Draw Text with hDC/hFont question

Hello,

I need to draw text within a window, but I only have the device context (hDC) for this window. Is there anyway to do this without using win32 API and if not, how do I get a font's hFont in VB .net?

Thanks,

Lloyd

Not sure if this is what you want (I don't know graphics using the API) but it *looks* like it:

ms-help://MS.VSCC/MS.MSDNVS/cpref/html/frlrfSystemDrawingGraphicsClassFromHdcTopic.htm

VB Code:

Public Sub FromHdcHdc(e As PaintEventArgs)
    ' Get handle to device context.
    Dim hdc As IntPtr = e.Graphics.GetHdc()
    ' Create new graphics object using handle to device context.
    Dim newGraphics As Graphics = Graphics.FromHdc(hdc)
    ' Draw rectangle to screen.
    newGraphics.DrawRectangle(New Pen(Color.Red, 3), 0, 0, 200, 100)
    ' Release handle to device context.
    e.Graphics.ReleaseHdc(hdc)
End Sub

For fonts, the Font object exposes a .ToHfont method:

ms-help://MS.VSCC/MS.MSDNVS/cpref/html/frlrfSystemDrawingFontClassToHfontTopic.htm

OK... Thanks for your help. It looks like you may have something there.

However, this brings up another question. How do I convert an Integer (Int32) to IntPtr? The hDC is being passed as an Integer (and that can't be changed), therefore I get "Value type of 'Integer' cannot be converted to 'System.IntPtr'" on this line:

VB Code:

Dim gpxResult As Graphics = Graphics.FromHdc(hDC)

Thanks,

Lloyd

OK... I found IntPtr.op_Explicit to convert the Integer to IntPtr.

Now to contiue on with the drawing aspect... I will let you know how it goes.

First , GDI+ contains most of the API calls with very ease of use . So make APIs your last option . Anywasy , I wanted to write this little demo to get you started . Hope it's what you are looking for .

VB Code:

Protected Overrides Sub OnPaint(ByVal e As _
System.Windows.Forms.PaintEventArgs)
        'Device Context
        Dim dc As Graphics = e.Graphics
 
        'The string we are going to write
        Dim drawString As String = "Pirate"
 
        'Font we'll use 
        Dim drawFont As New Font("Arial", 20, FontStyle.Bold)
 
        'Brush used to write the text supported with 
        'different colors 
        Dim myBrush As New Drawing2D.LinearGradientBrush(ClientRectangle, _
        Color.Yellow, Color.Blue, Drawing2D.LinearGradientMode.Horizontal)
 
        'Check FormatFlags Enums to see different drawing styles 
        'you can use.
        Dim drawFormat As New StringFormat()
        drawFormat.FormatFlags = StringFormatFlags.NoFontFallback
 
        'this explain itself :)
        Dim x As Integer = 150
        Dim y As Integer = 50
 
        'Finally we apply the Drwaing on the form .
        dc.DrawString(drawString, drawFont, myBrush, _
        x, y, drawFormat)
        'Enjoy 
    End Sub

Thanks for the example. I actually, had good success with creating a Graphics object from the hdc (Device Context). I was able to reduce nearly 60 lines of code to 30 in one procedure! And I've got 5 more similar functions that draw pie graphs and stacked bar graphs yet! Hey .NET is awsome! :-)