android - 从真实路径获取Uri

Question

我有一个文件的真实路径，如“file:///mnt/sdcard/3dphoto/temp19.jps”，我怎样才能得到像“content://media/external/images/media/1”这样的uri？

Answer 1

将您的“file://...”转换为文件路径，使用以下代码找到项目的 id，然后将其附加到提供者 URI。此外，根据文件扩展名，使用正确的提供程序(例如 MediaStore.Video.Media.EXTERNAL_CONTENT_URI 或 MediaStore.Image.Media.EXTERNAL_CONTENT_URI)

/**
 * Given a media filename, returns it's id in the media content provider
 *
 * @param providerUri
 * @param appContext
 * @param fileName
 * @return
 */
public long getMediaItemIdFromProvider(Uri providerUri, Context appContext, String fileName) {
    //find id of the media provider item based on filename
    String[] projection = { MediaColumns._ID, MediaColumns.DATA };
    Cursor cursor = appContext.getContentResolver().query(
            providerUri, projection,
            MediaColumns.DATA + "=?", new String[] { fileName },
            null);
    if (null == cursor) {
        Log.d(TAG_LOG, "Null cursor for file " + fileName);
        return ITEMID_NOT_FOUND;
    }
    long id = ITEMID_NOT_FOUND;
    if (cursor.getCount() > 0) {
        cursor.moveToFirst();
        id = cursor.getLong(cursor.getColumnIndexOrThrow(BaseColumns._ID));
    }
    cursor.close();
    return id;
}

有时，在将一个媒体文件添加到设备的存储后，MediaProvider 不会立即刷新。您可以使用此方法强制刷新其记录:

/**
 * Force a refresh of media content provider for specific item
 * 
 * @param fileName
 */
private void refreshMediaProvider(Context appContext, String fileName) {
    MediaScannerConnection scanner = null;
    try {
        scanner = new MediaScannerConnection(appContext, null);
        scanner.connect();
        try {
            Thread.sleep(200);
        } catch (Exception e) {
        }
        if (scanner.isConnected()) {
            Log.d(TAG_LOG, "Requesting scan for file " + fileName);
            scanner.scanFile(fileName, null);
        }
    } catch (Exception e) {
        Log.e(TAG_LOG, "Cannot to scan file", e);
    } finally {
        if (scanner != null) {
            scanner.disconnect();
        }
    }
}