Workaround for controls display issues in 96 versus 120 dpi

In this topic

• About the controls display issue in 96 versus 120 dpi
• Workaround 1—Using the TableLayoutPanel control
• Workaround 2—Dynamically resizing ActiveX controls at run time

About the controls display issue in 96 versus 120 dpi

When the same application is started and run with the display set to 120 dpi, the two PictureBox controls scale correctly, whereas the ActiveX controls do not. The effect is that the controls overlap each other and the application looks incorrect at design time and run time. See the following screen shot:

Workaround 1—Using the TableLayoutPanel control

Workaround 2—Dynamically resizing ActiveX controls at run time

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    'Call AdjustBounds on each ActiveX control on the form.
    AdjustBounds(Me.AxATLTestControl1)
    AdjustBounds(Me.AxATLTestControl2)
End Sub

Private Sub AdjustBounds(ByVal controlToAdjust As AxHost)
    If Me.CurrentAutoScaleDimensions.Width <> 6.0! Then
        'Adjust location: The ActiveX control doesn't do this by itself.
        controlToAdjust.Left=controlToAdjust.Left * Me.CurrentAutoScaleDimensions.Width / 6.0!
        'Undo the automatic resize...
        controlToAdjust.Width=controlToAdjust.Width / DPIX() * 96
        '...and apply the appropriate resize.
        controlToAdjust.Width=controlToAdjust.Width * Me.CurrentAutoScaleDimensions.Width / 6.0!
    End If
    If Me.CurrentAutoScaleDimensions.Height <> 13.0! Then
        'Adjust location: The ActiveX control doesn't do this by itself.
        controlToAdjust.Top=controlToAdjust.Top * Me.CurrentAutoScaleDimensions.Height / 13.0!
        'Undo the automatic resize...
        controlToAdjust.Height=controlToAdjust.Height / DPIY() * 96
        '...and apply the appropriate resize.
        controlToAdjust.Height=controlToAdjust.Height * Me.CurrentAutoScaleDimensions.Height / 13.0!
    End If
End Sub

<Runtime.InteropServices.DllImport("Gdi32.dll")> _
                                   Private Shared Function GetDeviceCaps(ByVal hDC As IntPtr, ByVal nIndex As Integer) As Integer
End Function

<Runtime.InteropServices.DllImport("Gdi32.dll")> _
                                   Private Shared Function CreateDC(ByVal lpszDriver As String, ByVal lpszDeviceName As String, ByVal lpszOutput As String, ByVal devMode As IntPtr) As IntPtr
End Function

Const LOGPIXELSX As Integer=88
Const LOGPIXELSY As Integer=90

Function DPIX() As Integer
    Return DPI(LOGPIXELSX)
End Function

Function DPIY() As Integer
    Return DPI(LOGPIXELSY)
End Function

Function DPI(ByVal logPixelOrientation As Integer)
    Dim displayPointer=CreateDC("DISPLAY", Nothing, Nothing, IntPtr.Zero)
    Return GetDeviceCaps(displayPointer, logPixelOrientation)
End Function

private void Form1_Load(object sender, EventArgs e)
{
    //Call AdjustBounds on each ActiveX control on the form.
    AdjustBounds(this.axATLTestControl1);
    AdjustBounds(this.axATLTestControl2);
}

private void AdjustBounds(AxHost controlToAdjust)
{
    if (this.CurrentAutoScaleDimensions.Width != 6F)
    {
        //Adjust location: The ActiveX control doesn't do this by itself. 
        controlToAdjust.Left=Convert.ToInt32(controlToAdjust.Left *
            this.CurrentAutoScaleDimensions.Width / 6F);
        //Undo the automatic resize... 
        controlToAdjust.Width=controlToAdjust.Width / DPIX() * 96;
        //...and apply the appropriate resize.
        controlToAdjust.Width=Convert.ToInt32(controlToAdjust.Width *
            this.CurrentAutoScaleDimensions.Width / 6F);
    }
    if (this.CurrentAutoScaleDimensions.Height != 13F)
    {
        //Adjust location: The ActiveX control doesn't do this by itself. 
        controlToAdjust.Top=Convert.ToInt32(controlToAdjust.Top *
            this.CurrentAutoScaleDimensions.Height / 13F);
        //Undo the automatic resize... 
        controlToAdjust.Height=controlToAdjust.Height / DPIY() * 96;
        //...and apply the appropriate resize. 
        controlToAdjust.Height=Convert.ToInt32(controlToAdjust.Height *
            this.CurrentAutoScaleDimensions.Height / 13F);
    }
}

[System.Runtime.InteropServices.DllImport("Gdi32.dll")] static extern int
    GetDeviceCaps(IntPtr hDC, int nIndex);

[System.Runtime.InteropServices.DllImport("Gdi32.dll")] static extern IntPtr
    CreateDC(string lpszDriver, string lpszDeviceName, string lpszOutput, IntPtr
    devMode);

const int LOGPIXELSX=88;
const int LOGPIXELSY=90;

int DPIX()
{
    return DPI(LOGPIXELSX);
}

int DPIY()
{
    return DPI(LOGPIXELSY);
}

int DPI(int logPixelOrientation)
{
    IntPtr displayPointer=CreateDC("DISPLAY", null, null, IntPtr.Zero);
    return Convert.ToInt32(GetDeviceCaps(displayPointer, logPixelOrientation));
}

See Also: