在Android上的XML布局文件中设置视频视图的imageUrl

我有一个从网站下载JSON输入的应用程序，它将URI返回到图片或视频。我可以让MaterialCardView通过ImageView显示图片。我的计划是设置一个覆盖视频视图，只有在特定项目是视频类型时才可见。以下是两个视图的XML：

<ImageView
    android:id="@+id/picture_image"
    android:layout_width="377dp"
    android:layout_height="429dp"
    android:layout_marginBottom="84dp"
    android:adjustViewBounds="true"
    android:contentDescription="@string/nasa_pictures_list_id"
    android:padding="2dp"
    android:scaleType="centerCrop"

    app:imageUrl="@{picture.imgSrcUrl}"
    app:layout_constraintBottom_toTopOf="@+id/picture_title"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.47"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    tools:layout_conversion_absoluteHeight="191dp"
    tools:layout_conversion_absoluteWidth="411dp"
    tools:src="@tools:sample/backgrounds/scenic" />
    <!-- android:visibility="@{picture.image ? View.VISIBLE : View.GONE}"-->

<VideoView
    android:id="@+id/picture_video"
    android:layout_width="377dp"
    android:layout_height="429dp"
    android:layout_marginBottom="84dp"
    android:adjustViewBounds="true"
    android:contentDescription="@string/nasa_pictures_list_id"
    android:padding="2dp"
    android:scaleType="centerCrop"

    app:imageUrl="@{picture.imgSrcUrl}"
    app:layout_constraintBottom_toTopOf="@+id/picture_title"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.47"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    tools:layout_conversion_absoluteHeight="191dp"
    tools:layout_conversion_absoluteWidth="411dp"
    tools:src="@tools:sample/backgrounds/scenic" />
    <!-- android:visibility="@{picture.video ? View.VISIBLE : View.GONE}"-->

我暂时把android:visibility代码注释掉了

我的问题是，VideoView在

app:imageUrl=“@{picture.imgSrcUrl}”

上有一个编译错误，该错误在前面的ImageView上正常工作。错误是：

找不到接受参数类型“java.lang.String”的setter

好吧，我明白了，它不喜欢弦

• 我的问题是它是什么样子的
• 如何在XML布局文件中指定它

---

谢谢page

我得出的结论是，您不能通过XML文件执行此操作。我找不到一个这样做的例子。我所做的是修改我在高级Android培训中的

SampleVideoView

中找到的代码，该培训有效，可以在这里找到<代码>https://github.com/google-developer-training/android-advanced/tree/master/SimpleVideoView

首先，我在我的应用程序中创建了一个Java类，如下所示：

public class VideoViewAdapter {

    private  String VIDEO_SAMPLE =
            "https://images.all-free-download.com/footage_preview/mp4/rocket_launch_cape_caneveral_nasa_535.mp4";


    private Context mContext;
    private VideoView mVideoView;


    // Current playback position (in milliseconds).
    private int mCurrentPosition = 0;

    // Tag for the instance state bundle.
    private static final String PLAYBACK_TIME = "play_time";

    public void initVideo(Context context, VideoView videoView) {
        // Set up the media controller widget and attach it to the video view.
        mVideoView = videoView;
        MediaController controller = new MediaController(context);
        controller.setMediaPlayer(mVideoView);
        mVideoView.setMediaController(controller);
        mContext = context;
    }

    public void initializePlayer(VideoView videoView,String url, int position) {

        if(url!=null) VIDEO_SAMPLE = url;
        if(position!=0) mCurrentPosition = position;
        mVideoView = videoView;
        // Buffer and decode the video sample.
        Uri videoUri = getMedia(VIDEO_SAMPLE);
        mVideoView.setVideoURI(videoUri);

        // Listener for onPrepared() event (runs after the media is prepared).
        mVideoView.setOnPreparedListener(
                new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mediaPlayer) {

                        // Restore saved position, if available.
                        if (mCurrentPosition > 0) {
                            mVideoView.seekTo(mCurrentPosition);
                        } else {
                            // Skipping to 1 shows the first frame of the video.
                            mVideoView.seekTo(1);
                        }

                        // Start playing!
                        mVideoView.start();
                    }
                });

        // Listener for onCompletion() event (runs after media has finished
        // playing).
        mVideoView.setOnCompletionListener(
                new MediaPlayer.OnCompletionListener() {
                    @Override
                    public void onCompletion(MediaPlayer mediaPlayer) {
                        Toast.makeText(mContext,
                                R.string.toast_message,
                                Toast.LENGTH_SHORT).show();

                        // Return the video position to the start.
                        mVideoView.seekTo(0);
                    }
                });
    }


    // Release all media-related resources. In a more complicated app this
    // might involve unregistering listeners or releasing audio focus.
    public void releasePlayer() {
        mVideoView.stopPlayback();
    }

    // Get a Uri for the media sample regardless of whether that sample is
    // embedded in the app resources or available on the internet.
    private Uri getMedia(String mediaName) {
        if (URLUtil.isValidUrl(mediaName)) {
            // Media name is an external URL.
            return Uri.parse(mediaName);
        } else {
            // Media name is a raw resource embedded in the app.

            return Uri.parse("android.resource://" + mContext.getPackageName() +
                    "/raw/" + mediaName);
        }
    }
}

这为我提供了一个视图适配器，我可以在MainActivity的顶部实例化它，如下所示：

public class VideoViewAdapter {

    private  String VIDEO_SAMPLE =
            "https://images.all-free-download.com/footage_preview/mp4/rocket_launch_cape_caneveral_nasa_535.mp4";


    private Context mContext;
    private VideoView mVideoView;


    // Current playback position (in milliseconds).
    private int mCurrentPosition = 0;

    // Tag for the instance state bundle.
    private static final String PLAYBACK_TIME = "play_time";

    public void initVideo(Context context, VideoView videoView) {
        // Set up the media controller widget and attach it to the video view.
        mVideoView = videoView;
        MediaController controller = new MediaController(context);
        controller.setMediaPlayer(mVideoView);
        mVideoView.setMediaController(controller);
        mContext = context;
    }

    public void initializePlayer(VideoView videoView,String url, int position) {

        if(url!=null) VIDEO_SAMPLE = url;
        if(position!=0) mCurrentPosition = position;
        mVideoView = videoView;
        // Buffer and decode the video sample.
        Uri videoUri = getMedia(VIDEO_SAMPLE);
        mVideoView.setVideoURI(videoUri);

        // Listener for onPrepared() event (runs after the media is prepared).
        mVideoView.setOnPreparedListener(
                new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mediaPlayer) {

                        // Restore saved position, if available.
                        if (mCurrentPosition > 0) {
                            mVideoView.seekTo(mCurrentPosition);
                        } else {
                            // Skipping to 1 shows the first frame of the video.
                            mVideoView.seekTo(1);
                        }

                        // Start playing!
                        mVideoView.start();
                    }
                });

        // Listener for onCompletion() event (runs after media has finished
        // playing).
        mVideoView.setOnCompletionListener(
                new MediaPlayer.OnCompletionListener() {
                    @Override
                    public void onCompletion(MediaPlayer mediaPlayer) {
                        Toast.makeText(mContext,
                                R.string.toast_message,
                                Toast.LENGTH_SHORT).show();

                        // Return the video position to the start.
                        mVideoView.seekTo(0);
                    }
                });
    }


    // Release all media-related resources. In a more complicated app this
    // might involve unregistering listeners or releasing audio focus.
    public void releasePlayer() {
        mVideoView.stopPlayback();
    }

    // Get a Uri for the media sample regardless of whether that sample is
    // embedded in the app resources or available on the internet.
    private Uri getMedia(String mediaName) {
        if (URLUtil.isValidUrl(mediaName)) {
            // Media name is an external URL.
            return Uri.parse(mediaName);
        } else {
            // Media name is a raw resource embedded in the app.

            return Uri.parse("android.resource://" + mContext.getPackageName() +
                    "/raw/" + mediaName);
        }
    }
}

现在在科特林：

.
.
.
lateinit var VIDEOADAPTOR: VideoViewAdapter
.
class MainActivity : AppCompatActivity() {



    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        .
        .
        .
        VIDEOADAPTOR = VideoViewAdapter()

然后在布局片段的片段类文件中。我将以下代码放在onBindViewHolder覆盖下的RecyclerView.Adapter类中

class DailyPictureAdapter(val callback: PictureClick) : RecyclerView.Adapter<DailyPictureViewHolder>() {

.
.
.
/**
     * Called by RecyclerView to display the data at the specified position. This method should
     * update the contents of the {@link ViewHolder#itemView} to reflect the item at the given
     * position.
     */
    override fun onBindViewHolder(holder: DailyPictureViewHolder, position: Int) {
        holder.viewDataBinding.also {
            it.picture = pictures[position]
            it.pictureCallback = callback
            if(pictures[position].isVideo) {
                VIDEOADAPTOR.initVideo(context, it.pictureVideo)
                VIDEOADAPTOR.initializePlayer(it.pictureVideo,it.pictureVideo.pictures[position].imgSrcUrl, 0)

            }
        }
        holder.itemView.setOnClickListener{ callback.onClick(pictures[position])}

    }

}

class DailyPictureAdapter（val回调：PictureClick）：RecyclerView.Adapter（）{
.
.
.
/**
*由RecyclerView调用以在指定位置显示数据。此方法应
*更新{@link ViewHolder#itemView}的内容以反映给定位置的项目
*位置。
*/
覆盖BindViewHolder（holder:DailyPictureView文件夹，位置：Int）{
holder.viewDataBinding.allow{
it.picture=图片[位置]
it.pictureCallback=回调
如果（图片[位置].isVideo）{
VideoAdapter.initVideo（上下文，it.pictureVideo）
VideoAdapter.initializePlayer（it.pictureVideo，it.pictureVideo.pictures[position].imgSrcUrl，0）
}
}
holder.itemView.setOnClickListener{callback.onClick（pictures[position]）}
}
}

这起到了作用，它在视频视图中播放视频，作为回收器视图的一部分。很好，但是

我的问题是内存使用。对于我的应用程序，一次有15到25条记录，其中只有几条是视频，这并不存在问题。然而，如果这是一个视频列表，我想我们会很快发现内存问题

我找不到一个好的地方来发布资源，因为它们滚动到了视图之外。如果有人能对此发表评论，请发表评论