Dropper color tool

[mattscotney]

How do I create an color dropper tool?

 

I need the code to get the color of the pixel at the position of the mouse.

 

This is what I have done so far, I can get the pixel color of a bitmap, but how do I get the color of the screen at any given pixel?

Dim bmp = New Bitmap("bg.gif")
Dim z As Color

z = bmp.GetPixel(50, 50)
MsgBox(z.ToString)

Label4.BackColor = z

 

Thanks in advance

Edited July 10, 2003 by mattscotney

[ballisticnylon]

Do you mean anywhere in the client area, or anywhere on the whole screen? Because receiving mouse events from outside is a bit tricky, and requires API calls, I think.

[mattscotney]

Anywhere on the whole screen. Doing it for the client area would be a start though.

[divil]

   Private Declare Function GetPixel Lib "gdi32" Alias "GetPixel" (ByVal hdc As IntPtr, ByVal x As Integer, ByVal y As Integer) As Integer
   Private Declare Function GetDC Lib "user32" Alias "GetDC" (ByVal hwnd As IntPtr) As IntPtr
   Private Declare Function ReleaseDC Lib "user32" Alias "ReleaseDC" (ByVal hwnd As IntPtr, ByVal hdc As IntPtr) As Integer

   Private Sub Panel1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Panel1.MouseMove
       Dim hdc As IntPtr = GetDC(IntPtr.Zero)
       Dim p As Point = Panel1.PointToScreen(New Point(e.X, e.Y))
       Dim c As Integer = GetPixel(hdc, p.X, p.Y)

       Dim color As Color = ColorTranslator.FromOle(c)
       ReleaseDC(IntPtr.Zero, hdc)

       Panel1.BackColor = color
   End Sub

 

That'll do it. Click on the panel and you can drag over the whole screen, the panel's background colour will change as you move over different coloured pixels.