Android 如何解决我的视频缩略图？我的模拟器屏幕上没有显示任何内容

我试图显示我的视频缩略图，但我的模拟器显示一个空屏幕。我不知道我在哪里犯了错误。我正在尝试在我的选项卡主机中显示这些视频缩略图

这是我的代码：

public class video extends Activity {
    //set constants for MediaStore to query, and show videos

    //flag for which one is used for images selection
    private GridView _gallery; 



    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.mavideo);
        //set GridView for gallery
        _gallery = (GridView)findViewById(R.id.sdcard);
        //set default as external/sdcard uri


        //set gallery adapter
        setGalleryAdapter();
    }
    private void setGalleryAdapter() {
        _gallery.setAdapter(new VideoGalleryAdapter(this));
    }

    //
     private class VideoGalleryAdapter extends BaseAdapter {

            private Context mContext;

            public VideoGalleryAdapter(Context c) {
                mContext = c;
            }

            public int getCount() {
                return tabview.videoList.size();
            }

            public Object getItem(int position) {
                return null;
            }

            public long getItemId(int position) {
                return 0;
            }
            public View getView(int position, View convertView, ViewGroup parent) {
                ImageView imageView;
                if (convertView == null) {  // if it's not recycled, initialize some attributes
                    imageView = new ImageView(mContext);
                    imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
                    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                    imageView.setPadding(8, 8, 8, 8);
                } else {
                    imageView = (ImageView) convertView;
                }


                Bitmap bitmap = BitmapFactory.decodeFile(tabview.videoList.get(position));
                imageView.setImageBitmap(bitmap);
                return imageView;

            }
        }
    }

---

什么是tabview.videoList？您可能从BitmapFactory.decodeFile中获取空位图，这就是为什么您看不到任何内容。对如何获取视频缩略图有很好的描述