Question: Saving form as jpeg or gif automatically

[VB Programmer]

Briefly, how do you save the current form to a jpeg or gif?

Details: I have a form with a speedometer control on it. It continually
loops through a table in a db that has different current "speeds". I want
to "set" the speedometer to the current speed, then save the form as a
picture, then go to the next one, etc... The end result would be a gif or
jpeg that has a "snapshot" of the gauge. (This would eventually show up on
a aspx webform in an image control.)

Any ideas?

Thanks!

[Nice Chap]

This link is from an earlier post

<http://groups.google.de/groups?q=gro...=de&lr=&ie=UTF
-8&selm=cuwHx16C CHA.1908%40cpms ftngxa07&rnum=1 >

"VB Programmer" <gr*********@ go-intech.com> wrote in message
news:O9******** ******@tk2msftn gp13.phx.gbl...

Briefly, how do you save the current form to a jpeg or gif?

Details: I have a form with a speedometer control on it. It continually
loops through a table in a db that has different current "speeds". I want
to "set" the speedometer to the current speed, then save the form as a
picture, then go to the next one, etc... The end result would be a gif or
jpeg that has a "snapshot" of the gauge. (This would eventually show up on a aspx webform in an image control.)

Any ideas?

Thanks!

[Fergus Cooney]

Hi VBP

The code below will capture the given Control's imagery and return a
BitMap.

You can the use bmp.Save (sFilePath, Imaging.ImageFo rmat.Whatever)

Credit to Armin for this one - I think I got it from one of his posts
elsewhere.

Regards,
Fergus

<code>
Public Declare Function BitBlt Lib "gdi32" ( _
ByVal hDestDC As IntPtr, _
ByVal x As Integer, _
ByVal y As Integer, _
ByVal nWidth As Integer, _
ByVal nHeight As Integer, _
ByVal hSrcDC As IntPtr, _
ByVal xSrc As Integer, _
ByVal ySrc As Integer, _
ByVal dwRop As Integer _
) As Integer

'============== =============== =============== =============== ========
Public Function CaptureControl( ByVal c As Control) As Bitmap

Dim bmp As Bitmap
Dim gDest, gSource As Graphics
Dim hdcSource, hdcDest As IntPtr

bmp = New Bitmap(c.Width, c.Height)

gSource = c.CreateGraphic s
Try
gDest = Graphics.FromIm age(bmp)
Try
hdcSource = gSource.GetHdc
Try
hdcDest = gDest.GetHdc
Try
BitBlt( _
hdcDest, 0, 0, _
c.Width, c.Height, _
hdcSource, 0, 0, SRCCOPY _
)
Finally
gDest.ReleaseHd c(hdcDest)
End Try
Finally
gSource.Release Hdc(hdcSource)
End Try
Finally
gDest.Dispose()
End Try
Finally
gSource.Dispose ()
End Try

Return bmp
End Function
</code>

[VB Programmer]

AWESOME! Thanks!
"Fergus Cooney" <fi******@tesco .net> wrote in message
news:Oe******** ******@tk2msftn gp13.phx.gbl...

Hi VBP

The code below will capture the given Control's imagery and return a
BitMap.

You can the use bmp.Save (sFilePath, Imaging.ImageFo rmat.Whatever)

Credit to Armin for this one - I think I got it from one of his posts
elsewhere.

Regards,
Fergus

<code>
Public Declare Function BitBlt Lib "gdi32" ( _
ByVal hDestDC As IntPtr, _
ByVal x As Integer, _
ByVal y As Integer, _
ByVal nWidth As Integer, _
ByVal nHeight As Integer, _
ByVal hSrcDC As IntPtr, _
ByVal xSrc As Integer, _
ByVal ySrc As Integer, _
ByVal dwRop As Integer _
) As Integer

'============== =============== =============== =============== ========
Public Function CaptureControl( ByVal c As Control) As Bitmap

Dim bmp As Bitmap
Dim gDest, gSource As Graphics
Dim hdcSource, hdcDest As IntPtr

bmp = New Bitmap(c.Width, c.Height)

gSource = c.CreateGraphic s
Try
gDest = Graphics.FromIm age(bmp)
Try
hdcSource = gSource.GetHdc
Try
hdcDest = gDest.GetHdc
Try
BitBlt( _
hdcDest, 0, 0, _
c.Width, c.Height, _
hdcSource, 0, 0, SRCCOPY _
)
Finally
gDest.ReleaseHd c(hdcDest)
End Try
Finally
gSource.Release Hdc(hdcSource)
End Try
Finally
gDest.Dispose()
End Try
Finally
gSource.Dispose ()
End Try

Return bmp
End Function
</code>

[VB Programmer]

3 quick questions...

I put a button on my winform and tried to call your CaptureControl function
but it kept giving me a "Invalid parameter used" error (unhandled exception
in system.drawing. dll) for the Dim line. Here's the code:

Private Sub Button1_Click(B yVal sender As System.Object, ByVal e As
System.EventArg s) Handles Button1.Click
Dim x As New Bitmap("zzz.bmp ")
x = CaptureControl( Me)
End Sub

1. Any ideas? Am I invoking this correctly?
2. Also, it says I have to declare SRCCOPY. Do I just declare it as an
integer?
3. What is BitBlt? I don't see any code? Where is the code?

Thanks.

"Fergus Cooney" <fi******@tesco .net> wrote in message
news:Oe******** ******@tk2msftn gp13.phx.gbl...

Hi VBP

The code below will capture the given Control's imagery and return a
BitMap.

You can the use bmp.Save (sFilePath, Imaging.ImageFo rmat.Whatever)

Credit to Armin for this one - I think I got it from one of his posts
elsewhere.

Regards,
Fergus

<code>
Public Declare Function BitBlt Lib "gdi32" ( _
ByVal hDestDC As IntPtr, _
ByVal x As Integer, _
ByVal y As Integer, _
ByVal nWidth As Integer, _
ByVal nHeight As Integer, _
ByVal hSrcDC As IntPtr, _
ByVal xSrc As Integer, _
ByVal ySrc As Integer, _
ByVal dwRop As Integer _
) As Integer

'============== =============== =============== =============== ========
Public Function CaptureControl( ByVal c As Control) As Bitmap

Dim bmp As Bitmap
Dim gDest, gSource As Graphics
Dim hdcSource, hdcDest As IntPtr

bmp = New Bitmap(c.Width, c.Height)

gSource = c.CreateGraphic s
Try
gDest = Graphics.FromIm age(bmp)
Try
hdcSource = gSource.GetHdc
Try
hdcDest = gDest.GetHdc
Try
BitBlt( _
hdcDest, 0, 0, _
c.Width, c.Height, _
hdcSource, 0, 0, SRCCOPY _
)
Finally
gDest.ReleaseHd c(hdcDest)
End Try
Finally
gSource.Release Hdc(hdcSource)
End Try
Finally
gDest.Dispose()
End Try
Finally
gSource.Dispose ()
End Try

Return bmp
End Function
</code>

[Fergus Cooney]

Hi VBP,

Sorry, I forgot to copy SRCCOPY across.
Const SRCCOPY As Integer = &HCC0020

BitBlt is part of the WinApi, specifically the GDI dll.
This is shown by the declaration:
Public Declare Function BitBlt Lib "gdi32" ( ...) As Integer
The Declare part tells the compiler that there's going to be mention of a
function BitBlt but that the code isn't going to be given at this time. The
Lib "gdi32" part tells it to find the actual routine externally.

Try this.
Dim x As New Bitmap 'Just to say that you want a BitMap
x = CaptureControl( Me)
x.Save ("zzz.bmp", Imaging.ImageFo rmat.Bmp)

Regards,
Fergus

[VB Programmer]

Thanks. Awesome responses!

"Fergus Cooney" <fi******@tesco .net> wrote in message
news:eu******** ******@TK2MSFTN GP11.phx.gbl...

Hi VBP,

Sorry, I forgot to copy SRCCOPY across.
Const SRCCOPY As Integer = &HCC0020

BitBlt is part of the WinApi, specifically the GDI dll.
This is shown by the declaration:
Public Declare Function BitBlt Lib "gdi32" ( ...) As Integer
The Declare part tells the compiler that there's going to be mention of a function BitBlt but that the code isn't going to be given at this time. The Lib "gdi32" part tells it to find the actual routine externally.

Try this.
Dim x As New Bitmap 'Just to say that you want a BitMap
x = CaptureControl( Me)
x.Save ("zzz.bmp", Imaging.ImageFo rmat.Bmp)

Regards,
Fergus

[Herfried K. Wagner [MVP]]

"VB Programmer" <gr*********@ go-intech.com> scripsit:

Details: I have a form with a speedometer control on it. It continually
loops through a table in a db that has different current "speeds". I want
to "set" the speedometer to the current speed, then save the form as a
picture, then go to the next one, etc... The end result would be a gif or
jpeg that has a "snapshot" of the gauge. (This would eventually show up on
a aspx webform in an image control.)

<http://www.mvps.org/dotnet/dotnet/samples/windowsandforms/downloads/Screenshot.zip>

--
Herfried K. Wagner
MVP · VB Classic, VB.NET
<http://www.mvps.org/dotnet>

[Herfried K. Wagner [MVP]]

"Fergus Cooney" <fi******@tesco .net> scripsit:

function BitBlt but that the code isn't going to be given at this time. The
Lib "gdi32" part tells it to find the actual routine externally.

Try this.
Dim x As New Bitmap 'Just to say that you want a BitMap
I still don't understand why you declare 'x' as 'New Bitmap'.
x = CaptureControl( Me)
x.Save ("zzz.bmp", Imaging.ImageFo rmat.Bmp)

--
Herfried K. Wagner
MVP · VB Classic, VB.NET
<http://www.mvps.org/dotnet>

[VB Programmer]

Thank you. I appreciate your help.

"Herfried K. Wagner [MVP]" <hi************ ***@gmx.at> wrote in message
news:bm******** ****@ID-208219.news.uni-berlin.de...

"VB Programmer" <gr*********@ go-intech.com> scripsit:

Details: I have a form with a speedometer control on it. It continually loops through a table in a db that has different current "speeds". I want to "set" the speedometer to the current speed, then save the form as a
picture, then go to the next one, etc... The end result would be a gif or jpeg that has a "snapshot" of the gauge. (This would eventually show up on a aspx webform in an image control.)

<http://www.mvps.org/dotnet/dotnet/sa...nloads/Screens
hot.zip>
--
Herfried K. Wagner
MVP · VB Classic, VB.NET
<http://www.mvps.org/dotnet>