private void requestStoragePermission if ActivityCompatshouldShowRequestPermissionRationalethis ManifestpermissionWRITE_EXTERNAL_STORAGE new AlertDialogBuilderthis

private void requestStoragePermission() { if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) { new MaterialAlertDialogBuilder(this) .setTitle("权限申请") .setMessage("该软件需要使用存储权限来存放下载文件") .setPositiveButton("同意", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, PERMISSION_REQUEST_CODE); } }) .setNegativeButton("拒绝", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }) .show(); } else { ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, PERMISSION_REQUEST_CODE); } }