wxWidgets的Pen Style

Window编程中，有所谓的Pen Style，能让画出的线呈现不同的形式，如由点形成的线、有短划线形成的线等。

下面的是从pen.h萃取出来的这些Pen Style：

enum wxPenStyle
{
    wxPENSTYLE_INVALID = -1,

    wxPENSTYLE_SOLID = wxSOLID,
    wxPENSTYLE_DOT = wxDOT,
    wxPENSTYLE_LONG_DASH = wxLONG_DASH,
    wxPENSTYLE_SHORT_DASH = wxSHORT_DASH,
    wxPENSTYLE_DOT_DASH = wxDOT_DASH,
    wxPENSTYLE_USER_DASH = wxUSER_DASH,

    wxPENSTYLE_TRANSPARENT = wxTRANSPARENT,

    wxPENSTYLE_STIPPLE_MASK_OPAQUE = wxSTIPPLE_MASK_OPAQUE,
    wxPENSTYLE_STIPPLE_MASK = wxSTIPPLE_MASK,
    wxPENSTYLE_STIPPLE = wxSTIPPLE,

    wxPENSTYLE_BDIAGONAL_HATCH = wxHATCHSTYLE_BDIAGONAL,
    wxPENSTYLE_CROSSDIAG_HATCH = wxHATCHSTYLE_CROSSDIAG,
    wxPENSTYLE_FDIAGONAL_HATCH = wxHATCHSTYLE_FDIAGONAL,
    wxPENSTYLE_CROSS_HATCH = wxHATCHSTYLE_CROSS,
    wxPENSTYLE_HORIZONTAL_HATCH = wxHATCHSTYLE_HORIZONTAL,
    wxPENSTYLE_VERTICAL_HATCH = wxHATCHSTYLE_VERTICAL,
    wxPENSTYLE_FIRST_HATCH = wxHATCHSTYLE_FIRST,
    wxPENSTYLE_LAST_HATCH = wxHATCHSTYLE_LAST
};

这些PenStyle，可以通过下面类似的方式，在调用DC的绘制函数前设置：

wxPen pen(wxColor(255, 0, 0), 1, wxPENSTYLE_DOT);

然后，用

dc.SetPen(pen);

把DC当前的Pen换成自己的。自此，绘制线的时候，都会用上刚才设置的笔。