How to activate an existing program

microsoft.public.dotnet.framework

2 Nov 2006 12:12 AM

Bob Altman

Hi all,

I need to activate a running Windows application from my .Net application.
(I want to display the application's main form if it's minimized and try to
give it focus.) For example:

Dim procs() as Process = Process.GetProcessesByName("SomeApp")
If procs.Length > 0 Then
Procs(0).Activate
End If

Of course, the Process class doesn't expose an Activate method. My question
is: Is there anything baked into .Net that does this, or do I need to get
the unmanaged process handle and fiddle around with Windows API calls?

TIA - Bob

2 Nov 2006 1:35 AM

Kevin Yu [MSFT]

Hi Bob,

First of all, I would like to confirm my understanding of your issue. From
your description, I understand that you need to get the main windows of a
certain process, and show it in foreground. If there is any
misunderstanding, please feel free to let me know.

In this, we have to accomplish 2 things.

1. Get the main window of the process. If the window is minimized, show it
as normal.
2. If the window is in background, bring it to front.

In this case, we have to use P/Invoke with 2 functions. ShowWindow and
SetForegroundWindow. Here is an example.

Imports System.Diagnostics
Imports System.Runtime.InteropServices

Public Class Form1

    <DllImport("user32.dll")> _
    Shared Function SetForegroundWindow(ByVal hWnd As IntPtr) _
        As <MarshalAs(UnmanagedType.Bool)> Boolean
    End Function

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

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
        Dim procs() As Process = Process.GetProcessesByName("RedAlerter")
        If procs.Length > 0 Then
            Form1.ShowWindow(procs(0).MainWindowHandle, 1)
            Form1.SetForegroundWindow(procs(0).MainWindowHandle)
        End If
    End Sub
End Class

If anything is unclear, please feel free to reply to the post.

Kevin Yu
Microsoft Online Community Support

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2 Nov 2006 4:08 AM

Lau Lei Cheong

Actually, depending on what program you're going to run, there is a third
way.

If the program is a signle-instance program, running it again will
re-activate it. (Try running Outlook.exe again when it's minimized)

Show quote

"Kevin Yu [MSFT]" <v-k***@online.microsoft.com> ¼¶¼g©ó¶l¥ó·s»D:EI1ar8h$GHA.5***@TK2MSFTNGXA01.phx.gbl...
> Hi Bob,
>
> First of all, I would like to confirm my understanding of your issue. From
> your description, I understand that you need to get the main windows of a
> certain process, and show it in foreground. If there is any
> misunderstanding, please feel free to let me know.
>
> In this, we have to accomplish 2 things.
>
> 1. Get the main window of the process. If the window is minimized, show it
> as normal.
> 2. If the window is in background, bring it to front.
>

2 Nov 2006 11:43 PM

Bob Altman

Thanks Kevin, that works like a champ!

- Bob

Show quote

"Kevin Yu [MSFT]" <v-k***@online.microsoft.com> wrote in message
news:EI1ar8h$GHA.5920@TK2MSFTNGXA01.phx.gbl...
> Hi Bob,
>
> First of all, I would like to confirm my understanding of your issue. From
> your description, I understand that you need to get the main windows of a
> certain process, and show it in foreground. If there is any
> misunderstanding, please feel free to let me know.
>
> In this, we have to accomplish 2 things.
>
> 1. Get the main window of the process. If the window is minimized, show it
> as normal.
> 2. If the window is in background, bring it to front.
>
> In this case, we have to use P/Invoke with 2 functions. ShowWindow and
> SetForegroundWindow. Here is an example.
>
> Imports System.Diagnostics
> Imports System.Runtime.InteropServices
>
> Public Class Form1
>
>    <DllImport("user32.dll")> _
>    Shared Function SetForegroundWindow(ByVal hWnd As IntPtr) _
>        As <MarshalAs(UnmanagedType.Bool)> Boolean
>    End Function
>
>    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
>    Shared Function ShowWindow(ByVal hwnd As IntPtr, ByVal nCmdShow As
> Int32) As Long
>    End Function
>
>    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
> System.EventArgs) Handles Button1.Click
>        Dim procs() As Process = Process.GetProcessesByName("RedAlerter")
>        If procs.Length > 0 Then
>            Form1.ShowWindow(procs(0).MainWindowHandle, 1)
>            Form1.SetForegroundWindow(procs(0).MainWindowHandle)
>        End If
>    End Sub
> End Class
>
> If anything is unclear, please feel free to reply to the post.
>
> Kevin Yu
> Microsoft Online Community Support
>
> ==================================================
> Get notification to my posts through email? Please refer to
> http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif
> ications.
> Note: The MSDN Managed Newsgroup support offering is for non-urgent issues
> where an initial response from the community or a Microsoft Support
> Engineer within 1 business day is acceptable. Please note that each follow
> up response may take approximately 2 business days as the support
> professional working with you may need further investigation to reach the
> most efficient resolution. The offering is not appropriate for situations
> that require urgent, real-time or phone-based interactions or complex
> project analysis and dump analysis issues. Issues of this nature are best
> handled working with a dedicated Microsoft Support Engineer by contacting
> Microsoft Customer Support Services (CSS) at
> http://msdn.microsoft.com/subscriptions/support/default.aspx.
> ==================================================
>
> (This posting is provided "AS IS", with no warranties, and confers no
> rights.)
>