screen width

[yosef_mreh]

hi all
i have 2 monitors pluged. i want my application to run on moniter 2.
how can i do this or how can i know if 2 monitros plugd or 1 moniter

it will be more bitter to know if i have (1 or 2) becuase if i have only 1 moniter i want the application to run on it.

[Jim Davis]

This is quite complex, but i'm not sure that there is any simple way. It is better to place all these things into a Module, you can call anytime.

Retrieving information about your dual monitor setup can be done with the code below.

Option Explicit

Public Declare Function LoadLibraryEx Lib "kernel32.dll" Alias "LoadLibraryExA" (ByVal lpFileName As String, ByVal hFile As Long, ByVal dwFlags As Long) As Long
Public Declare Function GetProcAddress Lib "kernel32.dll" (ByVal hModule As Long, ByVal lpProcName As String) As Long
Public Declare Function GetModuleHandle Lib "kernel32.dll" Alias "GetModuleHandleA" (ByVal lpModuleName As String) As Long
Public Declare Function FreeLibrary Lib "kernel32.dll" (ByVal hLibModule As Long) As Boolean
Public Declare Function EnumDisplayMonitors Lib "user32.dll" (ByVal hdc As Long, ByRef lprcClip As Any, ByVal lpfnEnum As Long, ByVal dwData As Long) As Boolean
Public Declare Function GetMonitorInfo Lib "user32.dll" Alias "GetMonitorInfoA" (ByVal hMonitor As Long, ByRef lpmi As MONITORINFOEX) As Boolean

Public Const CCHDEVICENAME = 32
Public Const MONITORINFOF_PRIMARY = &H1

Public Type RECT
    Left As Long
    Top As Long
    Right As Long
    Bottom As Long
End Type

Public Type MONITORINFOEX
    cbSize As Long
    rcMonitor As RECT
    rcWork As RECT
    dwFlags As Long
    szDevice As String * CCHDEVICENAME
End Type

Dim MonitorId() As String

Public Sub Test()
' At the bottom I have pasted the results on my system.
Dim i As Integer
    Debug.Print "Number of monitors in this system : " & GetMonitorId
    Debug.Print
    For i = 1 To UBound(MonitorId)
        PrintMonitorInfo (MonitorId(i))
    Next i
End Sub

Public Function GetMonitorId()
    ReDim MonitorId(0)
    ' Of course dual screen systems are not available on all Win versions.
    If FunctionExist("user32.dll", "EnumDisplayMonitors") = True Then
        If EnumDisplayMonitors(&H0, ByVal &H0, AddressOf MonitorEnumProc, &H0) = False Then
            Failed "EnumDisplayMonitors"
        End If
    End If
    GetMonitorId = UBound(MonitorId)
End Function


Private Sub PrintMonitorInfo(ForMonitorID As String)
Dim MONITORINFOEX As MONITORINFOEX
    MONITORINFOEX.cbSize = Len(MONITORINFOEX)
    If GetMonitorInfo(CLng(ForMonitorID), MONITORINFOEX) = False Then Failed "GetMonitorInfo"
    With MONITORINFOEX
        Debug.Print "Monitor info for device number : " & ForMonitorID
        Debug.Print "---------------------------------------------------"
        Debug.Print "Device Name : " & .szDevice
        If .dwFlags And MONITORINFOF_PRIMARY Then Debug.Print "Primary Display = True" Else Debug.Print "Primary Display = False"
        With .rcMonitor
            Debug.Print "Monitor Left : " & .Left
            Debug.Print "Monitor Top : " & .Top
            Debug.Print "Monitor Right : " & .Right
            Debug.Print "Monitor Bottom : " & .Bottom
        End With
        With .rcWork
            Debug.Print "Work area Left : " & .Left
            Debug.Print "Work area Top : " & .Top
            Debug.Print "Work area Right : " & .Right
            Debug.Print "Work area Bottom : " & .Bottom
        End With
    End With
    Debug.Print
    Debug.Print
End Sub


Public Function FunctionExist(ByVal strModule As String, ByVal strFunction As String) As Boolean
Dim hHandle As Long
    hHandle = GetModuleHandle(strModule)
    If hHandle = &H0 Then
        Failed "GetModuleHandle"
        hHandle = LoadLibraryEx(strModule, &H0, &H0): If hHandle = &H0 Then Failed "LoadLibrary"
        If GetProcAddress(hHandle, strFunction) = &H0 Then
            Failed "GetProcAddress"
        Else
            FunctionExist = True
        End If
        If FreeLibrary(hHandle) = False Then Failed "FreeLibrary"
    Else
        If GetProcAddress(hHandle, strFunction) = &H0 Then
            Failed "GetProcAddress"
        Else
            FunctionExist = True
        End If
    End If
End Function


Public Sub Failed(ByVal strFunction As String)
    If errMsg = True Then
        If Err.LastDllError = 0 Then
            MessageBoxEx &H0, strFunction & Chr$(13) & Chr$(10) & Chr$(13) & Chr$(10) & "Failed", "Error", MB_OK Or MB_ICONWARNING Or MB_SETFOREGROUND, 0
        Else
            Errors Err.LastDllError, strFunction
        End If
    End If
End Sub


Public Function MonitorEnumProc(ByVal hMonitor As Long, ByVal hdcMonitor As Long, ByRef lprcMonitor As RECT, ByVal dwData As Long) As Boolean
Dim ub As Integer
    ub = 0
    On Error Resume Next
    ub = UBound(MonitorId)
    On Error GoTo 0
    ReDim Preserve MonitorId(ub + 1)
    MonitorId(UBound(MonitorId)) = CStr(hMonitor)
    MonitorEnumProc = 1
End Function

[westconn1]

thanks for the code jim, i can use that

[Merri]

I tried to use Windows Scripting Host to provide me information about the monitors, but it seems it doesn't work as expected. For me it simply didn't give information about all the displays that I had active (external "Generic Television" + laptop "Standard Display"), instead I always only got information on the display that was active when I first started ("Generic Television").

So here is the code for those who want to check it out, it is short'n'sweet:

Option Explicit

' http://msdn.microsoft.com/en-us/library/aa394122(VS.85).aspx
Public Function Monitors() As Object
    ' get scripting object and make a call to scripting host to get the monitors
    Set Monitors = GetObject("winmgmts:\\.\root\CIMV2").ExecQuery("SELECT * FROM Win32_DesktopMonitor")
End Function

Private Sub Command1_Click()
    Dim objMonitor As Object
    ' this loop makes a single call to Monitors function to receive information about the monitors
    For Each objMonitor In Monitors
        ' display information in a message box
        MsgBox "Resolution: " & objMonitor.ScreenWidth & " x " & objMonitor.ScreenHeight & vbNewLine & objMonitor.Availability, vbInformation, objMonitor.Description
    Next objMonitor
End Sub