如何在wxpython中使用Refresh和wx.ColourDialog？

Question

我正在尝试刷新（）使用 wx.ColourDialog 的面板。一旦我刷新面板一次，就无法再次刷新。请尝试执行以下操作来查看问题的实际情况。

单击该按钮，它会询问您要将矩形更改为什么颜色。一旦你按确定，它应该改变矩形的颜色。它不会工作，不会改变矩形。

import wx 
xcolor_of_font_dia=(0,0,0)
class MyFrame(wx.Frame): 
    """a frame with a panel"""
    def __init__(self, parent=None, id=wx.ID_ANY, title=None):
        global xcolor_of_font_dia
        global dc
        wx.Frame.__init__(self, parent, wx.ID_ANY, title) 
        self.panel = wx.Panel(self, size=(350, 200)) 
        self.panel.Bind(wx.EVT_PAINT, self.on_paint)
        self.button2 = wx.Button(self.panel, id=wx.ID_ANY, label='Button2',pos=(8, 38), size=(175, 28))
        self.button2.Bind(wx.EVT_BUTTON, self.onColorDlg)
        self.Fit() 
    def onColorDlg(self, event):
        global xcolor_of_font_dia
        global dc
        """
        This is mostly from the wxPython Demo!
        """
        dlg = wx.ColourDialog(self)

        # Ensure the full colour dialog is displayed, 
        # not the abbreviated version.
        dlg.GetColourData().SetChooseFull(True)

        if dlg.ShowModal() == wx.ID_OK:
            data = dlg.GetColourData()
            print 'You selected: %s\n' % str(data.GetColour().Get())
            xcolor_of_font_dia='#%02x%02x%02x' % data.GetColour().Get()
        dlg.Destroy()
        self.panel.Refresh()
    def on_paint(self, event):
        global xcolor_of_font_dia
        global dc
        dc = wx.PaintDC(self.panel)
        dc.SetPen(wx.Pen(xcolor_of_font_dia, 1))
        rect = wx.Rect(50, 50, 100, 100) 
        dc.DrawRoundedRectangleRect(rect, 8)


# test it ...
app = wx.PySimpleApp() 
frame1 = MyFrame(title='rounded-rectangle & circle') 
frame1.Center() 
frame1.Show() 
app.MainLoop()

Answer 1

我清理了一下你的代码。基本上，当您在每个大小事件后创建（和删除）不同的 dc 实例时，您的全局变量会产生一些问题。
如果不是绝对必要（很少是），则不应使用全局变量。

这有效：

import wx 


class MyFrame(wx.Frame): 
    """a frame with a panel"""
    def __init__(self, parent=None, id=wx.ID_ANY, title=None):
        wx.Frame.__init__(self, parent, wx.ID_ANY, title) 
        self.xcolor = (0, 0, 0)
        self.panel = wx.Panel(self, size=(350, 200)) 
        self.panel.Bind(wx.EVT_PAINT, self.on_paint)
        self.button2 = wx.Button(self.panel, id=wx.ID_ANY, label='Button2',
                                             pos=(8, 38), size=(175, 28))
        self.button2.Bind(wx.EVT_BUTTON, self.onColorDlg)

        self.Fit() 

    def onColorDlg(self, event):
        """
        This is mostly from the wxPython Demo!
        """
        dlg = wx.ColourDialog(None)
        dlg.GetColourData().SetChooseFull(True)

        if dlg.ShowModal() == wx.ID_OK:
            data = dlg.GetColourData()
            self.xcolor = data.GetColour().Get()
            print 'You selected: %s\n' % str(self.xcolor)

        dlg.Destroy()
        self.panel.Refresh()

    def on_paint(self, event):
        dc = wx.PaintDC(self.panel)
        dc.SetPen(wx.Pen(self.xcolor, 2))
        rect = wx.Rect(50, 50, 100, 100) 
        dc.DrawRoundedRectangleRect(rect, 8)


# test it ...
app = wx.PySimpleApp() 
frame1 = MyFrame(title='rounded-rectangle & circle') 
frame1.Center() 
frame1.Show() 
app.MainLoop()