关键词 ：安卓,权限,ExternalStorage,SDCard
Android R上分区存储的限制得到进一步加强，无论APP的
targetsdkversion
是多少，都将无法访问
Android/data
和
Android/obb
这二个应用私有目录。这无疑对会部分APP的业务场景及用户体验造成冲击，典型的如下：
- 文件管理类软件：微信、QQ传输的文件无法展示给用户以便捷使用
- 垃圾清理类软件：清理缓存功能受阻
声明
MANAGE_EXTERNAL_STORAGE
权限可以使用
File
遍历除
Android/data
和
Android/obb
之外的目录。如需确定您的应用是否已获得
MANAGE_EXTERNAL_STORAGE
权限，请调用
Environment.isExternalStorageManager()
。
android - Delete Audio From Sdcard - Stack Overflow ：
@Override
public void onActivityResult(int requestCode,int resultCode,Intent resultData) {
if (resultCode != RESULT_OK)
return;
Uri treeUri = resultData.getData();
DocumentFile pickedDir = DocumentFile.fromTreeUri(this, treeUri);
grantUriPermission(getPackageName(), treeUri, Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
getContentResolver().takePersistableUriPermission(treeUri, Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
DocumentFile YourAudioFile= pickedDir.findFile("YourAudioFileNameGoesHere");
// And here you can delete YourAudioFile or do whatever you want with it
Uri
Uri的构造： “content://com.android.externalstorage.documents/tree/primary%3AAndroid%2Fdata/document/primary%3AAndroid%2Fdata”;
外部存储：content://com.android.externalstorage.documents 选择的目录树关键字：/tree/primary 选择的文件关键字：/document/primary
Uri uri = Uri.parse(“content://com.android.externalstorage.documents/tree/primary%3AAndroid%2Fdata/document/primary%3AAndroid%2Fdata”);
DocumentFile
| [DocumentFile | Android Developers](https://developer.android.com/reference/androidx/documentfile/provider/DocumentFile) |
// 包名/file目录
public static final String NOTE_BOOK_FILES_URI =
"content://com.android.externalstorage.documents/tree/primary%3AAndroid%2Fdata/document/primary%3AAndroid%2Fdata%2Fcom.freeme.freemenote%2Ffiles";
//判断文件是否存在 DocumentFile
Uri filesUri = Uri.parse(NOTE_BOOK_FILES_URI);
boolean isExistsFilesDir = DocumentFile.fromSingleUri(mContext, filesUri).exists();
//不存在则创建 packageUri为父目录树
if (!isExistsFilesDir) {
try {
filesUri = DocumentsContract.createDocument(mContext.getContentResolver(), packageUri, "vnd.android.document/directory", "files");
} catch (FileNotFoundException e) {
e.printStackTrace();
//复制文件 File to DocumentFile DocumentsContract
public static void fileToDocumentFile(Context context, File originFile, String fileName, Uri parentUri) {
//String fileName = originFile.getName();
try {
InputStream in = new FileInputStream(originFile);
Uri documentFile = DocumentsContract.createDocument(context.getContentResolver(), parentUri, "*/*", fileName);
//DocumentFile写入流
OutputStream out = context.getContentResolver().openOutputStream(documentFile);
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
in.close();
out.close();
} catch (Exception e) {
e.printStackTrace();
// 读取DocumentFile to File
public static List<File> documentFileToFile(Context context) {
List<File> allFile = new ArrayList<File>();
Uri dirUri = Uri.parse(Constant.NOTE_BOOK_FILES_URI);
DocumentFile documentFile = DocumentFile.fromTreeUri(context, dirUri);
//遍历DocumentFile
DocumentFile[] files = documentFile.listFiles();
LogUtil.d(Constant.TAG, "documentFileToFile files count=" + files.length);
for (DocumentFile file : files) {
String fileName = file.getName();
Uri fileUri = file.getUri();
LogUtil.d(Constant.TAG, "documentFileToFile fileName=" + fileName + " fileUri=" + fileUri);
try {
//DocumentFile输入流
InputStream in = context.getContentResolver().openInputStream(fileUri);
File newFile = new File(Constant.BACKUP_DIR_PATH, fileName);
OutputStream out = new FileOutputStream(newFile);
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
in.close();
out.close();
allFile.add(newFile);
} catch (Exception e) {