UWP - Windows IOT - 从 USB 驱动器中名为 "ad_runner" 的特定文件夹获取文件

Question

当我尝试访问位于 USB 驱动器的名为 "ad_runner" 的文件夹中的文件时，出现未处理的错误。我做错了什么？

        async void AccessTheWebAsync()
    {
        StorageFolder remd = await KnownFolders.RemovableDevices.GetFolderAsync("ad_runner");
        IReadOnlyList<StorageFile> fileList = await remd.GetFilesAsync();
        foreach (StorageFile file in fileList)
        {
            dir_lbl.Text = dir_lbl.Text + "\r\n" + file.Name;
        }
    }

Answer 1

如果您尝试调用 await KnownFolders.RemovableDevices.GetFoldersAsync();，您会发现第一次调用不是 return 可移动设备中的文件夹，而是可移动设备本身。所以，我稍微修改了你的代码，首先检索所有连接的可移动设备，然后检查名为 "ad_runner" 的内部文件夹：

async void AccessTheWebAsync()
    {
        //Maybe you want to do this inside a try catch and verify that at least 1 device is connected before you go on....
        var folderList = await KnownFolders.RemovableDevices.GetFoldersAsync();

        foreach (var device in await KnownFolders.RemovableDevices.GetFoldersAsync())
        {
            try
            {
                StorageFolder remd = await device.GetFolderAsync("ad_runner");
                IReadOnlyList<StorageFile> fileList = await remd.GetFilesAsync();
                foreach (StorageFile file in fileList)
                {
                    //Your logic here....
                   dir_lbl.Text = dir_lbl.Text + "\r\n" + file.Name;
                }
            }
            catch (Exception)
            {

            }
            await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
            {
                rightGridWrapper.Children.Add(new TextBlock { Text = $"DeviceName: {device.Name}" });
            });
        }
}