正确的方法（在.NET）将焦点切换到另一个应用程序 [英] Correct way (in .NET) to switch the focus to another application

问题描述

这是我到目前为止有：

    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。

It has two problems.

1. 有人告诉我，SwitchToThisWindow是depricated。
2. 如果应用程序B被最小化，该函数默默地失效从用户的角度来看。

那么，什么是正确的方式做到这一点？

So what's the right way to do this?

推荐答案

获取窗口句柄（HWND），然后用这个user32.dll中的功能：

Get the window handle (hwnd), and then use this user32.dll function:

VB.net声明：

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

C＃声明：

C# declaration:

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

我的VB.net是很生疏，这里是C＃code，但：

My VB.net is VERY rusty, here is the C# code though:

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

[System.Runtime.InteropServices.DllImport("user32.dll")]
public static extern int SetForegroundWindow(IntPtr hwnd);
public void BringWindowToFront()
{
    string processName = "name";
    string processFilePath = @"C:\Program Files\B\B.exe";
    //get the process
    Process bProcess = Process.GetProcessesByName(processName).FirstOrDefault();
    //check if the process is nothing or not.
    if (bProcess != null)
    {
        //get the  hWnd of the process
        IntPtr hwnd = bProcess.MainWindowHandle;
        if (hwnd == 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((int)bProcess.MainWindowHandle);
    }
    else
    {
        //tthe process is nothing, so start it
        Process.Start(processName);
    }
}

使用code，这将非常简单，如设置适当的工艺参数，并呼吁 BringWindowToFront（）;

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