ViewPaper实现轮播广告条

使用V4包中的viewPaper组件自己定义轮播广告条效果。

实现viewpaper的滑动切换和定时自己主动切换效果。

上效果图

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=".MainActivity" >

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpaper"
        android:layout_width="fill_parent"
        android:layout_height="200dp" >
    </android.support.v4.view.ViewPager>

    <LinearLayout
        android:gravity="center_horizontal"
        android:id="@+id/ll_footer"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@id/viewpaper"
        android:background="#33000000"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/tv_imageDesc"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

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

        </LinearLayout>
    </LinearLayout>

</RelativeLayout>

另一个selector

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

    <item android:drawable="@drawable/indicators_now" android:state_enabled="true"></item>
    <item android:drawable="@drawable/indicators_default" android:state_enabled="false"></item>

</selector>

class文件

package com.example.viewpaperdemo;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
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.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MainActivity extends Activity {
  private ViewPager viewpaper;
  private TextView tv_imageDesc;
  private LinearLayout ll_pointGroup;
  private List<ImageView> imageList;
  // 图片资源ID
  private final int[] imageIds = { R.drawable.a, R.drawable.b, R.drawable.c, R.drawable.d, R.drawable.e };

  // 图片标题集合
  private final String[] imageDescriptions = { "巩俐不低俗，我就不能低俗", "扑树又回来啦！再唱经典老歌引万人大合唱", "揭秘北京电影怎样升级", "乐视网TV版大派送",
      "热血屌丝的反杀" };
  protected int lastPosition;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    viewpaper = (ViewPager) findViewById(R.id.viewpaper);
    tv_imageDesc = (TextView) findViewById(R.id.tv_imageDesc);
    ll_pointGroup = (LinearLayout) findViewById(R.id.ll_pointGroup);
    tv_imageDesc.setText(imageDescriptions[0]);

    imageList = new ArrayList<ImageView>();
    for (int i = 0; i < imageIds.length; i++) {
      ImageView imageView = new ImageView(MainActivity.this);
      imageView.setImageResource(imageIds[i]);
      imageList.add(imageView);

      // 加入指示点
      ImageView point = new ImageView(this);
      LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,
          LinearLayout.LayoutParams.WRAP_CONTENT);

      params.rightMargin = 15;
      point.setLayoutParams(params);

      point.setBackgroundResource(R.drawable.doet);
      if (i == 0) {
        point.setEnabled(true);
      } else {
        point.setEnabled(false);
      }
      ll_pointGroup.addView(point);
    }

    // 设置适配器
    viewpaper.setAdapter(new MyAdapter());
    // 初始化位置
    viewpaper.setCurrentItem(Integer.MAX_VALUE / 2 - (Integer.MAX_VALUE / 2 % imageList.size()));
    // 设置监听
    viewpaper.setOnPageChangeListener(new OnPageChangeListener() {
      // 滑动后
      @Override
      public void onPageSelected(int position) {
        position = position % imageList.size();

        // 设置文字描写叙述内容
        tv_imageDesc.setText(imageDescriptions[position]);

        // 改变指示点的状态
        // 把当前点enbale 为true
        ll_pointGroup.getChildAt(position).setEnabled(true);
        // 把上一个点设为false
        ll_pointGroup.getChildAt(lastPosition).setEnabled(false);
        lastPosition = position;
        tv_imageDesc.setText(imageDescriptions[position]);
      }

      // 滑动时
      @Override
      public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
      }

      // 状态改变
      @Override
      public void onPageScrollStateChanged(int state) {
      }
    });
isRunning=true;
   handler.sendEmptyMessageDelayed(0, 2000);

  }
  private boolean isRunning=false;
  Handler handler = new Handler() {

    @Override
    public void handleMessage(Message msg) {
      //滑动到下一页
      viewpaper.setCurrentItem(viewpaper.getCurrentItem() + 1);
      //推断是否存在 是的话就运行
      if (isRunning) {
        handler.sendEmptyMessageDelayed(0, 2000);
      }
    }
  };
  protected void onDestroy() {
    isRunning=false;
    
  };
  public class MyAdapter extends PagerAdapter {

    @Override
    public int getCount() {
      return Integer.MAX_VALUE;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
      return view == object;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
      position = position % imageList.size();
      container.addView(imageList.get(position));
      return imageList.get(position);
    }

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

  }
}