C# 显示隐藏窗口

Question

我正在开发一个 Excel 插件。在某些时候，我可以接收异步事件。如果 Excel 窗口在这些事件上隐藏，我需要能够显示该窗口。

我能够存储 Hwnd 属性，我相信它必须是一个不可变的 int/引用来标识我的 Excel 窗口。

有人可以详细说明这个 Hwnd 吗？并解释如何使用它显示 C# 中的隐藏窗口？

提前感谢大家；）

更新：很快，这就是解决我的问题的代码：

    /// <summary>Enumeration of the different ways of showing a window using
    /// ShowWindow</summary>
    private enum WindowShowStyle : uint
    {
        /// <summary>Hides the window and activates another window.</summary>
        /// <remarks>See SW_HIDE</remarks>
        Hide = 0,
        /// <summary>Activates and displays a window. If the window is minimized
        /// or maximized, the system restores it to its original size and
        /// position. An application should specify this flag when displaying
        /// the window for the first time.</summary>
        /// <remarks>See SW_SHOWNORMAL</remarks>
        ShowNormal = 1,
        /// <summary>Activates the window and displays it as a minimized window.</summary>
        /// <remarks>See SW_SHOWMINIMIZED</remarks>
        ShowMinimized = 2,
        /// <summary>Activates the window and displays it as a maximized window.</summary>
        /// <remarks>See SW_SHOWMAXIMIZED</remarks>
        ShowMaximized = 3,
        /// <summary>Maximizes the specified window.</summary>
        /// <remarks>See SW_MAXIMIZE</remarks>
        Maximize = 3,
        /// <summary>Displays a window in its most recent size and position.
        /// This value is similar to "ShowNormal", except the window is not
        /// actived.</summary>
        /// <remarks>See SW_SHOWNOACTIVATE</remarks>
        ShowNormalNoActivate = 4,
        /// <summary>Activates the window and displays it in its current size
        /// and position.</summary>
        /// <remarks>See SW_SHOW</remarks>
        Show = 5,
        /// <summary>Minimizes the specified window and activates the next
        /// top-level window in the Z order.</summary>
        /// <remarks>See SW_MINIMIZE</remarks>
        Minimize = 6,
        /// <summary>Displays the window as a minimized window. This value is
        /// similar to "ShowMinimized", except the window is not activated.</summary>
        /// <remarks>See SW_SHOWMINNOACTIVE</remarks>
        ShowMinNoActivate = 7,
        /// <summary>Displays the window in its current size and position. This
        /// value is similar to "Show", except the window is not activated.</summary>
        /// <remarks>See SW_SHOWNA</remarks>
        ShowNoActivate = 8,
        /// <summary>Activates and displays the window. If the window is
        /// minimized or maximized, the system restores it to its original size
        /// and position. An application should specify this flag when restoring
        /// a minimized window.</summary>
        /// <remarks>See SW_RESTORE</remarks>
        Restore = 9,
        /// <summary>Sets the show state based on the SW_ value specified in the
        /// STARTUPINFO structure passed to the CreateProcess function by the
        /// program that started the application.</summary>
        /// <remarks>See SW_SHOWDEFAULT</remarks>
        ShowDefault = 10,
        /// <summary>Windows 2000/XP: Minimizes a window, even if the thread
        /// that owns the window is hung. This flag should only be used when
        /// minimizing windows from a different thread.</summary>
        /// <remarks>See SW_FORCEMINIMIZE</remarks>
        ForceMinimized = 11
    }

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

    static void ContentClick(object obj, EventArgs ea)
    {
        Microsoft.Office.Interop.Excel.Application oExcelApp = (Microsoft.Office.Interop.Excel.Application)System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application");
        oExcelApp.Visible = true;
        ShowWindow( (System.IntPtr) Globals.ThisWorkbook.Application.Hwnd, WindowShowStyle.ShowMaximized);
    }

Answer 1

hWnd 表示窗口句柄。它是窗口实例的标识句柄。

至于显示它，您可以使用 user32.ShowWindow API。这是 P/Invoke 签名，由 pinvoke.net 提供：

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

这是 <代码>ShowWindowCommands 枚举：

/// <summary>Enumeration of the different ways of showing a window using
/// ShowWindow</summary>
private enum WindowShowStyle : uint
{
    /// <summary>Hides the window and activates another window.</summary>
    /// <remarks>See SW_HIDE</remarks>
    Hide = 0,
    /// <summary>Activates and displays a window. If the window is minimized
    /// or maximized, the system restores it to its original size and
    /// position. An application should specify this flag when displaying
    /// the window for the first time.</summary>
    /// <remarks>See SW_SHOWNORMAL</remarks>
    ShowNormal = 1,
    /// <summary>Activates the window and displays it as a minimized window.</summary>
    /// <remarks>See SW_SHOWMINIMIZED</remarks>
    ShowMinimized = 2,
    /// <summary>Activates the window and displays it as a maximized window.</summary>
    /// <remarks>See SW_SHOWMAXIMIZED</remarks>
    ShowMaximized = 3,
    /// <summary>Maximizes the specified window.</summary>
    /// <remarks>See SW_MAXIMIZE</remarks>
    Maximize = 3,
    /// <summary>Displays a window in its most recent size and position.
    /// This value is similar to "ShowNormal", except the window is not
    /// actived.</summary>
    /// <remarks>See SW_SHOWNOACTIVATE</remarks>
    ShowNormalNoActivate = 4,
    /// <summary>Activates the window and displays it in its current size
    /// and position.</summary>
    /// <remarks>See SW_SHOW</remarks>
    Show = 5,
    /// <summary>Minimizes the specified window and activates the next
    /// top-level window in the Z order.</summary>
    /// <remarks>See SW_MINIMIZE</remarks>
    Minimize = 6,
      /// <summary>Displays the window as a minimized window. This value is
      /// similar to "ShowMinimized", except the window is not activated.</summary>
    /// <remarks>See SW_SHOWMINNOACTIVE</remarks>
    ShowMinNoActivate = 7,
    /// <summary>Displays the window in its current size and position. This
    /// value is similar to "Show", except the window is not activated.</summary>
    /// <remarks>See SW_SHOWNA</remarks>
    ShowNoActivate = 8,
    /// <summary>Activates and displays the window. If the window is
    /// minimized or maximized, the system restores it to its original size
    /// and position. An application should specify this flag when restoring
    /// a minimized window.</summary>
    /// <remarks>See SW_RESTORE</remarks>
    Restore = 9,
    /// <summary>Sets the show state based on the SW_ value specified in the
    /// STARTUPINFO structure passed to the CreateProcess function by the
    /// program that started the application.</summary>
    /// <remarks>See SW_SHOWDEFAULT</remarks>
    ShowDefault = 10,
    /// <summary>Windows 2000/XP: Minimizes a window, even if the thread
    /// that owns the window is hung. This flag should only be used when
    /// minimizing windows from a different thread.</summary>
    /// <remarks>See SW_FORCEMINIMIZE</remarks>
    ForceMinimized = 11
}

Answer 2

HWnd 是一个 Windows 句柄，在 C# 中它实际上是一个 IntPtr 类型。
尝试创建一个基于 IWin32Window 的包装类，并在调用 Show() 时使用它，例如

public class WndWrapper : IWin32Window
{
    IntPtr m_Handle;
    public WndWrapper(long pHandle)
    {
        m_Handle = (IntPtr)pHandle;
    }

    #region IWin32Window Members

    public IntPtr Handle
    {
        get { return m_Handle; }
    }

    #endregion
}

然后像这样调用它：

WndWrapper oWnd = new WndWrapper(pHandle);
MyForm oDlg = new MyForm();
oDlg.Show(oWnd);

请小心，因为 HWND 元素是非托管的，您将负责以确保它们在需要时得到处置。