使用`ACTION_OPEN_DOCUMENT_TREE`访问文件

<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>
<application
    ...
    android:requestLegacyExternalStorage="true">
    ...
</application>

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
    if (!Environment.isExternalStorageManager()) {
        Intent intent = new Intent(Settings.ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION);
        intent.setData(Uri.parse("package:" + getPackageName()));
        startActivityForResult(intent, REQUEST_CODE);
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == REQUEST_CODE && resultCode == RESULT_OK) {
        Uri treeUri = data.getData();
        if (treeUri != null) {
            // 保存 Uri 并请求权限
            int flags = Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION;
            getContentResolver().takePersistableUriPermission(treeUri, flags);
        }
    }
}