现在很多应用都在第一次启动时提供一个简要的介绍,以左右滑动的效果来介绍应用的使用和基本情况。下面将实现一个简单的Demo
首先到SDK的extra目录下找到android-support-v4.jar
首先看一下工程结构:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<android.support.v4.view.ViewPager
android:id="@+id/guidePages"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<LinearLayout
android:id="@+id/viewGroup"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_marginBottom="15dp"
android:gravity="center_horizontal"
android:orientation="horizontal" >
</LinearLayout>
</RelativeLayout>
</FrameLayout>
然后新建page1.xml文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ImageView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/a" >
</ImageView>
</LinearLayout>
page2.xml、page3.xml一样,只要改变图片路径就行
然后编辑Activity
public class ViewPagerActivity extends Activity {
private ViewPager viewPager;
private ArrayList<View> pageViews;
private ViewGroup main;
private ViewGroup group;
private ImageView imageView;
private ImageView[] imageViews;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);
LayoutInflater inflater = getLayoutInflater();
pageViews = new ArrayList<View>();
pageViews.add(inflater.inflate(R.layout.page1, null));
pageViews.add(inflater.inflate(R.layout.page2, null));
pageViews.add(inflater.inflate(R.layout.page3, null));
imageViews = new ImageView[pageViews.size()];
main = (ViewGroup)inflater.inflate(R.layout.main, null);
//group是底部导航小圆点的布局
group = (ViewGroup)main.findViewById(R.id.viewGroup);
viewPager = (ViewPager)main.findViewById(R.id.guidePages);
for (int i = 0; i < pageViews.size(); i++) {
imageView = new ImageView(ViewPagerActivity.this);
imageView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));
imageViews[i] = imageView;
if (i == 0) {
//默认选中第一张图片
imageViews[i].setBackgroundResource(R.drawable.indicator_f);
} else {
imageViews[i].setBackgroundResource(R.drawable.indicator);
}
group.addView(imageViews[i]);
}
setContentView(main);
viewPager.setAdapter(new ViewPagerAdapter());
viewPager.setOnPageChangeListener(new ViewPagerChangeListener());
}
class ViewPagerAdapter extends PagerAdapter{
@Override
public int getCount() {
return pageViews.size();
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
@Override
public void destroyItem(View arg0, int arg1, Object arg2) {
((ViewPager) arg0).removeView(pageViews.get(arg1));
}
@Override
public Object instantiateItem(View arg0, int arg1) {
((ViewPager) arg0).addView(pageViews.get(arg1));
return pageViews.get(arg1);
}
}
class ViewPagerChangeListener 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 position) {
for (int i = 0; i < imageViews.length; i++) {
imageViews[position].setBackgroundResource(R.drawable.indicator_f);
if (position != i) {
imageViews[i].setBackgroundResource(R.drawable.indicator);
}
}
}
}
}
运行,效果图如下,不是很美观,实际使用替换图片就行,需要源码的童鞋可以联系我。我的新浪微博 唐韧_Ryan