how do i get DPI of system

[su ki]

hey

is there any way to determine DPI of system ?

[sparrow1]

Hi,

You can try something like this;

Public Shared Function GetResolution(ByVal visual As Visual) As Point
       Dim dpi As New Point(120, 120)
      
       Dim source As PresentationSource = PresentationSource.FromVisual(visual)
       If source Is Nothing Then
           Return dpi
       End If
     
       Dim target As CompositionTarget = source.CompositionTarget
     
       Dim m As Matrix = target.TransformToDevice
       Dim t As New MatrixTransform(m)
     
      Dim pt1 As New Point(0, 0)
       pt1 = t.Transform(pt1)
      
     Dim pt2 As New Point(96, 96)
     pt2 = t.Transform(pt2)
     
     dpi.X = pt2.X - pt1.X
       dpi.Y = pt2.Y - pt1.Y
      Return dpi
   End Function

[Negative0]

Try this:

        Dim g As Graphics = Me.CreateGraphics
        MessageBox.Show(String.Format("{0}x{1}", g.DpiX.ToString(), g.DpiY.ToString()))
        g.Dispose()

[su ki]

hey
@Negative0 this doesnot work for me

MessageBox.Show(String.Format("{0}x{1}", g.DpiX.ToString(), g.DpiY.ToString()))

@sparrow1
is there namespaces and refrences required as i am getting error in visual ??

ByVal visual As Visual

Type 'Visual' is not defined.
Type 'PresentationSource' is not defined.
Type 'CompositionTarget' is not defined.
Type 'Matrix' is not defined.
Type 'MatrixTransform' is not defined.

pls help

[Pino]

Yes,

System.Windows
System.Windows.Media

Think thats all you need.

[Negative0]

Can you explain what doesn't work? It worked perfectly on my machine, returning 96x96. What did it return on your machine? What are you expecting it to return?

[ForumAccount]

Can you explain what doesn't work? It worked perfectly on my machine, returning 96x96. What did it return on your machine? What are you expecting it to return?

Works for me too.

[dbasnett]

Imports System
Imports System.Management
Imports System.Windows.Forms

Namespace WMISample

    Public Class MyWMIQuery

        Public Overloads Shared Function Main() As Integer

            Try
                Dim searcher As New ManagementObjectSearcher( _
                    "root\CIMV2", _
                    "SELECT * FROM Win32_DisplayConfiguration") 

                For Each queryObj As ManagementObject in searcher.Get()

                    Console.WriteLine("-----------------------------------")
                    Console.WriteLine("Win32_DisplayConfiguration instance")
                    Console.WriteLine("-----------------------------------")
                    Console.WriteLine("LogPixels: {0}", queryObj("LogPixels"))
                Next
            Catch err As ManagementException
                MessageBox.Show("An error occurred while querying for WMI data: " & err.Message)
            End Try
        End Function
    End Class
End Namespace

or

Imports System
Imports System.Management
Imports System.Windows.Forms

Namespace WMISample

    Public Class MyWMIQuery

        Public Overloads Shared Function Main() As Integer

            Try
                Dim searcher As New ManagementObjectSearcher( _
                    "root\CIMV2", _
                    "SELECT * FROM Win32_DisplayControllerConfiguration") 

                For Each queryObj As ManagementObject in searcher.Get()

                    Console.WriteLine("-----------------------------------")
                    Console.WriteLine("Win32_DisplayControllerConfiguration instance")
                    Console.WriteLine("-----------------------------------")
                    Console.WriteLine("HorizontalResolution: {0}", queryObj("HorizontalResolution"))
                    Console.WriteLine("VerticalResolution: {0}", queryObj("VerticalResolution"))
                Next
            Catch err As ManagementException
                MessageBox.Show("An error occurred while querying for WMI data: " & err.Message)
            End Try
        End Function
    End Class
End Namespace

or

Imports System
Imports System.Management
Imports System.Windows.Forms

Namespace WMISample

    Public Class MyWMIQuery

        Public Overloads Shared Function Main() As Integer

            Try
                Dim searcher As New ManagementObjectSearcher( _
                    "root\CIMV2", _
                    "SELECT * FROM Win32_VideoController") 

                For Each queryObj As ManagementObject in searcher.Get()

                    Console.WriteLine("-----------------------------------")
                    Console.WriteLine("Win32_VideoController instance")
                    Console.WriteLine("-----------------------------------")
                    Console.WriteLine("CurrentHorizontalResolution: {0}", queryObj("CurrentHorizontalResolution"))
                    Console.WriteLine("CurrentVerticalResolution: {0}", queryObj("CurrentVerticalResolution"))
                Next
            Catch err As ManagementException
                MessageBox.Show("An error occurred while querying for WMI data: " & err.Message)
            End Try
        End Function
    End Class
End Namespace

[Negative0]

Well resolution is not the same as DPI. DPI is a setting you can change to make the fonts larger without changing your resolution.

If you just want the resolution, there is no need for WMI, you can use the My.Computer.Screen objecT:

MessageBox.Show(String.Format("{0}x{1}", My.Computer.Screen.Bounds.Width.ToString(), My.Computer.Screen.Bounds.Height.ToString()))

[su ki]

hey

*@ Pino thanks for telling about required namespaces.

@Negative0 , it shows 96 when dpi setting is 96 but it doesnot change when i switch it to 120 which it suppose to be.

actually i am checking it on resolution 1920*1200 and dpi 96 or 120

i understand that resolution is not same as dpi

@dbasnett , i hv not checked ur solution as i was not on my pc , let u know soon

su ki