[UWP] Bug report: StorageFile.RenameAsync throws an UnauthorizedAccessException with NameCollisionOption.ReplaceExisting

Question

We recently discovered an issue with the StorageFile API while renaming a file created in a picked folder.

Here's the sample code for the issue (just put it in the MainPage's Loaded event):

var picker = new FolderPicker
{
  FileTypeFilter = { "*" }
};

var folder = await picker.PickSingleFolderAsync();
if (folder != null)
{
  await Task.Run(async () =>
  {
    var file = await folder.CreateFileAsync("test.txt", CreationCollisionOption.ReplaceExisting);
    await file.RenameAsync("My File.txt", NameCollisionOption.ReplaceExisting);
  });
}

The issue doesn't occur with the other NameCollisionOptions, or if you remove the call to Task.Run.

The workaround I found is to use the StorageFile.MoveAsync API instead of RenameAsync:

await file.MoveAsync(folder, "My File.txt", NameCollisionOption.ReplaceExisting);

Thanks.

Answer 1

Hello,

Welcome to Microsoft Q&A.

It is a permission design, if you want to continue using RenameAsync, you need to add broadFileSystemAccess capability:

package.txt

After adding the corresponding capability, you need to enable the access permission of the application in

Settings -> Pivacy -> File system

After this, the method can be executed normally, which also confirms that this is a permission design.

It is a bit complicated, you also mentioned that you found a workaround, so you can continue to use it.

---

Update

In addition to using broadFileSystemAccess, there is another method, which is to add folders to FutureAccessList, which is also a way to increase application access permissions. After testing, it works.

if (folder != null)  
{  
    StorageApplicationPermissions.FutureAccessList.Add(folder);  
    var file = await folder.CreateFileAsync("test.txt", CreationCollisionOption.ReplaceExisting);  
    await file.RenameAsync("My File.txt", NameCollisionOption.ReplaceExisting);  
}  

Thanks.