4.4.2 ContentProvider再探——Document Provider

[] projection, String sortOrder) throws FileNotFoundException { final MatrixCursor result = new MatrixCursor(resolveDocumentProjection(projection)); final File parent = getFileForDocId(parentDocumentId); for (File file : parent.listFiles()) { // Adds the file's display name, MIME type, size, and so on. includeFile(result, null, file); } return result;}Implement queryDocument@Overridepublic Cursor queryDocument(String documentId, String[] projection) throws FileNotFoundException { // Create a cursor with the requested projection, or the default projection. final MatrixCursor result = new MatrixCursor(resolveDocumentProjection(projection)); includeFile(result, documentId, null); return result;}好吧，文档中的内容大概就是这些了：一开始是想自己翻译的，后来在泡在网上的日子上找到了这一篇文档的中文翻译，就偷下懒了~中文翻译链接：android存储访问框架Storage Access Framework3.Android 4.4 获取资源路径问题：其实这个SAF我们用得较多的地方无非是获取图片的Uri而已，而从上面的例子我们也发现了：我们这样获取的链接是这样的：content://com.android.providers.media.documents/document/image%3A69983这样的链接，我们直接通过上面的方法获得uri即可！当然，这个是4.4 或者以上版本的~！如果是以前的版本：uri可能是这样的：content://media/external/images/media/image%3A69983这里贴下在别的地方看到的一个全面的方案，原文链接：Android4.4中获取资源路径问题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]; } // TODO handle non-primary volumes } // 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 getDataColumn(context, uri, null, null); } // File else if ("file".equalsIgnoreCase(uri.getScheme())) { return uri.getPath(); } return null;}/** * Get the value of the data column for this Uri. This is useful for * MediaStore Uris, and other file-based ContentProviders. * * @param context The context. * @param uri The Uri to query. * @param selection (Optional) Filter used in the query. * @param selectionArgs (Optional) Selection arguments used in the query. * @return The value of the _data column, which is typically a file path. */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 column_index = cursor.getColumnIndexOrThrow(column); return cursor.getString(column_index); } } finally { if (cursor != null) cursor.close(); } return null;}/** * @param uri The Uri to check. * @return Whether the Uri authority is ExternalStorageProvider. */public static boolean isExternalStorageDocument(Uri uri) { return "com.android.externalstorage.documents".equals(uri.getAuthority());}/** * @param uri The Uri to check. * @return Whether the Uri authority is Dow