" 
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content"/> 

</LinearLayout>

這樣做是沒錯的，可是運行時找不到android.support.v4.view.ViewPager，已經匯入了庫檔案android-support-v4.jar，

 

 

原因：未添加源檔案，做法如下：

建立libs檔案夾，將android-support-v4.jar放入到該檔案夾下，右鍵該檔案夾，選擇Build Path->Use as Source Folder，這樣問題就迎刃而解了。

 

 

原因分析：xml檔案引用的是源檔案。

 

附上代碼：

 

main類：

import java.util.ArrayList;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;

public class ViewPageTest2 extends Activity {
    /** Called when the activity is first created. */
   
    private ViewPager viewPager = null;
    private ArrayList<View> listView = null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        initViewPager();
    }
    private void initViewPager() { 
        viewPager = (ViewPager) findViewById(R.id.guidePages); 
        listView = new ArrayList<View>(); 
        LayoutInflater inflater = getLayoutInflater(); 
        listView.add(inflater.inflate(R.layout.one, null)); 
        listView.add(inflater.inflate(R.layout.two, null)); 
        listView.add(inflater.inflate(R.layout.three, null)); 
        viewPager.setAdapter(new MyPagerAdapter(listView)); 
        viewPager.setOnPageChangeListener(new MyPagerChangeListener()); 
         
    } 

}

 

 

MyPagerAdapter類：

 

import java.util.List;

import android.os.Parcelable;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;

public class MyPagerAdapter extends PagerAdapter { 
   
    private List<View> list; 
     
    public MyPagerAdapter(List<View> list) { 
        this.list = list; 
    } 
     
    @Override 
    public void destroyItem(View view, int index, Object arg2) { 
        // TODO Auto-generated method stub 
        ((ViewPager)view).removeView(list.get(index)); 
    } 

    @Override 
    public void finishUpdate(View arg0) { 
        // TODO Auto-generated method stub 
         
    } 

    @Override 
    public int getCount() { 
        // TODO Auto-generated method stub 
        return list.size(); 
    } 

    @Override 
    public Object instantiateItem(View view, int index) { 
        ((ViewPager)view).addView(list.get(index), 0); 
        return list.get(index); 
    } 

    @Override 
    public boolean isViewFromObject(View view, Object object) { 
        // TODO Auto-generated method stub 
        return view == (object); 
    } 

    @Override 
    public void restoreState(Parcelable arg0, ClassLoader arg1) { 
        // TODO Auto-generated method stub 
         
    } 

    @Override 
    public Parcelable saveState() { 
        // TODO Auto-generated method stub 
        return null; 
    } 

    @Override 
    public void startUpdate(View arg0) { 
        // TODO Auto-generated method stub 
         
    } 
     
} 

 

MyPagerChangeListener類：

import android.support.v4.view.ViewPager.OnPageChangeListener;

public class MyPagerChangeListener implements OnPageChangeListener
{

    @Override
    public void onPageScrollStateChanged(int arg0)
    {
        // TODO Auto-generated method stub
       
    }

    @Override
    public void onPageScrolled(int arg0, float arg1, int arg2)
    {
        // TODO Auto-generated method stub
       
    }

    @Override
    public void onPageSelected(int arg0)
    {
        // TODO Auto-generated method stub
       
    }

}