Android：使用ViewPager实现左右滑动切换图片加点点

1、引入android-support-v4.jar包，在主布局里加入

< ?xml version="1.0" encoding="utf-8"?>
< RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="@+id/layout"
tools:context="com.zjq.viewpager.MainActivity">

< android.support.v4.view.ViewPager
android:id="@+id/viewPager"
android:layout_width="match_parent"
android:layout_height="wrap_content">
< /android.support.v4.view.ViewPager>

<!-- 点点 -->
< LinearLayout
    android:id="@+id/viewGroup"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_marginBottom="40dp"
    android:gravity="center_horizontal"
    android:orientation="horizontal" >
< /LinearLayout>

< /RelativeLayout >

其他几个子布局都一样 例如 item01 :

< ?xml version="1.0" encoding="utf-8"?>
< LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">

< ImageView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:src="@drawable/view1"
    android:scaleType="centerCrop"
    /></LinearLayout>

2、加载切换内容

3、ViewPager加载适配器PagerAdapter

public class MainActivity extends Activity {
private ViewPager viewPager;
private ArrayList<View> pageview;

private ImageView imageView;
private ImageView[] imageViews;
//包裹点点的LinearLayout
private ViewGroup group;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //设置无标题栏
    requestWindowFeature(Window.FEATURE_NO_TITLE);

    setContentView(R.layout.activity_main);

    viewPager = (ViewPager) findViewById(R.id.viewPager);

    //查找布局文件用LayoutInflater.inflate
    LayoutInflater inflater =getLayoutInflater();
    View view1 = inflater.inflate(R.layout.item01, null);
    View view2 = inflater.inflate(R.layout.item02, null);
    View view3 = inflater.inflate(R.layout.item03, null);
    View view4 = inflater.inflate(R.layout.item04, null);

    //将view装入数组
    pageview =new ArrayList<View>();
    pageview.add(view1);
    pageview.add(view2);
    pageview.add(view3);
    pageview.add(view4);


    group = (ViewGroup)findViewById(R.id.viewGroup);

    //有多少张图就有多少个点点
    imageViews = new ImageView[pageview.size()];
    for(int i =0;i<pageview.size();i++){
        imageView = new ImageView(MainActivity.this);
        imageView.setLayoutParams(new LayoutParams(20,20));
        imageView.setPadding(20, 0, 20, 0);
        imageViews[i] = imageView;

        //默认第一张图显示为选中状态
        if (i == 0) {
            imageViews[i].setBackgroundResource(R.drawable.page_indicator_focused);
        } else {
            imageViews[i].setBackgroundResource(R.drawable.page_indicator_unfocused);
        }

        group.addView(imageViews[i]);

}

    //绑定适配器
    viewPager.setAdapter(mPagerAdapter);
    //绑定监听事件
    viewPager.setOnPageChangeListener(new GuidePageChangeListener());
}

//数据适配器
PagerAdapter mPagerAdapter = new PagerAdapter(){

    @Override
    //获取当前窗体界面数
    public int getCount() {
        // TODO Auto-generated method stub
        return pageview.size();
    }

    @Override
    //断是否由对象生成界面
    public boolean isViewFromObject(View arg0, Object arg1) {
        // TODO Auto-generated method stub
        return arg0==arg1;
    }
    //是从ViewGroup中移出当前View
    public void destroyItem(View arg0, int arg1, Object arg2) {
        ((ViewPager) arg0).removeView(pageview.get(arg1));
    }

    //返回一个对象，这个对象表明了PagerAdapter适配器选择哪个对象放在当前的ViewPager中
    public Object instantiateItem(View arg0, int arg1){
        ((ViewPager)arg0).addView(pageview.get(arg1));
        return pageview.get(arg1);
    }


};



//pageView监听器
class GuidePageChangeListener 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
    //如果切换了，就把当前的点点设置为选中背景，其他设置未选中背景
    public void onPageSelected(int arg0) {
        // TODO Auto-generated method stub
        for(int i=0;i<imageViews.length;i++){
            imageViews[arg0].setBackgroundResource(R.drawable.page_indicator_focused);
            if (arg0 != i) {
                imageViews[i].setBackgroundResource(R.drawable.page_indicator_unfocused);
            }
        }

    }

}  }