Do you know how to save a VB Form as JPEG image?

Question

I have a form displaying graph and knob (dial meter) output that is output only. I want to save the form "image" as a JPEG file (or other picture format) so I can display it in a web page for info purposes only. I plan to "refresh/rewrite" the JPEG every minute of so. I have seen software that does this. It is nice for presenting info in the browser (to non wintel machines for example).
Any idea how to do it?
Thanks

Answer 1

Also, if you're using VB.NET, this is pretty easy ... something like this would work:
Private Shared Function BitBlt( _
ByVal hdcDest As IntPtr, _
ByVal nXDest As Integer, _
ByVal nYDest As Integer, _
ByVal nWidth As Integer, _
ByVal nHeight As Integer, _
ByVal hdcSrc As IntPtr, _
ByVal nXSrc As Integer, _
ByVal nYSrc As Integer, _
ByVal dwRop As Integer _
) As Boolean
End Function
Private Shared SRCCOPY As Integer = &HCC0020
Private Sub SaveFormToFile(ByVal sourceForm As Form, ByVal filename As String)
Dim formGraphics As Graphics = sourceForm.CreateGraphics()
Dim
bufferRect = sourceForm.ClientRectangle
Dim buffer As Image = New Bitmap(bufferRect.Width, bufferRect.Height, formGraphics)
Dim bufferGraphics As Graphics = Graphics.FromImage(buffer)
Dim formDC As IntPtr = formGraphics.GetHdc()
Dim bufferDC As IntPtr = bufferGraphics.GetHdc()
BitBlt(bufferDC, 0, 0, bufferRect.Width, bufferRect.Height, formDC, 0, 0, SRCCOPY)
bufferGraphics.ReleaseHdc(bufferDC)
formGraphics.ReleaseHdc(formDC)
bufferGraphics.Dispose()
formGraphics.Dispose()
buffer.Save(filename, System.Drawing.Imaging.ImageFormat.Jpeg)
buffer.Dispose()
End Sub
If you copied and pasted this to your form, you could then save the form to a .jpg file anytime you want by passing the Me reference in for this first parameter and the filename that you want to save it to. For example, if you wanted to create a .jpg file in the root directory of your C drive called "Test.jpg":
SaveFormToFile(Me, "Test.jpg")
- Elton