Android 实现图片，视频在同一个item轮播，先展示图片，图片展示1秒暗淡消失，然后播放视频 Java完整代码加布局

以下是一个简单的实现，使用了ViewPager来实现图片和视频的轮播。

1. 布局文件：activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

  <androidx.viewpager.widget.ViewPager
      android:id="@+id/view_pager"
      android:layout_width="match_parent"
      android:layout_height="match_parent" />

</RelativeLayout>

2. 页面布局文件：item_page.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

  <ImageView
      android:id="@+id/image_view"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:scaleType="centerCrop" />

  <VideoView
      android:id="@+id/video_view"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:visibility="gone" />

</RelativeLayout>

3. Java代码：MainActivity.java

public class MainActivity extends AppCompatActivity {

  private ViewPager viewPager;
  private int[] images = {R.drawable.image1, R.drawable.image2, R.drawable.image3};
  private int[] videos = {R.raw.video1, R.raw.video2, R.raw.video3};
  private List<View> pages = new ArrayList<>();
  private int currentPage = 0;

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

    viewPager = findViewById(R.id.view_pager);

    for (int i = 0; i < images.length; i++) {
      View page = LayoutInflater.from(this).inflate(R.layout.item_page, null);
      ImageView imageView = page.findViewById(R.id.image_view);
      VideoView videoView = page.findViewById(R.id.video_view);
      imageView.setImageResource(images[i]);
      videoView.setVideoURI(Uri.parse("android.resource://" + getPackageName() + "/" + videos[i]));
      pages.add(page);
    }

    viewPager.setAdapter(new PagerAdapter() {
      @Override
      public int getCount() {
        return pages.size();
      }

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

      @NonNull
      @Override
      public Object instantiateItem(@NonNull ViewGroup container, int position) {
        View page = pages.get(position);
        container.addView(page);
        return page;
      }

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

    viewPager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
      @Override
      public void onPageSelected(int position) {
        currentPage = position;
        playPage();
      }
    });

    playPage();
  }

  private void playPage() {
    View page = pages.get(currentPage);
    ImageView imageView = page.findViewById(R.id.image_view);
    final VideoView videoView = page.findViewById(R.id.video_view);
    imageView.animate().alpha(0f).setDuration(1000).withEndAction(new Runnable() {
      @Override
      public void run() {
        videoView.setVisibility(View.VISIBLE);
        videoView.start();
      }
    });
  }

}

在MainActivity中，我们初始化了ViewPager，并且为每个页面添加了一个ImageView和一个VideoView。我们使用PagerAdapter来管理页面，当页面被选中时，我们调用playPage()方法来播放页面。在playPage()方法中，我们使用alpha动画来让ImageView逐渐消失，然后将VideoView设置为可见并开始播放视频。