Android:如何在ImageView中显示视频缩略图？

Question

我浏览并尝试了多种关于如何将录制的视频显示到 ImageView 的建议，但均未成功。

此代码适用于拍摄图像和显示图像。视频也被录制并保存到手机中，但它不会显示在 ImageView 中。关于如何在此处修改我的代码以使视频显示在 ImageView 中的任何建议？

除了 RESULT_LOAD_VID 部分之外，一切似乎都正常，该部分应该将选定或录制的视频显示到 ImageView。

我收到的错误是:“SkImageDecoder::Factory 返回 null”

据我了解，这意味着无论出于何种原因，所选/录制的视频位置都没有传递到 RESULT_LOAD_VID 部分。

感谢任何帮助。

这是我当前的代码:

public class Media extends AppCompatActivity{

    private static int RESULT_LOAD_IMG = 1;
    private static int RESULT_LOAD_VID = 1;
    String imgDecodableString;
    private String selectedImagePath = "";
    private static final int CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE = 200;
    final private int CAPTURE_IMAGE = 2;
    private Uri fileUri;
    private ImageView mImageView;
    Toolbar toolbar;
    private String imgPath;

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.toolbarmedia, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.camera:
                AlertDialog.Builder builder = new AlertDialog.Builder(Media.this);
                // builder.setTitle("Choose Image Source");
                builder.setItems(new CharSequence[] { "Take a Photo", "Choose from Gallery" },
                        new DialogInterface.OnClickListener() {

                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                switch (which) {
                                    case 0:
                                        Intent intent1 = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                                        intent1.putExtra(MediaStore.EXTRA_OUTPUT, setImageUri());
                                        startActivityForResult(intent1, CAPTURE_IMAGE);
                                        break;
                                    case 1:
                                        // Create intent to Open Image applications like Gallery, Google Photos
                                        Intent galleryIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                                        startActivityForResult(galleryIntent, RESULT_LOAD_IMG);
                                        break;
                                    default:
                                        break;
                                }
                            }
                        });
                builder.show();
                return true;

            case R.id.video:

                AlertDialog.Builder builder2 = new AlertDialog.Builder(Media.this);
                // builder.setTitle("Choose Image Source");
                builder2.setItems(new CharSequence[]{"Take a Video", "Select Video from Phone"},
                        new DialogInterface.OnClickListener() {

                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                switch (which) {
                                    case 0:
                                        //create new Intent
                                        Intent intent_video = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);

                                        fileUri = getOutputMediaFileUri(MEDIA_TYPE_VIDEO);  // create a file to save the video
                                        intent_video.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);  // set the image file name

                                        intent_video.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1); // set the video image quality to high
                                        // start the Video Capture Intent
                                        startActivityForResult(intent_video, CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE);
                                        break;
                                    case 1:
                                        // Create intent to Open Image applications like Gallery, Google Photos
                                        Intent galleryIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Video.Media.EXTERNAL_CONTENT_URI);
                                        startActivityForResult(galleryIntent, RESULT_LOAD_VID);
                                        break;
                                    default:
                                        break;
                                }
                            }
                        });
                builder2.show();
                return true;

            case R.id.mic:

                return true;

            default:
                // If we got here, the user's action was not recognized.
                // Invoke the superclass to handle it.
                return super.onOptionsItemSelected(item);

        }
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_media);
        toolbar = (Toolbar)findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        mImageView = (ImageView) findViewById(R.id.media_display);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        try {
            // When an Image is picked
            if (requestCode == RESULT_LOAD_IMG && resultCode == RESULT_OK && null != data) {
                // Get the Image from data

                Uri selectedImage = data.getData();
                String[] filePathColumn = {MediaStore.Images.Media.DATA};

                // Get the cursor
                Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
                // Move to first row
                cursor.moveToFirst();

                int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                imgDecodableString = cursor.getString(columnIndex);
                cursor.close();
                ImageView imgView = (ImageView) findViewById(R.id.media_display);
                // Set the Image in ImageView after decoding the String
                imgView.setImageBitmap(BitmapFactory.decodeFile(imgDecodableString));

            } else if (requestCode == CAPTURE_IMAGE) {
                selectedImagePath = getImagePath();
                System.out.println("path" + selectedImagePath);
                mImageView.setImageBitmap(decodeStream(selectedImagePath));
            } else if(requestCode == RESULT_LOAD_VID && resultCode == RESULT_OK  && null != data){
                // Get the Image from data
                Uri selectedVideo = data.getData();
                String[] filePathColumn = {MediaStore.Video.Media.DATA};
                 //Get the cursor
               Cursor cursor = getContentResolver().query(selectedVideo, filePathColumn, null, null, null);
                // Move to first row
               cursor.moveToFirst();
                int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                imgDecodableString = cursor.getString(columnIndex);
                cursor.close();
                ImageView vidView = (ImageView) findViewById(R.id.media_display);
                // Set the Image in ImageView after decoding the String
               vidView.setImageBitmap(BitmapFactory.decodeFile(imgDecodableString));
            }else if (requestCode == CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE) {
                if (resultCode == RESULT_OK) {
                    // Video captured and saved to fileUri specified in the Intent
                    Toast.makeText(this, "Video Saved to Phone", Toast.LENGTH_LONG).show();
                } else if (resultCode == RESULT_CANCELED) {
                    // User cancelled the video capture
                } else {

                    // Video capture failed, advise user
                    Toast.makeText(this, "Video capture failed.",
                            Toast.LENGTH_LONG).show();
                    super.onActivityResult(requestCode, resultCode, data);
                }
            }
        } catch (Exception e) {
            Toast.makeText(this, "Something went wrong", Toast.LENGTH_LONG)
                    .show();
        }
    }

    public static final int MEDIA_TYPE_IMAGE = 1;
    public static final int MEDIA_TYPE_VIDEO = 2;

    /** Create a file Uri for saving an image or video */
    private static Uri getOutputMediaFileUri(int type){
        return Uri.fromFile(getOutputMediaFile(type));
    }

    /** Create a File for saving an image or video */
    private static File getOutputMediaFile(int type){
        // To be safe, you should check that the SDCard is mounted
        // using Environment.getExternalStorageState() before doing this.

        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_PICTURES), "MyCameraApp");
        // This location works best if you want the created images to be shared
        // between applications and persist after your app has been uninstalled.

        // Create the storage directory if it does not exist
        if (! mediaStorageDir.exists()){
            if (! mediaStorageDir.mkdirs()){
                Log.d("MyCameraApp", "failed to create directory");
                return null;
            }
        }

        // Create a media file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        File mediaFile;
        if (type == MEDIA_TYPE_IMAGE){
            mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                    "IMG_"+ timeStamp + ".jpg");
        } else if(type == MEDIA_TYPE_VIDEO) {
            mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                    "VID_"+ timeStamp + ".mp4");
        } else {
            return null;
        }

        return mediaFile;
    }

    public Uri setImageUri() {

       File file = new File(Environment.getExternalStorageDirectory(), "image" + new     Date().getTime() + ".png");
        Uri imgUri = Uri.fromFile(file);
       this.imgPath = file.getAbsolutePath();
       return imgUri;
   }


    public String getImagePath() {
        return imgPath;
    }

    public Bitmap decodeStream(String path) {
        try {
            // Decode image size
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeFile(path, o);
            // The new size we want to scale to
            final int REQUIRED_SIZE = 70;

            // Find the correct scale value. It should be the power of
            // 2.
            int scale = 1;
            while (o.outWidth / scale / 2 >= REQUIRED_SIZE
                    && o.outHeight / scale / 2 >= REQUIRED_SIZE)
                scale *= 2;

            // Decode with inSampleSize
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;
            return BitmapFactory.decodeFile(path, o2);
        } catch (Throwable e) {
            e.printStackTrace();
        }
        return null;
    }

}

Answer 1

如果您有视频文件的路径，请使用此方法创建位图格式的缩略图。

public Bitmap createVideoThumbNail(String path){
    return ThumbnailUtils.createVideoThumbnail(path,MediaStore.Video.Thumbnails.MICRO_KIND);
}

并在您的 ImageView 中使用它，例如:-

ivVideoThumbnail.setImageBitmap(createVideoThumbNail(videoPath));