Windows 7上的CreatePen GDI函數問題

Question

當筆寬度爲3或4時（LineTo不繪製任何內容），CreatePen GDI函數在Windows 7上不起作用。它適用於0 - 2寬度。在所有情況下都使用PS_SOLID筆樣式。

Answer 1

LineTo不包括該行的最後一個點。嘗試一個不同的endcap設置，看看它是否有所作爲。

Answer 2

它是否返回一個句柄或NULL？
你有沒有考慮過使用CreatePenIndirect和結構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
這只是正常工作在我的電腦中，Windows 7 64位系統上：

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 

單擊按鈕多次