如何播放从 SD 卡中选择的视频？

Question

    public class VideoDemo extends Activity {
        private VideoView video;
        private MediaController ctlr;

        File clip=new File(Environment.getExternalStorageDirectory();
        {

                if (clip.exists()) {
                video=(VideoView)findViewById(R.id.videoGrdView);
                video.setVideoPath(clip.getAbsolutePath());

                ctlr=new MediaController(this);
                ctlr.setMediaPlayer(video);
                video.setMediaController(ctlr);
                video.requestFocus();
                video.start();
        }
   }};
}

因此，

我的 SD 卡上的所有视频都有一个 VideoGrdView，可以在单独的活动中显示，现在我需要知道如何从网格中单击视频并使其通过此媒体播放器播放。任何帮助表示赞赏。

    public class Menus extends Activity {
//set constants for MediaStore to query, and show videos
private final static Uri MEDIA_EXTERNAL_CONTENT_URI =      
    MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
private final static String _ID = MediaStore.Video.Media._ID;
private final static String MEDIA_DATA = MediaStore.Video.Media.DATA;
//flag for which one is used for images selection
private GridView _gallery; 
private Cursor _cursor;
private int _columnIndex;
private int[] _videosId;
private Uri _contentUri;


protected Context _context;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    _context = getApplicationContext();
    _gallery = (GridView) findViewById(R.id.videoGrdVw);
    //set default as external/sdcard uri
    _contentUri = MEDIA_EXTERNAL_CONTENT_URI;
    //initialize the videos uri 
    //showToast(_contentUri.getPath());
    initVideosId();
    //set gallery adapter
    setGalleryAdapter();
}
private void setGalleryAdapter() {
    _gallery.setAdapter(new VideoGalleryAdapter(_context));
    _gallery.setOnItemClickListener(_itemClickLis);

}
private AdapterView.OnItemClickListener _itemClickLis = new OnItemClickListener() 
{
    public void onItemClick(AdapterView<?> parent, View v, int position, long id) 
    {
        // Now we want to actually get the data location of the file
        String [] proj={MEDIA_DATA};
        // We request our cursor again
        _cursor = managedQuery(_contentUri,
                proj, // Which columns to return
                null,       // WHERE clause; which rows to return (all rows)
                null,       // WHERE clause selection arguments (none)
                null); // Order-by clause (ascending by name)
        // We want to get the column index for the data uri
        int count = _cursor.getCount();
        //
        _cursor.moveToFirst();
        //
        _columnIndex = _cursor.getColumnIndex(MEDIA_DATA);
        // Lets move to the selected item in the cursor
        _cursor.moveToPosition(position);
        startActivity(new Intent("com.ave"));
        }
};
private void initVideosId() {
    try
    {
        //Here we set up a string array of the thumbnail ID column we want to get back
        String [] proj={_ID};
        // Now we create the cursor pointing to the external thumbnail store
        _cursor = managedQuery(_contentUri,
                proj, // Which columns to return
                null,       // WHERE clause; which rows to return (all rows)
                null,       // WHERE clause selection arguments (none)
                null); // Order-by clause (ascending by name)
        int count= _cursor.getCount();
        // We now get the column index of the thumbnail id
        _columnIndex = _cursor.getColumnIndex(_ID);
        //initialize 
        _videosId = new int[count];
        //move position to first element
        _cursor.moveToFirst();          
        for(int i=0;i<count;i++)
        {           
            int id = _cursor.getInt(_columnIndex);
            //
            _videosId[i]= id;
            //
            _cursor.moveToNext();
            //
        }
    }catch(Exception ex)
    {

    }

}


//
private class VideoGalleryAdapter extends BaseAdapter
{
    public VideoGalleryAdapter(Context c) 
    {
        _context = c;
    }
    public int getCount() 
    {
        return _videosId.length;
    }
    public Object getItem(int position) 
    {
        return position;
    }
    public long getItemId(int position) 
    {
        return position;
    }
    public View getView(int position, View convertView, ViewGroup parent) 
    {
        ImageView imgVw= new ImageView(_context);;
        try
        {
            if(convertView!=null)
            {
                imgVw= (ImageView) convertView;
            }
            imgVw.setImageBitmap(getImage(_videosId[position]));
            imgVw.setLayoutParams(new GridView.LayoutParams(96, 96));
            imgVw.setPadding(8, 8, 8, 8);
        }
        catch(Exception ex)
        {
            System.out.println("StartActivity:getView()-135: ex " + ex.getClass() +", "+ ex.getMessage());
        }
        return imgVw;
    }

    // Create the thumbnail on the fly
    private Bitmap getImage(int id) {
        Bitmap thumb = MediaStore.Video.Thumbnails.getThumbnail(
                getContentResolver(),
                id, MediaStore.Video.Thumbnails.MICRO_KIND, null);
        return thumb;
    }

}

}

Answer 1

Gallery 的工作方式与 ListView 几乎相同。在 onItemClick 方法中，您应该能够知道单击了哪个特定项目。获取该项目的 Uri/绝对路径，并将该信息传递给下一个活动。

在 VideoDemo 类中，提取此 Uri/路径并将其设置为 VideoView。