CreatePen GDI function problem on Windows 7
CreatePen GDI function does not work on Windows 7 when pen width开发者_如何转开发 is 3 or 4 (LineTo draws nothing). It works for 0 - 2 width. In all cases PS_SOLID pen style was used.
LineTo does not include the final point of the line. Try a different endcap setting to see if it makes a difference.
does it return a handle or NULL?
have you considered using CreatePenIndirect and the structure LOGPEN?
http://msdn.microsoft.com/en-us/library/dd183510(v=VS.85).aspx
http://msdn.microsoft.com/en-us/library/dd145041(v=VS.85).aspx
this just works fine on my computer, Windows 7 x64:
Option Explicit
Private Declare Function CreatePen Lib "gdi32" ( _
ByVal nPenStyle As Long, _
ByVal nWidth As Long, _
ByVal crColor As Long) As Long
Private Declare Function LineTo Lib "gdi32" ( _
ByVal hDC As Long, ByVal x As Long, ByVal y As Long) As Long
Private Declare Function SelectObject Lib "gdi32" ( _
ByVal hDC As Long, ByVal hObject As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" ( _
ByVal hObject As Long) As Long
Dim x As Long
Dim y As Long
Dim w As Long
Private Sub Command1_Click()
w = w + 1
Dim hpen As Long: hpen = CreatePen(0, w, 0)
Dim ret As Long: ret = SelectObject(Me.hDC, hpen)
If ret <> 0 Then
x = x + 10
y = y + 10
Call LineTo(Me.hDC, x, y)
End If
Call DeleteObject(hpen)
End Sub
click the button more times
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