这是谷歌官方给我们提供的一个兼容低版本安卓设备的软件包,里面包囊了只有在安卓3.0以上可以使用的api。而viewpager就是其中之一利用它,我们可以做很多事情,从最简单的导航,到页面菜单等等。那如何使用它呢,与LisstView类似,我们也需要一个适配器,他就是PagerAdapter。看一个简单的例子:
main.xml
<?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" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<include layout="@layout/item_header" />
<android.support.v4.view.ViewPager
android:id="@+id/guidePages"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</LinearLayout>
<!-- 指引图标 -->
<LinearLayout
android:id="@+id/viewGroup"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_marginBottom="40dp"
android:gravity="center_horizontal"
android:orientation="horizontal" >
</LinearLayout>
</FrameLayout>
item01:
<?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" >
<LinearLayout
android:id="@+id/linearLayout02"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/divider_horizontal_line"
android:orientation="vertical" />
<ImageView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/feature_guide_0" />
<LinearLayout
android:id="@+id/linearLayout2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/bg"
android:orientation="vertical" >
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="30px"
android:background="@drawable/divider_horizontal_line"
android:orientation="vertical" />
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingLeft="30px"
android:paddingRight="30px"
android:text="@string/text1"
android:textColor="#000000" />
</LinearLayout>
</LinearLayout>
MainActivity:
package com.ly.test;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;
/**
* Android实现左右滑动指引效果
*
* @Description: Android实现左右滑动指引效果
*
*/
public class GuideViewTestActivity extends Activity {
private ViewPager viewPager;
private ArrayList<View> pageViews;
private ImageView imageView;
private ImageView[] imageViews;
private ViewGroup main;// 包裹滑动图片LinearLayout
private ViewGroup group;// 包裹小圆点的LinearLayout
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
LayoutInflater inflater = getLayoutInflater();
pageViews = new ArrayList<View>();
pageViews.add(inflater.inflate(R.layout.item05, null));
pageViews.add(inflater.inflate(R.layout.item06, null));
pageViews.add(inflater.inflate(R.layout.item01, null));
pageViews.add(inflater.inflate(R.layout.item02, null));
pageViews.add(inflater.inflate(R.layout.item03, null));
pageViews.add(inflater.inflate(R.layout.item04, null));
// 有几个布局页面就有几个圆点图片
imageViews = new ImageView[pageViews.size()];
main = (ViewGroup) inflater.inflate(R.layout.main, null);
viewPager = (ViewPager) main.findViewById(R.id.guidePages);
group = (ViewGroup) main.findViewById(R.id.viewGroup);
// 通过for循环设置圆点图片的布局
for (int i = 0; i < pageViews.size(); i++) {
imageView = new ImageView(GuideViewTestActivity.this);
imageView.setLayoutParams(new LayoutParams(20, 20));
imageView.setPadding(20, 0, 20, 0);
imageViews[i] = imageView;
if (i == 0) {
// 默认选中第一张图片
imageViews[i]
.setBackgroundResource(R.drawable.page_indicator_focused);
} else {
imageViews[i].setBackgroundResource(R.drawable.page_indicator);
}
group.addView(imageViews[i]);
}
setContentView(main);
viewPager.setAdapter(new GuidePageAdapter());
viewPager.setOnPageChangeListener(new GuidePageChangeListener());
}
// 指引页面数据适配器
class GuidePageAdapter extends PagerAdapter {
@Override
public int getCount() {
return pageViews.size();
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
@Override
public int getItemPosition(Object object) {
return super.getItemPosition(object);
}
@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);
}
@Override
public void restoreState(Parcelable arg0, ClassLoader arg1) {
}
@Override
public Parcelable saveState() {
return null;
}
@Override
public void startUpdate(View arg0) {
}
@Override
public void finishUpdate(View arg0) {
}
}
// 指引页面更改事件监听器
class GuidePageChangeListener implements OnPageChangeListener {
@Override
public void onPageScrollStateChanged(int arg0) {
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageSelected(int arg0) {
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);
}
}
}
}
}
没有列出所有的代码,详见附件