.net - 将焦点切换到另一个应用程序的正确方法(在 .NET 中)

Question

这是我到目前为止:

Dim bProcess = Process.GetProcessesByName("By").FirstOrDefault
If bProcess IsNot Nothing Then
    SwitchToThisWindow(bProcess.MainWindowHandle, True)
Else
    Process.Start("C:\Program Files\B\B.exe")
End If

它有两个问题。

有人告诉我，不推荐使用 SwitchToThisWindow。

如果应用程序 B 被最小化，从用户的角度来看，这个函数会默默地失败。

那么这样做的正确方法是什么？

Answer 1

获取窗口句柄(hwnd)，然后使用这个 user32.dll 函数:

VB.net声明:

Declare Function SetForegroundWindow Lib "user32.dll" (ByVal hwnd As Integer) As Integer 

C#声明:

[DllImport("user32.dll")] public static extern int SetForegroundWindow(int hwnd) 

一个考虑是如果窗口被最小化，这将不起作用，所以我编写了以下方法来处理这种情况。这是 C# 代码，将其迁移到 VB 应该相当简单。

[System.Runtime.InteropServices.DllImport("user32.dll")]
[return: System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.Bool)]
private static extern bool ShowWindow(IntPtr hWnd, ShowWindowEnum flags);

[System.Runtime.InteropServices.DllImport("user32.dll")]
private static extern int SetForegroundWindow(IntPtr hwnd);

private enum ShowWindowEnum
{
    Hide = 0,
    ShowNormal = 1, ShowMinimized = 2, ShowMaximized = 3,
    Maximize = 3, ShowNormalNoActivate = 4, Show = 5,
    Minimize = 6, ShowMinNoActivate = 7, ShowNoActivate = 8,
    Restore = 9, ShowDefault = 10, ForceMinimized = 11
};

public void BringMainWindowToFront(string processName)
{
    // get the process
    Process bProcess = Process.GetProcessesByName(processName).FirstOrDefault();

    // check if the process is running
    if (bProcess != null)
    {
        // check if the window is hidden / minimized
        if (bProcess.MainWindowHandle == IntPtr.Zero)
        {
            // the window is hidden so try to restore it before setting focus.
            ShowWindow(bProcess.Handle, ShowWindowEnum.Restore);
        }

        // set user the focus to the window
        SetForegroundWindow(bProcess.MainWindowHandle);
    }
    else
    {
        // the process is not running, so start it
        Process.Start(processName);
    }
}

使用该代码，就像设置适当的流程变量并调用 BringMainWindowToFront("processName"); 一样简单。