GetFolderFromPathAsync failed.

Question

Hi All, i use a folderpicker to get a StorageFolder and send the StorageFolder->path to the dll, this dll is used both in desktop & metro app, so i want use the path as input parameter, the sample codes like this:

create_task(folderPicker->PickSingleFolderAsync()).then([this](StorageFolder^ folder)
{
 String^ folder_path = folder->Path;
 create_task(StorageFolder::GetFolderFromPathAsync(folder_path)).then([this](StorageFolder ^ folder2)
 {
  if (folder2)
  {
   OutputTextBlock->Text = "open file: " + folder2->Name + "\n";
  }
 });
});

is there any other way to solve this issue? thanks!

Answer 1

Hi,

You should use nested .then() in order to catch the correct exception.

auto pickFolderTask = create_task((folderPicker->PickSingleFolderAsync()).then([this](StorageFolder^ folder)
{
 String^ folder_path = folder->Path;

return StorageFolder::GetFolderFromPathAsync(folder_path);

}).then([this](StorageFolder ^ folder2)

{

 if (folder2)
  {
   OutputTextBlock->Text = "open file: " + folder2->Name + "\n";
  }
 });

});

This should help you with diagnosis of the error.

-Sagar

Answer 2

The GetFolderFromPathAsync API may be failing due to the permissions for the path you are passing to it (the directory selected from the FolderPicker). Note the StorageFolder->Path may not always be populated. See the Remarks section for the StorageFolder->Path documentation.

---

David Lamb

Answer 3

the app will popup a exception dialog, error message is "An invalid parameter was passed to a function that considers invalid parameters fatal."  it may be caused by permission of metro file system. so I have to try using the StorageFolder^ as the input parameter of the dll. thanks Sagar B.Joshi & DavlidLamb.