为什么我的 Android ImageView 是空的（通过 Uri、Bitmap 或使用 Picasso 加载）

Question

我有一个片段可以显示图像视频队列。我在 VideoView 中显示的视频效果很好，可以重播，非常棒。但是我放在 ImageView 中的图像看起来是不可见的。我尝试通过 Uri 加载它们，通过读取位图，现在它们已使用 Picasso 设置，并且 none 修复了它。到目前为止，您将在 MultimediaPlayer 中看到的 AssetObtainer 可以处理声音文件和视频，所以我非常怀疑它是否存在图像问题。这是代码：

MultimediaPlayer.java :

public class MultimediaPlayer extends Fragment
{
    VideoView mVideoView;
    ImageView mImageView;
    MultimediaViewModel mMultimediaViewModel;
    Play mPlayThread;
    Activity mActivity;
    AssetObtainer assetObtainer = new AssetObtainer();
    public Long mTutorialId;
    public List<Multimedia> multimedias = new LinkedList<>();

    @Override
    public View onCreateView(@NotNull LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState)
    {
        return inflater.inflate(R.layout.fragment_multimedia_player, container, false);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState)
    {
        mActivity = requireActivity();
        mMultimediaViewModel = new ViewModelProvider(this).get(MultimediaViewModel.class);
        mVideoView = view.findViewById(R.id.video_embed);
        mImageView = view.findViewById(R.id.image_embed);
        getPlayer(0);
    }

    private void getPlayer(int position)
    {
        if(mPlayThread != null) {
            mPlayThread.interrupt();
            position++;
        }
        if(!multimedias.isEmpty()) {
            mPlayThread = new Play(multimedias.get(position));
            mPlayThread.start();
        }
    }

    private class Play extends Thread
    {
        private final Multimedia currentMedia;

        Play(Multimedia media){
            currentMedia = media;
        }

        @Override
        public void run()
        {
            int position = currentMedia.getPosition();
            int displayTime = currentMedia.getDisplayTime();
            boolean loopBool = currentMedia.getLoop();
            if(currentMedia.getType()) {
                mActivity.runOnUiThread(() -> {
                    mImageView.setVisibility(View.VISIBLE);
                    mVideoView.setVisibility(View.GONE);
                    try {
                        Picasso.get().load(assetObtainer.getFileFromAssets(requireContext(), currentMedia.getFullFileName())).into(mImageView);
                    } catch (IOException ignored) {}
                });
                if(displayTime>0) {
                    try {
                        sleep(displayTime);
                        if(!loopBool) multimedias.remove(currentMedia);
                        if(position<multimedias.size()-1) {
                            getPlayer(position);
                        } else getPlayer(0);
                    } catch (InterruptedException e) {
                        mActivity.runOnUiThread(() -> mImageView.setVisibility(View.GONE));
                        interrupt();
                    }
                }
            } else {
                mActivity.runOnUiThread(() -> {
                    mVideoView.setVisibility(View.VISIBLE);
                    mImageView.setVisibility(View.GONE);
                    try {
                        mVideoView.setVideoURI(Uri.fromFile(assetObtainer.getFileFromAssets(requireContext(), currentMedia.getFullFileName())));
                    } catch (IOException ignored) {}
                    if(loopBool && multimedias.size()==1) mVideoView.setOnCompletionListener(v->getPlayer(position-1));
                    mVideoView.start();
                });
            }
        }
    }

    @Override
    public void onPause()
    {
        if(mPlayThread!=null){
            mPlayThread.interrupt();
        }
        super.onPause();
    }
}

activity.xml 文件中片段的床位：

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/layout_multimedia"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toTopOf="@id/active_instructions" />

和片段的 .xml 文件 :

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    tools:context=".tutorial.mediaplayer.MultimediaPlayer">

    <VideoView
        android:id="@+id/video_embed"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/image_embed"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toTopOf="parent"
        android:contentDescription="@string/image_default_no_description" />

</androidx.constraintlayout.widget.ConstraintLayout>

如前所述，视频效果非常好，但无法显示图像。在我必须完全返工之前，我什至会很感激活动扳手的建议。

Answer 1

正如我在其他回答中提到的，它与 ImageView 无关，这是 SQLite 和从数据库加载布尔值的问题。我想要与视频类型相对应的默认 false 是默认的，所以它有效，但由于它不默认为 true，因此图像条件未满足。无论如何，一旦 ImageView 实际上是运行.

，它就会工作

为什么我的 Android ImageView 是空的（通过 Uri、Bitmap 或使用 Picasso 加载）

Why is my Android ImageView empty (loading up through Uri, Bitmap or using Picasso)

java

android

image

imageview

android-fragments