.Net 4 JumpTask禁用“从此列表中删除”

我在.NET 4中使用了跳转列表,到目前为止我还可以正常工作,但是我不能将跳转任务设为只读,这样用户就不能从跳转列表中删除该任务。我要删除要列出的Pin并从此列表选项中删除。我不知道怎么做。这是我的代码:

var jumpList = new JumpList();

var jumpTask = new JumpTask
    {
        ApplicationPath = Path.Combine(Utilities.AppDir, @"SevenUpdate.exe"),
        IconResourcePath = Path.Combine(Utilities.AppDir, @"SevenUpdate.Base.dll"),
        IconResourceIndex = 2,
        Title = SevenUpdate.Properties.Resources.CheckForUpdates,
        CustomCategory = SevenUpdate.Properties.Resources.Tasks,
        Arguments = "-check",
    };

jumpList.JumpItems.Add(jumpTask);

jumpTask = new JumpTask
    {
        ApplicationPath = Path.Combine(Utilities.AppDir, @"SevenUpdate.exe"),
        IconResourcePath = Path.Combine(Utilities.AppDir, @"SevenUpdate.Base.dll"),
        IconResourceIndex = 5,
        Title = SevenUpdate.Properties.Resources.RestoreHiddenUpdates,
        CustomCategory = SevenUpdate.Properties.Resources.Tasks,
        Arguments = "-hidden"
    };

jumpList.JumpItems.Add(jumpTask);

jumpTask = new JumpTask
    {
        ApplicationPath = Path.Combine(Utilities.AppDir, @"SevenUpdate.exe"),
        IconResourcePath = Path.Combine(Utilities.AppDir, @"SevenUpdate.Base.dll"),
        IconResourceIndex = 4,
        Title = SevenUpdate.Properties.Resources.ViewUpdateHistory,
        CustomCategory = SevenUpdate.Properties.Resources.Tasks,
        Arguments = "-history",
    };

jumpList.JumpItems.Add(jumpTask);

jumpTask = new JumpTask
    {
        ApplicationPath = Path.Combine(Utilities.AppDir, @"SevenUpdate.exe"),
        IconResourcePath = Path.Combine(Utilities.AppDir, @"SevenUpdate.Base.dll"),
        IconResourceIndex = 3,
        Title = SevenUpdate.Properties.Resources.ChangeSettings,
        CustomCategory = SevenUpdate.Properties.Resources.Tasks,
        Arguments = "-settings",
    };

jumpList.JumpItems.Add(jumpTask);

JumpList.SetJumpList(Current, jumpList);