How to bring focus to window by process name?

Question

If I\'m understanding this correctly this code should capture the active window and keep it in focus. concentr.exe is the process name. How do I bring a window in focus base

Answer 1

I found it:

Param(
    [string] $proc="C:\Program Files (x86)\Citrix\ICA Client\concentr.exe",
    [string] $adm
)
Clear-Host

Add-Type @"
    using System;
    using System.Runtime.InteropServices;
    public class WinAp {
      [DllImport("user32.dll")]
      [return: MarshalAs(UnmanagedType.Bool)]
      public static extern bool SetForegroundWindow(IntPtr hWnd);

      [DllImport("user32.dll")]
      [return: MarshalAs(UnmanagedType.Bool)]
      public static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
    }
"@
$p = Get-Process | Where {$_.mainWindowTitle} |
    Where {$_.Name -like "$proc"}
if (($p -eq $null) -and ($adm -ne "")) {
    Start-Process "$proc" -Verb runAs
} elseif (($p -eq $null) -and ($adm -eq "")) {
    Start-Process "$proc"
} else {
    $h = $p.MainWindowHandle
    [void] [WinAp]::SetForegroundWindow($h)
    [void] [WinAp]::ShowWindow($h, 3)
}

Answer 2

Have you thought of using the Window Name? I've found this bit of code to work great and not take up a lot of space:

$wshell = New-Object -ComObject wscript.shell
$wshell.AppActivate('New Tab - Google Chrome')

Also, if you need to just Alt-TAB back to the last thing that ran (ie: you need focus to come back to the script window after firing something off) try this:

$wshell = New-Object -ComObject wscript.shell
$wshell.SendKeys('%{TAB}')

Answer 3

I use this script to do this. Modify as you need...

For example, the default variables $ProcessNameRegEx and $WindowTitleRegEx will move new Notepad windows (just start a couple of them with no file specifed).

You can pass different regex expressions to the script. Edit as makes sense to your needs.

Show-WindowByName

#Requires -RunAsAdministrator

[CmdletBinding()]
param (
    [string]
    $ProcessNameRegEx = 'notepad',

    [string]
    $WindowTitleRegEx = 'unt'
)

$cs = @" 
using System; 
using System.Runtime.InteropServices;

namespace User32
{
    public static class WindowManagement
    {
        [DllImport("user32.dll", EntryPoint = "SetWindowPos")]
        public static extern IntPtr SetWindowPos(IntPtr hWnd, int hWndInsertAfter, int x, int Y, int cx, int cy, int wFlags);

        public const int SWP_NOSIZE = 0x01, SWP_NOMOVE = 0x02, SWP_SHOWWINDOW = 0x40, SWP_HIDEWINDOW = 0x80;

        public static void SetWindowPosWrappoer(IntPtr handle, int x, int y, int width, int height)
        {
            if (handle != null)
            { 
                SetWindowPos(handle, 0, x, y, 0, 0, SWP_NOSIZE | SWP_HIDEWINDOW);

                if (width > -1 && height > -1)
                    SetWindowPos(handle, 0, 0, 0, width, height, SWP_NOMOVE);

                SetWindowPos(handle, 0, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE | SWP_SHOWWINDOW);
            }
        }

        [DllImport("user32.dll", EntryPoint = "ShowWindow")]
        public static extern IntPtr ShowWindow(IntPtr hWnd, int nCmdShow);

        public static void ShowWindowWrapper(IntPtr handle, int nCmdShow)
        {
            if (handle != null)
            { 
                ShowWindow(handle, nCmdShow);
            }
        }

        [DllImport("user32.dll", EntryPoint = "SetForegroundWindow")]
        public static extern IntPtr SetForegroundWindow(IntPtr hWnd);

        public static void SetForegroundWindowWrapper(IntPtr handle)
        {
            if (handle != null)
            { 
                SetForegroundWindow(handle);
            }
        }
    }
}
"@ 

Add-Type -TypeDefinition $cs -Language CSharp -ErrorAction SilentlyContinue


function Move-Window
{
    param (
        [int]$MainWindowHandle,
        [int]$PosX,
        [int]$PosY,
        [int]$Height,
        [int]$Width
    )

    if($MainWindowHandle -ne [System.IntPtr]::Zero)
    {
        [User32.WindowManagement]::SetWindowPosWrappoer($MainWindowHandle, $PosX, $PosY, $Width, $Height);
    }
    else
    {
      throw "Couldn't find the MainWindowHandle, aborting (your process should be still alive)"
    }
}


function Show-Window
{
    param (
        [int]$MainWindowHandle,
        [int]$CmdShow
    )

    if($MainWindowHandle -ne [System.IntPtr]::Zero)
    {
        [User32.WindowManagement]::ShowWindowWrapper($MainWindowHandle, $CmdShow);
        [User32.WindowManagement]::SetForegroundWindowWrapper($MainWindowHandle);
    }
    else
    {
      throw "Couldn't find the MainWindowHandle, aborting (your process should be still alive)"
    }
}


$windows = Get-Process | ? {$_.ProcessName -match $ProcessNameRegEx -and $_.MainWindowTitle -match $WindowTitleRegEx} | Select -Last 100 | Select Id, MainWindowTitle, MainWindowHandle | Sort MainWindowTitle

$h = 180
$w = 1500
$x = 400
$y = 800
$deltax = 80
$deltay = 180

foreach ($window in $windows)
{
    Move-Window $window.MainWindowHandle $x $y $h $w
    Show-Window $window.MainWindowHandle 5
    #$x -= $deltax
    $y -= $deltay
}

Answer 4

<sup>Note:
* This answer in part uses the same technique as the existing answers, but also introduces a new technique, and aims to contrast the approaches in a focused manner, particularly with respect to whether they're also supported in PowerShell Core.
* Only the last solution below - which requires on-demand compilation of C# code via Add-Member - properly activates a window if it happens to be minimized.
* All solutions use PSv4+ syntax; unless explicitly noted, they work in both Windows PowerShell and PowerShell Core (on Windows).</sup>

---

A simpler solution that doesn't require Add-Type with WinAPI P/Invoke signatures is possible, based on the WScript.Shell COM object's .AppActivate() method (which Inventologist's answer hints at):

Note:

• If the target window happens to be minimized, this solution does put the focus on it, but doesn't restore it.

function Show-Window {
  param(
    [Parameter(Mandatory)]
    [string] $ProcessName
  )

  # As a courtesy, strip '.exe' from the name, if present.
  $ProcessName = $ProcessName -replace '\.exe$'

  # Get the ID of the first instance of a process with the given name
  # that has a non-empty window title.
  # NOTE: If multiple instances have visible windows, it is undefined
  #       which one is returned.
  $procId = (Get-Process -ErrorAction Ignore $ProcessName).Where({ $_.MainWindowTitle }, 'First').Id

  if (-not $procId) { Throw "No $ProcessName process with a non-empty window title found." }

  # Note: 
  #  * This can still fail, because the window could have been closed since
  #    the title was obtained.
  #  * If the target window is currently minimized, it gets the *focus*, but is
  #    *not restored*.
  #  * The return value is $true only if the window still existed and was *not
  #    minimized*; this means that returning $false can mean EITHER that the
  #    window doesn't exist OR that it just happened to be minimized.
  $null = (New-Object -ComObject WScript.Shell).AppActivate($procId)

}

# Sample invocation
Show-Window notepad

---

A solution that also restores the target window if it happens to be minimized requires Add-Type with WinAPI P/Invoke declarations:

Note:

• On first invocation of the function in a PowerShell session, there is a noticeable delay due to having to compile the helper type that provides WinAPI access.

• Unlike the solution above, this solution restores a currently minimized window to ensure that its content is visible, while properly activating a currently-maximized window without restoring it.

function Show-Window {
  param(
    [Parameter(Mandatory)]
    [string] $ProcessName
  )

  # As a courtesy, strip '.exe' from the name, if present.
  $ProcessName = $ProcessName -replace '\.exe$'

  # Get the PID of the first instance of a process with the given name
  # that has a non-empty window title.
  # NOTE: If multiple instances have visible windows, it is undefined
  #       which one is returned.
  $hWnd = (Get-Process -ErrorAction Ignore $ProcessName).Where({ $_.MainWindowTitle }, 'First').MainWindowHandle

  if (-not $hWnd) { Throw "No $ProcessName process with a non-empty window title found." }

  $type = Add-Type -PassThru -NameSpace Util -Name SetFgWin -MemberDefinition @'
    [DllImport("user32.dll", SetLastError=true)]
    public static extern bool SetForegroundWindow(IntPtr hWnd);
    [DllImport("user32.dll", SetLastError=true)]
    public static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);    
    [DllImport("user32.dll", SetLastError=true)]
    public static extern bool IsIconic(IntPtr hWnd);    // Is the window minimized?
'@ 

  # Note: 
  #  * This can still fail, because the window could have bee closed since
  #    the title was obtained.
  #  * If the target window is currently minimized, it gets the *focus*, but its
  #    *not restored*.
  $null = $type::SetForegroundWindow($hWnd)
  # If the window is minimized, restore it.
  # Note: We don't call ShowWindow() *unconditionally*, because doing so would
  #       restore a currently *maximized* window instead of activating it in its current state.
  if ($type::IsIconic($hwnd)) {
    $type::ShowWindow($hwnd, 9) # SW_RESTORE
  }

}

# Sample invocation
Show-Window notepad