How do I find out the topmost state of an external window?

Question

4.00/5 (1 vote)

See more:

C#

VB

How can I find out if an external window's topmost state is set to true

Posted 6-Oct-14 1:10am

Craig Haywood

Add a Solution

Comments

Nelek 6-Oct-14 7:13am

What have you tried?[^]

Craig Haywood 6-Oct-14 7:30am

Nothing as yet as I do not know how. That's why I am asking

BillWoodruff 6-Oct-14 7:16am

What exactly do you mean by "external window" ? Is this WinForms ? WPF ? or ... ?

Craig Haywood 6-Oct-14 7:21am

This can be any external window that is not part of my application. Whether it is winforms or wpf is irrelevant. I know how to set the topmost state of an external window as well as how to remove it, but in order to create a toggle function in my application, I first need to get the current topmost state for the external window.

BillWoodruff 6-Oct-14 7:30am

Assuming you are using API code from C# to get a pointer to all open windows, and that you then discriminate which open windows are not your own app's windows ... doesn't the API you are using return some information about the windows state ?

What is your goal here ? To make sure one, or all, of you own app's windows are not behind some external app's windows ?

Craig Haywood 6-Oct-14 7:36am

I am writing an application that amongst other thing will perform global mouse gestures. I want users to be able to assign their own actions to the gestures and also provide a few built in functions.

One of these functions will be to toggle an external window's topmost state. Of course I can have an action that sets the topmost state to true and another that sets it to false. It just seems ridiculous to use two different gestures to do basically the same thing.

If I can find out the topmost state of an external application, then I can use one gesture to toggle it on when it is set to false and off when it is set to true

BillWoodruff 6-Oct-14 9:50am

An interesting pursuit ! I suggest that you take your response to my questions, and revise your original question so it reflects all the information you've given.

And, I suggest you describe the GlobalHook code you are using: did it come from one of the five or so articles about GlobalHook here on CodeProject, like the one by George Mamaladze ?

Craig Haywood 6-Oct-14 10:33am

I am using the global hook at https://globalmousekeyhook.codeplex.com/.

As for my dilemma, from reading a lot of articles, it seems as if I need to use GetWindowLong to find the topmost state of an external app. However, from http://www.pinvoke.net it seems as if this is a mess in vb or c#, especially if used between 32bit and 64bit machines.

Anyway, I have tried it, but GetWindowLong always returns 0 for me.

BillWoodruff 6-Oct-14 11:02am

fyi: the Global Hook code you are using is by George Mamaladze, and it's an evolution of the code in his CP article

http://www.codeproject.com/Articles/7294/Processing-Global-Mouse-and-Keyboard-Hooks-in-C

... that article is still active, and George does sometimes reply to questions/feedback on it.

If I were in your shoes, I'd review all the articles on global hooks here on CP (there's one posted as of August, this year), and look for ideas.

Craig Haywood 6-Oct-14 11:04am

Thanks @BillWoodruff. I am searching global hooks now

Craig Haywood 7-Oct-14 12:59pm

I just want to say thank you to everybody who tried to help. I am not going to waste anymore time on this.

It would be nice if I can use my set topmost function as a toggle topmost on or off but unfortunately it doesn't make sense spending two days researching something I can already do with two different functions as opposed to one.

3 solutions

Solution 2

You can use GetWindowLong with second argument of GWL_EXSTYLE:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms633584%28v=vs.85%29.aspx[^],
http://msdn.microsoft.com/en-us/library/windows/desktop/ff700543(v=vs.85).aspx[^].

AND the result (actual "extended style") with WS_EX_TOPMOST to see if the window in question topmost or not.

—SA

Posted 6-Oct-14 4:27am

Sergey Alexandrovich Kryukov

Updated 6-Oct-14 4:28am

v2

Comments

Craig Haywood 6-Oct-14 10:52am

From everything I have read, this seems to be the approach, in my tests, GetWindowLong always returns 0. Maybe somebody here can get it to work on both 32bit and 64bit machines

Sergey Alexandrovich Kryukov 6-Oct-14 11:40am

It should not return 0. Check up your HWND.
Please see, for 64/32 bit platform compatibility: GetWindowLongPtr.
This function superseded GetWindowLong.
—SA

Craig Haywood 7-Oct-14 3:03am

GetWindowLongPtr gives a first chance exception of type 'System.EntryPointNotFoundException'

Imports System.Runtime.InteropServices

Public Class Form1
<DllImport("user32.dll")> _
Private Shared Function GetWindowLongPtr(ByVal hWnd As IntPtr, ByVal nIndex As Integer) As IntPtr
End Function
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim notepad As Process = Process.GetProcessesByName("notepad")(0)
Dim hWnd As IntPtr = notepad.MainWindowHandle
Dim GWL_EXSTYLE As IntPtr = -20
Dim WS_EX_TOPMOST As IntPtr = 8
Dim Style As IntPtr = GetWindowLongPtr(hWnd, GWL_EXSTYLE)
End Sub
End Class

Sergey Alexandrovich Kryukov 7-Oct-14 11:20am

The API name is GetWindowLongPtrW (Unicode)
—SA

Craig Haywood 7-Oct-14 12:43pm

I'm starting to think this is just not possible in vb or C#

Imports System.Runtime.InteropServices

Public Class Form1
<DllImport("user32.dll", EntryPoint:="GetWindowLongPtrW")> _
Public Shared Function GetWindowLongPtrW(ByVal hWnd As HandleRef, ByVal nIndex As Integer) As IntPtr

End Function
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim notepad As Process = Process.GetProcessesByName("notepad")(0)
Dim hWnd As IntPtr = notepad.MainWindowHandle
Dim notepad2 As New HandleRef(0, hWnd)
Dim Style As IntPtr = GetWindowLongPtrW(notepad2, -20)
MsgBox(Style.ToString)

End Sub
End Class

Additional information: Unable to find an entry point named 'GetWindowLongPtrW' in DLL 'user32.dll'.

Sergey Alexandrovich Kryukov 7-Oct-14 12:47pm

Of course it is possible! Just check up everything thoroughly.
—SA

Sergey Alexandrovich Kryukov 7-Oct-14 12:48pm

This is what Pinvoke.NET tells us:
GetWindowLongPtr.
—SA

Solution 1

Check WS_EX_TOPMOST[^].

You can use EnumChildWindows [^] or GetWindow [^] to get the window you want to check.

Posted 6-Oct-14 1:38am

LNogueira

Comments

Sergey Alexandrovich Kryukov 6-Oct-14 10:31am

That is correct, but OP, who could not find this constant, would be as likely unaware how to check it up, too. Two links on a second line are pretty much irrelevant. It could be any HWND; and we don't know what's on input.

Please see Solution 2.

—SA

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Craig Haywood · Accepted Answer · 2014-10-07T07:04:00

Just want to say thanks to everybody who helped. Just when I was about to give up Sergey pointed me to code I used incorrectly yesterday, just to have success today :-)

VB

Public Class Form1
    <DllImport("user32.dll", EntryPoint:="GetWindowLong")> _
    Private Shared Function GetWindowLongPtr32(ByVal hWnd As HandleRef, ByVal nIndex As Integer) As IntPtr
    End Function

    <DllImport("user32.dll", EntryPoint:="GetWindowLongPtr")> _
    Private Shared Function GetWindowLongPtr64(ByVal hWnd As HandleRef, ByVal nIndex As Integer) As IntPtr
    End Function

    ' This static method is required because Win32 does not support GetWindowLongPtr dirctly
    Public Shared Function GetWindowLongPtr(ByVal hWnd As HandleRef, ByVal nIndex As Integer) As IntPtr
        If IntPtr.Size = 8 Then
            Return GetWindowLongPtr64(hWnd, nIndex)
        Else
            Return GetWindowLongPtr32(hWnd, nIndex)
        End If
    End Function
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        'Dim notepad As Process = Process.GetProcessesByName("notepad")(0)
        'Dim hWnd As IntPtr = notepad.MainWindowHandle
        Dim GWL_EXSTYLE As Integer = -20
        Dim WS_EX_TOPMOST As IntPtr = 8
        'Dim Style As IntPtr = GetWindowLongPtr(hWnd, GWL_EXSTYLE)
        Dim notepad As Process = Process.GetProcessesByName("notepad")(0)
        Dim hWnd As IntPtr = notepad.MainWindowHandle
        Dim notepad2 As New HandleRef(0, hWnd)
        Dim Style As IntPtr = GetWindowLongPtr(notepad2, -20)
        MsgBox(Style.ToString)
    End Sub
End Class

How do I find out the topmost state of an external window?

3 solutions

Solution 2

Solution 3

Solution 1

Add your solution here

Preview 0

Existing Members

...or Join us