AppActivate and FindWindow

[Edgemeal]

I have used this to invoke the calculator app (by replacing "notepad.exe" with "calc.exe"). It opens the calculator OK if it is not already open but if it is open and minimised, it doesn't maximise the window so to the user, it may appear that nothing is happening. I don't want to kill the process first either in case the user was doing something on the calculator previously. Is there a way to maximise the window if it is minimised?

IsIconic will tell you if window is minimized, ShowWindow will let you change windowstate.. could use GetProcessesByName to get handle also,..

Tested on Windows 7

Imports System.Runtime.InteropServices

Public Class Form1

    <DllImport("user32.dll", CharSet:=CharSet.Auto, SetLastError:=True)>
    Private Shared Function SetForegroundWindow(ByVal hWnd As IntPtr) As Boolean
    End Function

    Private Declare Auto Function IsIconic Lib "user32.dll" (ByVal hwnd As IntPtr) As Boolean

    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
    Private Shared Function ShowWindow(ByVal hwnd As IntPtr, ByVal nCmdShow As Int32) As Boolean
    End Function

    Public Enum ShowWindowCommands As Integer
        'for info on these commands see, http://msdn.microsoft.com/en-us/library/windows/desktop/ms633548%28v=vs.85%29.aspx
        SW_HIDE = 0
        SW_SHOWNORMAL = 1
        SW_NORMAL = 1
        SW_SHOWMINIMIZED = 2
        SW_SHOWMAXIMIZED = 3
        SW_MAXIMIZE = 3
        SW_SHOWNOACTIVATE = 4
        SW_SHOW = 5
        SW_MINIMIZE = 6
        SW_SHOWMINNOACTIVE = 7
        SW_SHOWNA = 8 'similar to SW_SHOW, except the window is not activated.
        SW_RESTORE = 9
        SW_SHOWDEFAULT = 10
        SW_FORCEMINIMIZE = 11       
    End Enum

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim hWnd As IntPtr = GetWindowHandle("Calc.exe")
        If Not hWnd = IntPtr.Zero Then ' found
            ' if minimized then restore.
            If IsIconic(hWnd) Then
                ShowWindow(hWnd, ShowWindowCommands.SW_RESTORE)
            Else
                ' bring to foreground
                SetForegroundWindow(hWnd)
            End If
        Else
            Process.Start("calc.exe")
        End If
    End Sub

    Private Function GetWindowHandle(processName As String) As IntPtr
        processName = System.IO.Path.GetFileNameWithoutExtension(processName)
        Dim p() = Process.GetProcessesByName(processName)
        Return If(p.Length > 0, p(0).MainWindowHandle, IntPtr.Zero)
    End Function

End Class