Showing a window after hiding it

[GRussell31]

Hi,

I've written an application in Vb.Net 2005 which uses the GetProcessesByName function to find all instances of an application which I then want to hide from the user.
I'm using the MainHandleWindow function to return the window handle from each process which I am then passing to the ShowWindow API to hide the window.

This all works fine, and I can happily hide the windows. The problem comes when I try to show the window again! When I call the ShowWindow API with the same window handle that I used to hide nothing happens (the window doesn't appear) and the method call returns 0.

My Code (edited to display here)...

        Dim SW_HIDE As Integer = 0
        Dim SW_SHOW As Integer= 5

        Dim proc As Process() = Process.GetProcessesByName("iexplore")
        Dim iRet, a asInteger
        iRet = CType(proc(0).MainWindowHandle, Integer)
        ' This hides the window
        a = ShowWindow(iRet, SW_HIDE)

        ' This does not make it appear
        a = ShowWindow(iRet, SW_SHOW)

My API Declaration:

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

I'm using windows Vista and trying to hide any Internet Explorer windows.

I just find it strange that it can hide the window but not show it again afterwards.

Can anyone offer any advice?

Thanks,

-Graham

 

[JohnH]

It should work if you're on a 64bit Windows, but the hWnd parameter is type IntPtr, not Long.

 

[GRussell31]

Fantastic thank you!

That'll teach me for using the VB6 API viewer to get the declarations!

Thanks once again,

-Graham