从 Powershell 调用 user32.dll 中的 keybd_event

Question

我正试图阻止屏幕保护程序启动。 我试过发送击键，但它们都需要按标题抓取一个窗口。 如果桌面上没有打开的窗口，则没有什么可以抓取的。

所以我找到了一些可行的方法，但我不是 C# 向导。 它基于Simulating a keypress AND keyrelease in another application?

下面的代码应该发送 1，但我遗漏了一些东西。在我从 Powershell 调用新类型之前，我没有收到任何错误。 在这个工作之后，我想让它发送一个 F15 来重置屏幕保护程序倒计时但不修改屏幕上的东西。 （但我要先爬，先发送 1s）

Add-Type @"
using System.Runtime.InteropServices;

namespace ConsoleApplication1 
{
    public static class PressKeyForMe 
    { 
        [DllImport("user32.dll")] 
        static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, UIntPtr dwExtraInfo);

        //public static void Main(string[] args)
        public static void Main()
        {            
            //This code will press and hold the '1' button for 3 secs, and then will release for 1 second
            //VK_F15 0x7E
            keybd_event((byte)0x31, (byte)0x02, 0, UIntPtr.Zero);
            Thread.Sleep(3000);

            keybd_event((byte)0x31, (byte)0x82, (uint)0x2, UIntPtr.Zero);
            Thread.Sleep(1000);
        }
    }

}
"@
cls

#all of these give me: Unable to find type
[void] [PressKeyForMe]::Main()
[void] [ConsoleApplication1]::PressKeyForMe()
[void] [PressKeyForMe.Main]
[void] [ConsoleApplication1.Main]
[void] [ConsoleApplication1.PressKeyForMe]::Main()

Answer 1

您似乎在该类型定义中缺少一些using-statements：

Add-Type @"
using System;
using System.Threading;
using System.Runtime.InteropServices;

namespace ConsoleApplication1 
{
    public static class PressKeyForMe 
    { 
        [DllImport("user32.dll")] 
        static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, UIntPtr dwExtraInfo);

        //public static void Main(string[] args)
        public static void Main()
        {            
            //This code will press and hold the '1' button for 3 secs, and then will release for 1 second
            //VK_F15 0x7E
            keybd_event((byte)0x31, (byte)0x02, 0, UIntPtr.Zero);
            Thread.Sleep(3000);

            keybd_event((byte)0x31, (byte)0x82, (uint)0x2, UIntPtr.Zero);
            Thread.Sleep(1000);
        }
    }

}
"@

现在应该可以工作了：

[ConsoleApplication1.PressKeyForMe]::Main()

---

您也可以只添加方法并将自动生成的类型分配给变量：

$KeyPresser = Add-Type -MemberDefinition @"
[DllImport("user32.dll")]
static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, UIntPtr dwExtraInfo);

public static void PressOne(int press, int release)
{
    //This code will press and hold the '1' button for 3 secs, and then will release for 1 second
    //VK_F15 0x7E
    keybd_event((byte)0x31, (byte)0x02, 0, UIntPtr.Zero);
    Thread.Sleep(press);

    keybd_event((byte)0x31, (byte)0x82, (uint)0x2, UIntPtr.Zero);
    Thread.Sleep(release);
}

public static void PressOne()
{
    PressOne(3000, 1000);
}
"@ -Name PressKeyForMe -UsingNamespace System.Threading -PassThru

现在您可以在没有完整类型名称的情况下调用该方法：

PS C:\> $KeyPresser::PressOne() 
PS C:\> $KeyPresser::PressOne(400,120) # you really need to press 3 seconds?

Answer 2

感谢 Mathias 修复了我上面的代码。我能够完成我的脚本！

出于好奇，下面是我如何让 F15 键工作的方法。 只需每隔几分钟使用[ScreenSpender.PressKeyForMe]::Main() 即可保持屏幕保护程序处于关闭状态。 感谢 John Savard 在键盘扫描代码方面提供的帮助。

#The following is an attempt to prevent the SceenSaver from kicking-in during installation
#We call it using this
#[ScreenSpender.PressKeyForMe]::Main()

Add-Type @"
using System;
using System.Threading;
using System.Runtime.InteropServices;

namespace ScreenSpender 
{
    public static class PressKeyForMe 
    { 
        [DllImport("user32.dll")] 
        static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, UIntPtr dwExtraInfo);

        //public static void Main(string[] args)
        public static void Main()
        {
            //bScan = PS/2 scan code. (We happen to be using Set 1)
            // Make  = when you press the key
            // Break = when you release the key
            //VK_F15 0x7E
            //SC_F15 0x5D   (Scan code set 1) (or 0x64) (http://www.quadibloc.com/comp/scan.htm  - by John Savard)
            //private const int KEYEVENTF_KEYUP = 0x02;
            //This code will press and hold the 'F15' key for 250 Milliseconds, and then will release for 200 Milliseconds
            keybd_event((byte)0x7E, (byte)0x5D, 0, UIntPtr.Zero);
            Thread.Sleep(250);

            // Release for 200 Milliseconds
            keybd_event((byte)0x7E, (byte)0x5D, (uint)0x2, UIntPtr.Zero);
            Thread.Sleep(200);
        }
    }
}
"@