Screen Capture - VB.NET

I've made a small tutorial on how to make a ScreenCap Application

You need:
- A button



Start a new project and add this under "Public Class Form1"

Code:

Inherits System.Windows.Forms.Form

    Private Declare Function CreateDC Lib "gdi32" Alias "CreateDCA" (ByVal lpDriverName As String, ByVal lpDeviceName As String, ByVal lpOutput As String, ByVal lpInitData As String) As Integer

    Private Declare Function CreateCompatibleDC Lib "GDI32" (ByVal hDC As Integer) As Integer

    Private Declare Function CreateCompatibleBitmap Lib "GDI32" (ByVal hDC As Integer, ByVal nWidth As Integer, ByVal nHeight As Integer) As Integer

    Private Declare Function GetDeviceCaps Lib "gdi32" Alias "GetDeviceCaps" (ByVal hdc As Integer, ByVal nIndex As Integer) As Integer

    Private Declare Function SelectObject Lib "GDI32" (ByVal hDC As Integer, ByVal hObject As Integer) As Integer

    Private Declare Function BitBlt Lib "GDI32" (ByVal srchDC As Integer, ByVal srcX As Integer, ByVal srcY As Integer, ByVal srcW As Integer, ByVal srcH As Integer, ByVal desthDC As Integer, ByVal destX As Integer, ByVal destY As Integer, ByVal op As Integer) As Integer

    Private Declare Function DeleteDC Lib "GDI32" (ByVal hDC As Integer) As Integer

    Private Declare Function DeleteObject Lib "GDI32" (ByVal hObj As Integer) As Integer

    Const SRCCOPY As Integer = &HCC0020

    Private oBackground As Bitmap
    Private FW, FH As Integer

Now add this sub anywhere to your project, just make sure it's not in another sub.

Code:

Protected Sub CaptureScreen()

        Dim hSDC, hMDC As Integer
        Dim hBMP, hBMPOld As Integer
        Dim r As Integer

        hSDC = CreateDC("DISPLAY", "", "", "")
        hMDC = CreateCompatibleDC(hSDC)

        FW = GetDeviceCaps(hSDC, 8)
        FH = GetDeviceCaps(hSDC, 10)
        hBMP = CreateCompatibleBitmap(hSDC, FW, FH)

        hBMPOld = SelectObject(hMDC, hBMP)
        r = BitBlt(hMDC, 0, 0, FW, FH, hSDC, 0, 0, 13369376)
        hBMP = SelectObject(hMDC, hBMPOld)

        r = DeleteDC(hSDC)
        r = DeleteDC(hMDC)

        oBackground = Image.FromHbitmap(New IntPtr(hBMP))
        DeleteObject(hBMP)

    End Sub

And if you want Button1 to capture the screen and save it to C:/picture.jpg you would do this

Code:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        CaptureScreen()
        oBackground.save("C:/picture.jpg")
    End Sub

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