Screenshot? How?? [Resolved]

[Libero]

I have searched through a tons of forums and other sites, but i cannot find any good code to make a screenshot and then save it as a *.jpg file. I know you can convert *.bmp to other formats quite easally with .net. Please, point me in the right direction!

[Libero]

Noone answered so i solved it myself. For you that is interested how, here is my code:

Private Declare Sub keybd_event Lib "user32" (ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As Integer, ByVal dwExtraInfo As Integer)
    Private Const VK_SNAPSHOT As Short = &H2Cs
 
 
Public Function SaveScreen()
        Call keybd_event(System.Windows.Forms.Keys.Snapshot, 0, 0, 0)
        Dim iData As IDataObject = Clipboard.GetDataObject()
        PictureBox1.Image = iData.GetData(DataFormats.Bitmap)
        PictureBox1.Image.Save("c:\test.jpg")
    End Function

Test it, works like a acharm...

[Libero]

Correction:

Call keybd_event(System.Windows.Forms.Keys.Snapshot, 0, 0, 0)

Change to

Call keybd_event(System.Windows.Forms.Keys.Snapshot, 1, 0, 0)

[BukHix]

Very Cool. Thanks.

[LITHIA]

u sure that saves as jpg? It looks like its saving as a bitmap to me with a false file extentsion...
check the file size and check if its bmp or jpg, because i dont see anything (other than the filename) that could indicate any conversation from bitmap to jpeg. would be interesting to know.

edit:

PictureBox1.Image = iData.GetData(DataFormats.Bitmap)

i may sound dumb, but seriously, that has to be a bitmap being saved here

[BukHix]

LITHIA I think you are right about that. When I opened the image with iFranView it claimed it was a png file with the wrong extension.

[wey97]

It's working on my system...a 1024X768 bitmap is 2.25 MB!

The test.jpg is only 52.7 KB and opens up fine as a JPG.

[Libero]

wey97 is correct. The size depends on if you got alot of color or not in your screenshot. Lets say that you take a screenie with this forum open ( maxixmized ) then you got got a much much smaller bitmap the if you take a screenie where you got a lot of colors...

[Libero]

Stupid stupid me LITHIA was right, "It looks like its saving as a bitmap to me with a false file extentsion". I have worked on a real solution and came up with this:

Private Declare Sub keybd_event Lib "user32" (ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As Integer, ByVal dwExtraInfo As Integer)
    Private Const VK_SNAPSHOT As Short = &H2CS
    
    
    Public Function SaveScreen(ByVal theFile As String) As Boolean
        Dim data As IDataObject
        data = Clipboard.GetDataObject()
        Dim bmap As Bitmap
        If data.GetDataPresent(GetType(System.Drawing.Bitmap)) Then
            bmap = CType(data.GetData(GetType(System.Drawing.Bitmap)), Bitmap)
            Me.PictureBox1.Image = bmap
            Me.PictureBox1.Image.Save(theFile)
            ConvertImage(theFile, System.Drawing.Imaging.ImageFormat.Jpeg, "c:\img.jpg")
        End If
    End Function
 
    Public Sub ConvertImage(ByVal Filename As String, _
      ByVal DesiredFormat As System.Drawing.Imaging.ImageFormat, _
      ByVal NewFilename As String)
        Try
            Dim imgFile As System.Drawing.Image = _
              System.Drawing.Image.FromFile(Filename)
            imgFile.Save(NewFilename, DesiredFormat)
        Catch ex As Exception
            Throw ex
        End Try
    End Sub

Filesize before converted = 884Kb
Filesize after converted = 146Kb

This rocks!!

[Libero]

This was even better:

Private Declare Sub keybd_event Lib "user32" (ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As Integer, ByVal dwExtraInfo As Integer)
    Private Const VK_SNAPSHOT As Short = &H2Cs
    
    
    Public Function SaveScreen(ByVal theFile As String) As Boolean
        Dim data As IDataObject
        data = Clipboard.GetDataObject()
        Dim bmap As Bitmap
        If data.GetDataPresent(GetType(System.Drawing.Bitmap)) Then
            bmap = CType(data.GetData(GetType(System.Drawing.Bitmap)), Bitmap)
            Me.PictureBox1.Image = bmap
            Me.PictureBox1.Image.Save(theFile, Imaging.ImageFormat.Jpeg)
        End If
    End Function
 
    Private Sub Command2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Command2.Click
        Call keybd_event(System.Windows.Forms.Keys.Snapshot, 0, 0, 0)
        System.Threading.Thread.Sleep(200) ' To have time to catch the clipboard
        SaveScreen("c:\test.jpg")
    End Sub

[LITHIA]

nice, i had a problem like this in VB6 - had no idea how to convert to jpeg, looks a lot easier with .NET tho, thank goodness lol.

good work

[Libero]

Thx! LITHIA> You´re right. I have fiddled around about one and a half week with VB.NET now, and damn its so much more powerful than VB6. Ooohhh! Im in love with .NET

[dinosaur_uk]

Wow ...cool

thanks for this thread.

Two Questions:

1. Must you have an picturebox in order for this to work?
2. Can we adapt this so that it can only capture the form which called it?

Cheers!

[NoteMe]

If you send the ALT key at the same time, you will only get the form that is in Focus.


ØØ

[wossname]

This is fully using managed framework code...

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 
        If Not SaveScreen(Application.StartupPath & "\screen.jpg") Then
            MessageBox.Show("Sorry dude, couldn't do it.")
        End If
 
    End Sub
 
    Public Function SaveScreen(ByVal theFile As String) As Boolean
 
        Try
            SendKeys.Send("%{PRTSC}")            '<alt + printscreen>
            Application.DoEvents()
 
            Dim data As IDataObject
            data = Clipboard.GetDataObject()
            Dim bmp As Bitmap
            If data.GetDataPresent(GetType(System.Drawing.Bitmap)) Then
                bmp = CType(data.GetData(GetType(System.Drawing.Bitmap)), Bitmap)
                bmp.Save(theFile, Imaging.ImageFormat.Jpeg)
            End If
            Clipboard.SetDataObject(0)        'save memory by removing the image from the clipboard
            Return True
        Catch ex As Exception
            Return False
        End Try
 
    End Function

[dinosaur_uk]

Sorry to dig up an old thread, but is it possible to get a screenshot of a MDI Child form? instead of the whole form?

[wossname]

I posted a thread about Blitting in the codebank a few months ago, the class therein contains a screengrab() function that you can pass the rectangle of yuor form into.