Android如何从图库获取视频文件的缩略图

Question

我需要在列表视图中显示从相册中选择的视频文件。 我已经成功获取了视频文件的uri，但是我无法获取视频文件的缩略图图像。 这是我用于从URI获取视频文件图像的代码，但它会导致应用程序崩溃。 有没有其他方法可以获得视频文件的图像..？如果有其他方法可以实现，请协助我...

public static String getFileMetaData(Context context,String uri){
        Uri queryUri = Uri.parse(uri);
        // Get relevant columns for use later.
        String[] projection = {
                MediaStore.Files.FileColumns._ID,
                MediaStore.Files.FileColumns.DATA,
                MediaStore.Files.FileColumns.DATE_ADDED,
                MediaStore.Files.FileColumns.MEDIA_TYPE,
                MediaStore.Files.FileColumns.MIME_TYPE,
                MediaStore.Files.FileColumns.TITLE
        };
// Return only video and image metadata.
        String selection = MediaStore.Files.FileColumns.MEDIA_TYPE + "="
                + MediaStore.Files.FileColumns.MEDIA_TYPE_IMAGE
                + " OR "
                + MediaStore.Files.FileColumns.MEDIA_TYPE + "="
                + MediaStore.Files.FileColumns.MEDIA_TYPE_VIDEO;

        CursorLoader cursorLoader = new CursorLoader(
                context,
                queryUri,
                projection,
                selection,
                null, // Selection args (none).
                MediaStore.Files.FileColumns.DATE_ADDED + " DESC" // Sort order.
        );

        Cursor cursor = cursorLoader.loadInBackground();
        int columnIndex = cursor.getColumnIndex(MediaStore.Video.Thumbnails.DATA);

        Log.d("MyTag","***************** : " + cursor.getString(columnIndex));

        cursor.close();
        return null;
    }

- Nidheesh

Answer 1

通过一些更改解决了这个问题。实际上，我的问题是我提供的文件路径是错误的。我一直在提供从图库获取的Uri，现在我已经改变了代码来获取Uri中的真实路径，然后将它们应用于ThumbnailUtils来创建缩略图。

Uri uri = Uri.parse(uri);
String mUri = AppUtils.getRealPathFromURI(mActivity,uri,"VIDEO");
mImageSend.setImageBitmap(ThumbnailUtils.createVideoThumbnail(
                            mUri, MediaStore.Video.Thumbnails.FULL_SCREEN_KIND));


public static String getRealPathFromURI(Context context,Uri contentURI,String type) {

        String result  = null;
        try {
            Cursor cursor = context.getContentResolver().query(contentURI, null, null, null, null);
            if (cursor == null) { // Source is Dropbox or other similar local file path
                result = contentURI.getPath();
                Log.d("TAG", "result******************" + result);
            } else {
                cursor.moveToFirst();
                int idx = 0;
                if(type.equalsIgnoreCase("IMAGE")){
                    idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
                }else if(type.equalsIgnoreCase("VIDEO")){
                    idx = cursor.getColumnIndex(MediaStore.Video.VideoColumns.DATA);
                }else if(type.equalsIgnoreCase("AUDIO")){
                    idx = cursor.getColumnIndex(MediaStore.Audio.AudioColumns.DATA);
                }
                result = cursor.getString(idx);
                Log.d("TAG", "result*************else*****" + result);
                cursor.close();
            }
        } catch (Exception e){
            Log.e("TAG", "Exception ",e);
        }
        return result;
    }

- Nidheesh

Answer 2

首先，您需要从视频文件URI获取视频文件的文件路径，然后从文件路径生成视频缩略图。

您可以使用ThumbnailUtils类的createVideoThumbnail方法来获取缩略图，如下所示。

video_imageview.setImageBitmap(ThumbnailUtils.createVideoThumbnail(selectedVideoFilePath, MediaStore.Video.Thumbnails.FULL_SCREEN_KIND));

在这里，selectedVideoFilePath是视频文件的路径。您可以使用此方法获取文件路径。

String selectedVideoFilePath = GetFilePathFromDevice.getPath(this, videoFileUri);

您可以使用GetFilePathFromDevice类从给定的Uri中获取文件路径。

GetFilePathFromDevice.java

@SuppressLint("NewApi")
public final class GetFilePathFromDevice {

    /**
     * Get file path from URI
     *
     * @param context context of Activity
     * @param uri     uri of file
     * @return path of given URI
     */
    public static String getPath(final Context context, final Uri uri) {
        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
        // DocumentProvider
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];
                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {
                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];
                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }
                final String selection = "_id=?";
                final String[] selectionArgs = new String[]{split[1]};
                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        }
        // MediaStore (and general)
        else if ("content".equalsIgnoreCase(uri.getScheme())) {
            // Return the remote address
            if (isGooglePhotosUri(uri))
                return uri.getLastPathSegment();
            return getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }
        return null;
    }

    public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
        Cursor cursor = null;
        final String column = "_data";
        final String[] projection = {column};
        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
            if (cursor != null && cursor.moveToFirst()) {
                final int index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }

    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }

    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }

    public static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri.getAuthority());
    }
}

我希望你能理解并受益于这篇文章！

- Rajesh Jadav