Android实现图片文字轮播特效

本文实例讲解了Android实现图片文字轮播特效的详细代码，分享给大家供大家参考，具体内容如下

图片轮播是类似知乎日报上的一个轮播效果，如下图。

好了直接进入正题，首先是出示一下效果：

MainActivity：

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit; 

import android.os.Bundle;
import android.app.Activity;
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.ImageView.ScaleType;
import android.widget.LinearLayout;
import android.widget.TextView; 

public class MainActivity extends Activity { 

  //viewpager
  private ViewPager view_pager;
  private LinearLayout ll_dotGroup;
  private TextView newsTitle;
  private int imgResIds[] = new int[]{R.drawable.a, R.drawable.b,
      R.drawable.c, R.drawable.d, R.drawable.b};
  //存储5张图片
  private String textview[]=new String[]{"12412515125","fawfafawf"
      ,"13f1f12f211","1251f1f12","1t1f12f121"};
  //存储5个目录
  private int curIndex = 0;
  //用来记录当前滚动的位置
  PicsAdapter picsAdapter; 

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main); 

    setViewPager(); 

  } 

  private void setViewPager() { 

    newsTitle=(TextView)findViewById(R.id.NewsTitle);
    view_pager = (ViewPager) findViewById(R.id.view_pager);
    ll_dotGroup = (LinearLayout) findViewById(R.id.dotgroup); 

    picsAdapter = new PicsAdapter(); // 创建适配器
    picsAdapter.setData(imgResIds);
    view_pager.setAdapter(picsAdapter); // 设置适配器 

    view_pager.setOnPageChangeListener(new MyPageChangeListener()); //设置页面切换监听器 

    initPoints(imgResIds.length); // 初始化图片小圆点
    startAutoScroll(); // 开启自动播放
  } 

  // 初始化图片轮播的小圆点和目录
  private void initPoints(int count) {
    for (int i = 0; i < count; i++) { 

      ImageView iv = new ImageView(this);
      LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
          20, 20);
      params.setMargins(0, 0, 20, 0);
      iv.setLayoutParams(params); 

      iv.setImageResource(R.drawable.dot1); 

      ll_dotGroup.addView(iv); 

    }
    ((ImageView) ll_dotGroup.getChildAt(curIndex))
        .setImageResource(R.drawable.dot2); 

    newsTitle.setText(textview[curIndex]);
  } 

  // 自动播放
  private void startAutoScroll() {
    ScheduledExecutorService scheduledExecutorService = Executors
        .newSingleThreadScheduledExecutor();
    // 每隔4秒钟切换一张图片
    scheduledExecutorService.scheduleWithFixedDelay(new ViewPagerTask(), 5,
        4, TimeUnit.SECONDS);
  } 

  // 切换图片任务
  private class ViewPagerTask implements Runnable {
    @Override
    public void run() { 

      runOnUiThread(new Runnable() {
        @Override
        public void run() {
          int count = picsAdapter.getCount();
          view_pager.setCurrentItem((curIndex + 1) % count);
        }
      });
    }
  } 

  // 定义ViewPager控件页面切换监听器
  class MyPageChangeListener implements OnPageChangeListener { 

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

    @Override
    public void onPageSelected(int position) {
      ImageView imageView1 = (ImageView) ll_dotGroup.getChildAt(position);
      ImageView imageView2 = (ImageView) ll_dotGroup.getChildAt(curIndex);
      if (imageView1 != null) {
        imageView1.setImageResource(R.drawable.dot2);
      }
      if (imageView2 != null) {
        imageView2.setImageResource(R.drawable.dot1);
      }
      curIndex = position;
      newsTitle.setText(textview[curIndex]); 

    } 

    boolean b = false; 

    @Override
    public void onPageScrollStateChanged(int state) {
      //这段代码可不加，主要功能是实现切换到末尾后返回到第一张
      switch (state) {
        case 1:// 手势滑动
          b = false;
          break;
        case 2:// 界面切换中
          b = true;
          break;
        case 0:// 滑动结束，即切换完毕或者加载完毕
          // 当前为最后一张，此时从右向左滑，则切换到第一张
          if (view_pager.getCurrentItem() == view_pager.getAdapter()
              .getCount() - 1 && !b) {
            view_pager.setCurrentItem(0);
          }
          // 当前为第一张，此时从左向右滑，则切换到最后一张
          else if (view_pager.getCurrentItem() == 0 && !b) {
            view_pager.setCurrentItem(view_pager.getAdapter()
                .getCount() - 1);
          }
          break; 

        default:
          break;
      }
    }
  } 

  // 定义ViewPager控件适配器
  class PicsAdapter extends PagerAdapter { 

    private List<ImageView> views = new ArrayList<ImageView>(); 

    @Override
    public int getCount() {
      if (views == null) {
        return 0;
      }
      return views.size();
    } 

    public void setData(int[] imgResIds) {
      for (int i = 0; i < imgResIds.length; i++) {
        ImageView iv = new ImageView(MainActivity.this);
        ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(
            ViewGroup.LayoutParams.MATCH_PARENT,
            ViewGroup.LayoutParams.MATCH_PARENT);
        iv.setLayoutParams(params);
        iv.setScaleType(ScaleType.FIT_XY);
        //设置ImageView的属性
        iv.setImageResource(imgResIds[i]);
        views.add(iv);
      }
    } 

    public Object getItem(int position) {
      if (position < getCount())
        return views.get(position);
      return null;
    } 

    @Override
    public boolean isViewFromObject(View arg0, Object arg1) {
      return arg0 == arg1;
    } 

    @Override
    public void destroyItem(View container, int position, Object object) { 

      if (position < views.size())
        ((ViewPager) container).removeView(views.get(position));
    } 

    @Override
    public int getItemPosition(Object object) {
      return views.indexOf(object);
    } 

    @Override
    public Object instantiateItem(View container, int position) {
      if (position < views.size()) {
        final ImageView imageView = views.get(position);
        ((ViewPager) container).addView(imageView);
        return views.get(position);
      }
      return null;
    } 

  } 

}

activity_main:

<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" > 

  <RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="150dp"
    android:layout_marginBottom="5dp"
    android:orientation="vertical" > 

    <android.support.v4.view.ViewPager
      android:id="@+id/view_pager"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_gravity="center" >
    </android.support.v4.view.ViewPager> 

    <RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_alignParentBottom="true"
      android:background="@drawable/focus_bg"
      >
      <TextView
        android:id="@+id/NewsTitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="我校交换生演讲比赛夺冠 美国华盛本大学万里发来贺电"
        android:paddingTop="10dp"
        android:paddingBottom="8dp"
        android:paddingLeft="10dp"
        android:paddingRight="100dp"
        android:textSize="15sp"
        android:textColor="#fff"/>
    <LinearLayout
      android:id="@+id/dotgroup"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentRight="true"
      android:paddingTop="23dp"
      android:paddingRight="10dp"
      android:gravity="center"
      android:layout_marginBottom="15dp"
      android:orientation="horizontal" >
    </LinearLayout>
  </RelativeLayout>
  </RelativeLayout> 

</RelativeLayout>

以上就是关于Android实现图片文字轮播特效讲解，希望对大家的学习有所帮助。