c# - 从任务栏隐藏应用程序

Question

我一直在努力从我的应用程序的任务栏中隐藏另一个应用程序。
我一直在使用 SetWindowLong函数以在 extended style 上设置/删除 WS_EX_APPWINDOW .

我尝试过分别设置和删除属性，以及获取当前的 WindowLong，然后将其删除/添加到那个属性中，如下所示:

SetWindowLong(pMainWindow, GWL_EXSTYLE, GetWindowLong(pMainWindow) & WS_EX_APPWINDOW);

并尝试像这样删除它:

SetWindowLong(pMainWindow, GWL_EXSTYLE, GetWindowLong(pMainWindow) & ~WS_EX_APPWINDOW);

还尝试了这两种方法，但没有先让窗口变长。这是我的全部代码:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    [DllImport("User32.dll")]
    public static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
    [DllImport("User32.dll")]
    public static extern int GetWindowLong(IntPtr hWnd, int nIndex);

    [DllImport("user32.dll")]
    static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);

    private const int SW_HIDE = 0x00;
    private const int SW_SHOW = 0x05;

    private const int WS_EX_APPWINDOW = 0x40000;
    private const int GWL_EXSTYLE = -0x14;

    private void HideWindowFromTaskbar(IntPtr pMainWindow)
    {
        SetWindowLong(pMainWindow, GWL_EXSTYLE, ~WS_EX_APPWINDOW);

        ShowWindow(pMainWindow, SW_HIDE);
        ShowWindow(pMainWindow, SW_SHOW);
    }

    private void ButtonHide_Click(object sender, RoutedEventArgs e)
    {
        HideWindowFromTaskbar(Process.GetProcessesByName("notepad")[0].MainWindowHandle);
    }
}

我注意到 Spy++ 在查看属性时发生了变化。我得到了一堆不同的结果，比如添加了 WS_EX_APPWINDOW，但也随机地让其他属性消失了，等等。
在查看消息时，我还看到它确实收到了类似 STYLE_CHANGED 的消息。

Answer 1

确定哪些窗口在任务栏上有按钮的规则记录在 MSDN 上. Raymond Chen 给出以下 summary这些规则:

There are some basic rules on which windows go into the taskbar. In short:

• If the WS_EX_APPWINDOW extended style is set, then it will show (when visible).
• If the window is a top-level unowned window, then it will show (when visible).
• Otherwise it doesn't show.

您正试图修改另一个应用程序中的窗口这一事实严重妨碍了您。您正在删除 WS_EX_APPWINDOW 扩展样式。这还不够，因为有问题的窗口将是顶级无主窗口(参见要点 2)。一旦创建了窗口，您就无法更改其所有者，并且由于该窗口由另一个进程控制，因此您几乎陷入困境。

剩下的唯一选择是删除 WS_EX_APPWINDOW 扩展样式并将其替换为 WS_EX_TOOLWINDOW。这确实会使窗口离开任务栏，但它会改变 appearance of the window :

The window is intended to be used as a floating toolbar. A tool window has a title bar that is shorter than a normal title bar, and the window title is drawn using a smaller font. A tool window does not appear in the taskbar or in the dialog that appears when the user presses ALT+TAB. If a tool window has a system menu, its icon is not displayed on the title bar. However, you can display the system menu by right-clicking or by typing ALT+SPACE.