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;

    }

  }

}