Monitoring my desktop

[Static_Void]

Hello !
The last days I am wondering how to make screenshots of my pc every 5 minutes and then automatically put them in a zip folder. In C++ I read something about OpenGL, but could anyone tell me how to make this in VB (please don't tell me things like "try it with opengl" ^^) ? If it's possible to give me the source code, of course this would be the best (so i can learn of it). But if not, it's ok .

Thank you very much !
,Greetz Static_void

[Jim Davis]

how to make screenshots of my pc

You mean a screenshot of the desktop area? Use bitblt api, there are thousands of great examples of screenshot takers on psc, but i bet you can found them in here at the codebank also.

There is a ZipLib dll that you can use to zip the file, but there you may have to know the actual headers and structure of a .zip file that i dont know much about it. Google it. But if you just want to 'zip' one single file to make it smaller, the ziplib does the job as well..

http://www.zlib.net/ <- look for the (pre)compiled dll

Private Declare Function compress2 Lib "zlibwapi.dll" (dest As Any, destLen As Any, src As Any, ByVal srcLen As Long, ByVal Level As Integer) As Long
Private Declare Function uncompress Lib "zlibwapi.dll" (dest As Any, destLen As Any, src As Any, ByVal srcLen As Long) As Long

Function Zip(ByVal Container As String, ByRef origSize as long) As String
  Dim CmpSize As Long
  Dim TBuff As String
  Dim orgSize As Long
  Dim RES As Long
  
  orgSize = Len(Container)
  TBuff = String(orgSize + (orgSize * 0.01) + 12, 0)
  CmpSize = Len(TBuff)

  RES = compress2(ByVal TBuff, CmpSize, ByVal Container, Len(Container), 9)

  Zip = Left$(TBuff, CmpSize)
End Function 


Function UnZip(ByVal Container As String, ByVal origSize as Long) As String
  Dim CmpSize As Long
  Dim TBuff As String
  Dim RES As Long

  TBuff = String(origSize + (origSize * 0.01) + 12, 0)
  CmpSize = Len(TBuff)

  RES = uncompress(ByVal TBuff, CmpSize, ByVal Container, Len(Container))

  UnZip = Left$(TBuff, CmpSize)
End Function

Dont forget to store the origSize (that is the len of the string you wanna zip), because the unZip have to define the correct buffer size to unpack the packed material. you can simply store this size information at the start of your file, that is 4 byte long.

But i recommend you to convert the image to any common format, just like JPG or PNG. You can also downsample the size, and/or the bpp (bits per pixel) to make the image even smaller. Look around in the code banks for examples about image conversions. afaik by using gdiplus apis you can convert most of the image types. like gif/bmp/jpg/png/ and so on..

You can also do some comparing, that what areas of the screen are modified, so you only have to store the modified areas, but its not as simple as im talking about it...