在Windows 7 中有些我们经常使用的库（Libraries），例如：音乐库、文档库、视频库、图片库等。还有几十个系统已知文件夹（Known Folders），System、Windows、My Music等。本篇将介绍如何通过Windows API Code Pack 在应用程序中调用这些公共文件夹。

     将Microsoft.WindowsAPICodePack.dll、Microsoft.WindowsAPICodePack.Shell.dll 加入项目中，编写如下XAML 代码，两个<ComboBox> 用来显示Known Folders 和Libraries 选项。

<Grid>
    <Label Content="Know Folders:" Height="30" Width="100" Margin="47,70,356,211" />
    <Label Content="Libraries:" Height="30" Width="100" Margin="48,191,355,90" />
    <ComboBox x:Name="knowFolders" Width="200" Height="25" Margin="186,70,117,211" />
    <ComboBox x:Name="libraries" Width="200" Height="25" Margin="186,190,117,90" />
    <Button x:Name="openKF" Click="openKF_Click" Content="Open Dialog"
            Height="30" Width="90" Margin="296,126,116,155" />
    <Button x:Name="openLB" Click="openLB_Click" Content="Open Dialog"
            Height="30" Width="90" Margin="296,250,117,31" />
</Grid>

在C# 中加入如下命名空间，Shell 用于支持加载公共文件夹，Dialogs用于调用文件夹对话框。

using Microsoft.WindowsAPICodePack.Shell;
using Microsoft.WindowsAPICodePack.Dialogs;

     接下了编写一个ComboBox 加载方法填充上面提到的两个<ComboBox> 内容，通过IKnownFolder 接口获取所有KnownFolders 类中的系统已知文件夹。

private void LoadCombox()
{
    knowFolders.Items.Clear();
    foreach (IKnownFolder kf in KnownFolders.All)
    {
        if (kf != null && kf.CanonicalName != null)
        {
            knowFolders.Items.Add(kf.CanonicalName);
        }
    }
    
    if (knowFolders.Items.Count > 0)
    {
        SortDescription kfSort = new SortDescription();
        knowFolders.Items.SortDescriptions.Add(kfSort);
        knowFolders.SelectedIndex = 0;
    }

    libraries.Items.Clear();
    libraries.Items.Add("Documents");
    libraries.Items.Add("Music");
    libraries.Items.Add("Pictures");
    libraries.Items.Add("Videos");
    libraries.SelectedIndex = 0;
}

     Known Foloder “Open Dialog” 按钮Click 事件，通过CommonOpenFileDialog 类创建对话框，将KnowFolder 初始化为ShellContainer。

private void openKF_Click(object sender, RoutedEventArgs e)
{
    CommonOpenFileDialog cfd = new CommonOpenFileDialog();
    string kfString = knowFolders.SelectedItem as string;
    IKnownFolder kf = KnownFolderHelper.FromCanonicalName(kfString);
    cfd.InitialDirectoryShellContainer = kf as ShellContainer;
    cfd.ShowDialog();
}

Libraries “Open Dialog” 按钮Click 事件：

private void openLB_Click(object sender, RoutedEventArgs e)
{
    string selection = libraries.SelectedItem as string;
    ShellContainer selectedFolder = null;
    switch (selection)
    {
        case "Documents":
            selectedFolder = KnownFolders.DocumentsLibrary as ShellContainer;
            break;
        case "Music":
            selectedFolder = KnownFolders.MusicLibrary as ShellContainer;
            break;
        case "Pictures":
            selectedFolder = KnownFolders.PicturesLibrary as ShellContainer;
            break;
        case "Videos":
            selectedFolder = KnownFolders.VideosLibrary as ShellContainer;
            break;
    }

    CommonOpenFileDialog cfd = new CommonOpenFileDialog();
    cfd.EnsureReadOnly = true;
    cfd.InitialDirectoryShellContainer = selectedFolder;
    cfd.ShowDialog();
}

编译测试：

源代码

CommonFileDialog.zip

本文转自Gnie博客园博客，原文链接：http://www.cnblogs.com/gnielee/archive/2011/03/28/windows7-common-file-dialog.html，如需转载请自行联系原作者