How do I differentiate between a process running & an app visible on screen

Question

Norton Security is part of Windows start up, therefore it is always running as a process.
If a user selects Norton icon on desktop, Norton window appears.
On closing the window it only hides the window as distinct from closing the app. (because it is always running)
I need to determine if the user has woken the app to show on the screen & also know when the app is not visible on the screen when the user closes the app.
ie, What is code to indicate the app screen is visible or not visible

Answer 1

For applications that use multiple processes (e.g., chrome, firefox, etc.) there is no guarantee the FirstOrDefault() will return a process where Process.MainWindowHandle contains a valid Window handle. For example, consider the following console application -

Module Module1  
  
    <DllImport("user32.dll", SetLastError:=True)>  
    Function IsWindowVisible(ByVal hWnd As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean  
    End Function  
  
    Sub Main()  
        Dim procs As Process() = Process.GetProcessesByName("Firefox")  
        For Each proc As Process In procs  
            If proc.MainWindowHandle <> 0 Then  
                Console.WriteLine("Firefox process id {0} MainWindowHandle visible: {1}", proc.Id, IsWindowVisible(proc.MainWindowHandle))  
            Else  
                Console.WriteLine("Firefox process id {0} MainWindowHandle is 0", proc.Id)  
            End If  
        Next  
  
    End Sub  
  
End Module  
  

Task manager showing the Firefox processes -

Console application output -

Answer 2

@x38class-9313 , based on my research, I suggest that you could try the Windows API IsWindowVisible function to check if the app is visible or not.

I make a sample wpf app like your Norton Security.

Here is a code example you could refer to.

 <DllImport("user32.dll", SetLastError:=True)>  
Private Shared Function IsWindowVisible(ByVal hWnd As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean  
End Function  
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click  
    Dim currentProcess As Process = Process.GetProcessesByName("WpfApp1").FirstOrDefault()  
    Dim t As Boolean = IsWindowVisible(currentProcess.MainWindowHandle)  
    MessageBox.Show(t.ToString())  
  
End Sub  

Result:

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Answer 3

Again, thanks for a further suggestion, however as I said before, "Norton Security" is always running so using task manager is not an option.

this code has no fault:
Dim currentProcess As Process = Process.GetProcessesByName("chrome")

however:
Dim currentProcess As Process = Process.GetProcessesByName("chrome").FirstOrDefault()

fails because there is no "FirstOrDefault()" option to add to this line of code

your example seems everything I want except for this extension at the end of line that is not available, ie .FirstOrDefault()

Answer 4

RLWA32-6355, Thanks for that, works fine for me as I just tested it, now to put it to a real test in my Release to users.

I dont see where I can credit you with accepting your answer

For, JackJJun-MSFT, obviously you have put in some effort to try & solve for me, much appreciated

Answer 5

Whilst I have tested and accepted an answer, I find for my purpose there is an issue where there is more than one instance of the process, to resolve this I have decided on using the following which should take care of more than one process running, hope it may be useful to others

Dim K As Byte
Dim J As Byte
Dim Status(10) As String
Dim Result As String

    Dim prog As New Process
    For Each prog In Process.GetProcesses
        If UCase(prog.ProcessName) = UCase("NortonSecurity") Then
            K += 1
            Dim t As Boolean = IsWindowVisible(prog.MainWindowHandle)
            Status(K) = t.ToString()
        End If
    Next

    For J = 1 To K
        If Status(J) = "True" Then
            Result = Status(J)
            Exit For
        End If
    Next

    If Result = "" Then
        MsgBox("Not Visible")
    Else
        MsgBox("Visible")
    End If