它下面加圆点或者文字描述,其实是ViewPager和textvIEW等等布局在一个文件里面,其它布局通过监听viewPager的变化来动态改变自己而已,就是如此,一点也不神奇。
package com.example.listviewdemo;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.LinearLayout;
/**
*http://blog.youkuaiyun.com/qinyuanpei/article/details/17186319
*这有几篇文章
*
*其实,下面的几个圆点是通过我们相对布局来弄上的,与本身的ViewPager并没有太大关系。
*/
public class BannerActivity extends Activity implements OnClickListener {
ViewPager mViewPager ;
PagerAdapter mPagerAdapter ;
private int[] draws = new int[]{R.drawable.bg,R.drawable.empty_paper_tape,
R.drawable.login_warring_pic,R.drawable.share_tellfriends_bg,R.drawable.splash_bg};
//记录当前选中位置
private int currentIndex;
//底部小图片
private ImageView[] dots ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.banner);
mViewPager = (ViewPager)findViewById(R.id.banner);
initAdapter();
mViewPager.setAdapter(mPagerAdapter);
initListener();
//初始化底部小点
initDots();
}
private void initDots(){
dots = new ImageView[draws.length];
LinearLayout ll = (LinearLayout)findViewById(R.id.ll);
for (int i = 0; i < draws.length; i++) {
dots[i] = (ImageView)ll.getChildAt(i);
dots[i].setEnabled(true);
dots[i].setOnClickListener(this);
dots[i].setTag(i);//设置位置tag,方便取出与当前位置对应
}
currentIndex = 0;
dots[currentIndex].setEnabled(false);
}
private void initAdapter(){
mPagerAdapter = new PagerAdapter() {
@Override
public Object instantiateItem(ViewGroup container, int position) {
ImageView imageView = new ImageView(BannerActivity.this);
imageView.setScaleType(ScaleType.FIT_XY);
imageView.setImageResource(draws[position]);
container.addView(imageView);
return imageView;
}
@Override
public void destroyItem(ViewGroup container, int position,
Object object) {
ImageView imageView = new ImageView(BannerActivity.this);
imageView.setScaleType(ScaleType.FIT_XY);
imageView.setImageResource(draws[position]);
container.removeView(imageView);
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == (View)arg1;
}
@Override
public int getCount() {
return draws == null ? 0 : draws.length;//因为会有一个左右尽头的数据
}
};
}
private void initListener(){
mViewPager.setOnPageChangeListener(new OnPageChangeListener() {
@Override
public void onPageSelected(int pos) {
setCurDot(pos);
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
private void setCurDot(int positon){
if (positon < 0 || positon > draws.length - 1 || currentIndex == positon) {
return;
}
dots[positon] .setEnabled(false);
dots[currentIndex].setEnabled(true);
currentIndex = positon;
}
private void setCurView(int position){
if (position < 0 || position >= draws.length) {
return;
}
mViewPager.setCurrentItem(position);
}
@Override
public void onClick(View v) {
int pos = (Integer)v.getTag();
setCurDot(pos);
setCurView(pos);
}
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<android.support.v4.view.ViewPager
android:id="@+id/banner"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fadingEdge="none"/>
<LinearLayout
android:id="@+id/ll"
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="24.0dip"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:clickable="true"
android:padding="15.0dip"
android:src="@drawable/dot" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:clickable="true"
android:padding="15.0dip"
android:src="@drawable/dot" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:clickable="true"
android:padding="15.0dip"
android:src="@drawable/dot" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:clickable="true"
android:padding="15.0dip"
android:src="@drawable/dot" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:clickable="true"
android:padding="15.0dip"
android:src="@drawable/dot" />
</LinearLayout>
</RelativeLayout>
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:innerRadiusRatio="3"
android:shape="ring"
android:thickness="10dp"
android:useLevel="false" >
<solid android:color="#FF0000" />
<size
android:height="10dp"
android:width="10dp" />
</shape>
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:innerRadiusRatio="3"
android:shape="ring"
android:thickness="10dp"
android:useLevel="false" >
<solid android:color="#0000FF" />
<size
android:height="10dp"
android:width="10dp" />
</shape>
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
<item android:state_enabled="true" android:drawable="@drawable/circlewhite"></item>
<item android:state_enabled="false" android:drawable="@drawable/circleblack"></item>
</selector>