ViewPager—01引导页的制作

布局文件

<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"
    tools:context="${relativePackage}.${activityClass}" >

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

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="20dp" >

        <LinearLayout
            android:id="@+id/ll_points"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal" >
        </LinearLayout>

        <View
            android:id="@+id/view_white"
            android:layout_width="10dp"
            android:layout_height="10dp"
            android:background="@drawable/white_point" />
    </RelativeLayout>

</RelativeLayout>

相关代码 

 public class MainActivity extends Activity {

     private ViewPager mViewPager;
     private int[] ids = {R.drawable.a1,R.drawable.a2,R.drawable.a3};
     private List<ImageView> mImageViews;
     private MyPagerAdapter mPagerAdapter;
     private LinearLayout mLlPoints;
     private View mViewPoint;

     private int dis_left; //白点距离左边的距离
     private int dis_pp; //两个点之间的距离

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         requestWindowFeature(Window.FEATURE_NO_TITLE);
         setContentView(R.layout.activity_main);

         initView();
         initData();

         mViewPoint.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

             @Override
             public void onGlobalLayout() {
                 mViewPoint.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                 dis_pp = mLlPoints.getChildAt(1).getLeft() - mLlPoints.getChildAt(0).getLeft();
             }
         });

         mPagerAdapter = new MyPagerAdapter();
         mViewPager.setAdapter(mPagerAdapter);

         mViewPager.addOnPageChangeListener(new OnPageChangeListener() {
             @Override
             public void onPageSelected(int arg0) {

             }

             @Override
             public void onPageScrolled(int arg0,float arg1,int arg2) {
                 //设置白点的移动距离
                 dis_left = (int)((arg0 + arg1) * dis_pp);
                 RelativeLayout.LayoutParams params = (LayoutParams)mViewPoint.getLayoutParams();
                 params.leftMargin = dis_left;
                 mViewPoint.setLayoutParams(params);
             }    

             @Override
             public void onPageScrollStateChanged(int arg0) {

             }
         });

     }

     private void initView() {
         mViewPager = (ViewPager)findViewById(R.id.vp);
         mLlPoints = (LinearLayout)findViewById(R.id.ll_points);
         mViewPoint = findViewById(R.id.view_white);
     }

     private void initData() {

         mImageViews = new ArrayList<ImageView>();

         for (int i = 0;i < ids.length;i++) {

             ImageView iv = new ImageView(this);
             iv.setBackgroundResource(ids[i]);
             mImageViews.add(iv);

             View view = new View(this);
             view.setBackgroundResource(R.drawable.gray_point);
             LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(Utils.dip2px(this,10),
                                                 Utils.dip2px(this,10));
             if(i != 0){
                 params.leftMargin = Utils.dip2px(this,20);
             }
             view.setLayoutParams(params);

             mLlPoints.addView(view);
         }
     }

     class MyPagerAdapter extends PagerAdapter {

         @Override
         public int getCount() {
             return mImageViews.size();
         }

         @Override
         public Object instantiateItem(ViewGroup container,int position) {
             ImageView iv = mImageViews.get(position);
             container.addView(iv);
             return iv;
         }

         @Override
         public boolean isViewFromObject(View arg0,Object arg1) {
             return arg0 == arg1;
         }

         @Override
         public void destroyItem(ViewGroup container,int position,Object object) {
             container.removeView((View)object);
         }

     }
 }

 效果图