お手数うですが教えてください。
Public Class Form1
<System.Runtime.InteropServices.DllImport("USER32.DLL")> _
Private Declare Function GetPixel Lib "gdi32" Alias "GetPixel" _
(ByVal hdc As Long, ByVal nXPos As Long, ByVal nYPos As Long) As Long
Declare Function FindWindow Lib "User32.dll" Alias "FindWindowA" _
(ByVal lpClassName As String, _
ByVal lpWindowName As String) As Long
Dim whl As Long
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
whl = FindWindow("", "MyAppli")
'TextBox1.Text = whl.ToString()
Dim color As Long
color = Form1.GetPixel(whl, 100, 200)
TextBox1.Text = color.ToString()
End Sub
End Class
以下のような感じではないでしょうか。
デバッグはしておりません。
Dim c As Color = Form1.GetPixel(whl, 100, 200) TextBox1.Text = c.ToArgb()
http://msdn.microsoft.com/ja-jp/library/system.drawing.color.toargb.aspx#Y0
http://msdn.microsoft.com/ja-jp/library/system.drawing.bitmap.getpixel(v=vs.80).aspx#Y555