将焦点切换到另一个应用程序的正确方法（在 .NET 中）

Question

这就是我到目前为止所遇到的：

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。

1. 有些人告诉我 SwitchToThisWindow 已被弃用。
2. 如果应用程序 B 最小化，则从用户的角度来看，此功能会默默地失败。

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) 

一个考虑因素是，如果窗口最小化，这将不起作用，因此我编写了以下也处理窗口句柄的方法这个案例。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

Answer 2

还有另一种方法，它使用不为人所知的 UI 自动化 API：

AutomationElement element = AutomationElement.FromHandle(process.MainWindowHandle);
if (element != null)
{
    element.SetFocus();
}

大多数情况下，如果可以切换到该窗口，则这将起作用。 Windows 中有很多限制（安全性、UAC、特定配置等），这些限制可能会阻止您改变最终用户的关注点。

Answer 3

在您的项目中创建一个新类并将以下代码复制粘贴到其中。

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Threading;

namespace MyProject
{
    public class ProcessHelper
    {
        public static void SetFocusToExternalApp(string strProcessName)
        {
            Process[] arrProcesses = Process.GetProcessesByName(strProcessName);
            if (arrProcesses.Length > 0)
            {

                IntPtr ipHwnd = arrProcesses[0].MainWindowHandle;
                Thread.Sleep(100);
                SetForegroundWindow(ipHwnd);

            }
        }

    //API-declaration
    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    public static extern bool SetForegroundWindow(IntPtr hWnd);

    }
}

现在将以下代码复制粘贴到您所需的区域。

string procName = Process.GetCurrentProcess().ProcessName;
ProcessHelper.SetFocusToExternalApp(procName);

在这里，您调用该函数将焦点转移到其他应用程序的窗口。

Answer 4

在 VB.Net 中，您可以使用 AppActivate< /a> 函数。

Dim App As Process() = Process.GetProcessesByName("program.exe")
If App.Length > 0 Then
   AppActivate(App(0).Id)
End If

Answer 5

我使用 SetForegroundWindow 来显示另一个应用程序的窗口。

[DllImport("user32.dll")]
static extern bool SetForegroundWindow(IntPtr hWnd);

如何给予另一个进程焦点来自 C#？

Answer 6

这对我来说工作

[DllImport("user32.dll", SetLastError = true)]
static extern void SwitchToThisWindow(IntPtr hWnd, bool turnOn);
[STAThread]
        static void Main()
        {
            Process bProcess = Process.GetProcessesByName(processnamehere).FirstOrDefault() ;
            if (bProcess != null)
                    {
                        SwitchToThisWindow(bProcess.MainWindowHandle, true);
                    }
                GC.Collect();
        }   

Answer 7

导入：

Imports System.Runtime.InteropServices

将其放入模块中

<DllImport("user32.dll")> _
Private Function SetForegroundWindow(hWnd As IntPtr) As Boolean
End Function

Public Sub FocusWindow(ByVal ProcessName As String)
    Dim p As System.Diagnostics.Process = System.Diagnostics.Process.GetProcessesByName(ProcessName).FirstOrDefault
    If p IsNot Nothing Then
        SetForegroundWindow(p.MainWindowHandle)
        SendKeys.SendWait("~") ' maximize the application if it's minimized
    End If
End Sub

用法：

FocusWindow("Notepad")

来源： http://www.codeproject.com/Tips/232649/Setting-Focus-on-an-External-application#_ rating

Answer 8

当我尝试使用从以下代码获取的 exe 以管理员身份运行 SQL Server Management Studio 和 Visual Studio 等应用程序时，以下内容对我有用。

切换帮助

public class ToggleHelper
{
    [System.Runtime.InteropServices.DllImport("user32.dll")]
    [return: System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.Bool)]
    private static extern bool ShowWindow(IntPtr hWnd, EnumForWindow enumVal);

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

    private enum EnumForWindow
    {
        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 SetForeGroundMainWindowHandle(string processName)
    {

        Console.WriteLine("SetForeGroundMainWindowHandle Called - for "+ processName);
        Process p = Process.GetProcessesByName(processName).FirstOrDefault();

        if (p != null)
        {
            Console.WriteLine(p.MainWindowHandle.ToString());
            ShowWindow(p.MainWindowHandle, EnumForWindow.Restore);
            System.Threading.Thread.Sleep(5000);
            ShowWindow(p.MainWindowHandle, EnumForWindow.ShowMaximized);
            //System.Threading.Thread.Sleep(5000);
            SetForegroundWindow(p.MainWindowHandle);
        }
        else
        {
            Process.Start(processName);
        }
    }
}

客户端

class Program
{
    static void Main(string[] args)
    {
        //RUN AS Administrator
        var y = Process.GetProcesses().Where(pr => pr.MainWindowHandle != IntPtr.Zero);
        foreach (Process proc in y)
        {
            Console.WriteLine(proc.ProcessName);
        }

        ToggleHelper t = new ToggleHelper();

        int a = 0;
        while (a <= 1)
        {
            t.SetForeGroundMainWindowHandle("Ssms");
            System.Threading.Thread.Sleep(30000);
            t.SetForeGroundMainWindowHandle("devenv");
            System.Threading.Thread.Sleep(18000);
        }
        Console.ReadLine();
    }
}