<metro>读取目录名

       首先，我们设计好一个Blank App程序，在添加Button和BlockText控件，在Button中找出Click事件，再单击进入事件。其中xaml中代码显示为：

 <Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
        <Button x:Name="Folder" Content="Button" HorizontalAlignment="Left" Height="52" Margin="260,124,0,0" VerticalAlignment="Top" Width="183" Click="Folder_Click"/>
        <TextBlock x:Name="Foutput" HorizontalAlignment="Left" Height="136" Margin="260,225,0,0" TextWrapping="Wrap" Text="TextBlock" VerticalAlignment="Top" Width="444"/>

    </Grid>

      其次，用FolderPicker类new一个实例folderPicker ，在调用属性 SuggestedStartLocation设定起始位置。接着用FileTypeFilter.Add增加可以识别的文件类型。再用StorageFolder类新建一个实例，等待异步PickSingleFolderAsync方法， 获得一个目录。 通过StorageApplicationPermissions.FutureAccessList.AddOrReplace方法，得到选择的目录权限。最后，将它的目录名显示到BlockText中。按F5演示成功。其中事件中代码如下：

      private async void Folder_Click(object sender, RoutedEventArgs e)
        {
            FolderPicker folderPicker = new FolderPicker();
            folderPicker.SuggestedStartLocation = PickerLocationId.Desktop;
            folderPicker.FileTypeFilter.Add(".docx");
            folderPicker.FileTypeFilter.Add(".xlsx");
            folderPicker.FileTypeFilter.Add(".pptx");

            StorageFolder folder = await folderPicker.PickSingleFolderAsync();
            if (folderPicker != null)
            {
                StorageApplicationPermissions.FutureAccessList.AddOrReplace("PickedFolderToken", folder);
                Foutput.Text = "Picked folder: " + folder.Name;
            }
            else
            {
                Foutput.Text = "Operation cancelled.";
            }

        }