python - 为什么我的 wxpython 程序在关闭时崩溃了？

Question

我被难住了 - 希望另一双眼睛能够看到我在这里错过的东西。

我创建了一个 wxpython 程序(Windows 8.1 上的 Python 2.7.5 下的 wxpython 2.8.12.1)。该程序的一部分是我创建的自定义控件，用于为用户表单生成透明的箭头形按钮。

当我在表单中包含按钮时，它们的工作方式和外观完全符合预期；但是当我关闭顶层窗口时，程序崩溃了。我在 Visual Studio 中打开它，它告诉我堆已损坏，并表示问题出在 ntdll.dll 中。确切的错误消息如下:

Unhandled exception at 0x00007FFC5FE912E0 (ntdll.dll) in python.exe: 0xC0000374: A heap has been corrupted (parameters: 0x00007FFC5FECDD40).

我已经尝试禁用部分代码，但我似乎无法追踪问题，并且我无法在 Eclipse 调试器中遍历它(它似乎发生在我的任何类获得 wx 之前) .EVT_CLOSE 事件)。如果程序中包含我的任何箭头，则崩溃始终会发生，否则不会发生。我怀疑这与我使用 DC 来绘制控件有关(我以前很少使用它们)，但这只不过是一个 SWAG，我真的不知道我做错了什么。

任何见解都会受到赞赏 - 我希望这是一些我看不到的非常明显的东西。

该控件的代码如下(有点长，抱歉):

# ArrowButton.py
#
# Class module for ArrowButton control.
#
# Creates a button shaped like an arrow, pointing up (AB_STYLE_UPARROW, default) or down (AB_STYLE_DOWNARROW).
#
# This object generates wx.EVT_BUTTON events when clicked.
#
import wx

AB_STYLE_UPARROW = 256
AB_STYLE_DOWNARROW = 512

AB_MIN_WIDTH = 20
AB_MIN_HEIGHT = 12

AB_ACTIVE = 0
AB_DISABLED = 1
AB_PRESSED = 2
AB_PRESSED_OUTSIDE = 3

ROOT3 = 1.7320508075

class ArrowButton(wx.Control):
    def __init__(self, parent, id = wx.ID_ANY, pos = wx.DefaultPosition, size = wx.DefaultSize,
                 style = AB_STYLE_UPARROW, validator = wx.DefaultValidator, name = "ArrowButton"):

        self.__style__ = style & (AB_STYLE_UPARROW + AB_STYLE_DOWNARROW)
        if not (self.__style__ & AB_STYLE_UPARROW or self.__style__ & AB_STYLE_DOWNARROW):
            raise ValueError("{} __init__ must specify AB_STYLE_UPARROW or AB_STYLE_DOWNARROW as one of its flags.".format(self.__class__.__name__))

        if size == wx.DefaultSize:
            calcsize = (AB_MIN_WIDTH, AB_MIN_HEIGHT)
        else:
            calcsize = size

        wx.Control.__init__(self, parent = parent, id = id, pos = pos, size = calcsize, 
                            style = (style & ~(AB_STYLE_UPARROW + AB_STYLE_DOWNARROW) | wx.TRANSPARENT_WINDOW | wx.NO_BORDER), 
                            validator = validator, name = name)

        self.SetSize(calcsize)
        self.SetSizeHints(*calcsize)
        self.SetMinSize(calcsize)

        self.__activebitmap__ = None
        self.__greyedbitmap__ = None
        self.__pressedbitmap__ = None
        self.__sensitivity__ = None

        self.__mode__ = AB_ACTIVE

        self.Bind(wx.EVT_LEFT_DOWN, self.__OnMouse__)
        self.Bind(wx.EVT_LEFT_DCLICK, self.__OnMouse__)
        self.Bind(wx.EVT_SIZE, self.__OnSize__)
        self.Bind(wx.EVT_ERASE_BACKGROUND, lambda event: None)
        self.Bind(wx.EVT_PAINT, self.__OnPaint__)

        self.__GenerateBitmaps__()

    def __GenerateBitmaps__(self):
        size = self.GetClientSizeTuple()

        Color = wx.SystemSettings.GetColour  # This is a helper to shorten the text below.
        bcFace = Color(wx.SYS_COLOUR_3DFACE)
        bcLEdge = Color(wx.SYS_COLOUR_3DLIGHT)
        bcDEdge = Color(wx.SYS_COLOUR_3DSHADOW)

        self.__activebitmap__ = wx.EmptyBitmap(size[0], size[1])
        self.__greyedbitmap__ = wx.EmptyBitmap(size[0], size[1])
        self.__pressedbitmap__ = wx.EmptyBitmap(size[0], size[1])
        self.__sensitivity__ = wx.EmptyBitmap(size[0], size[1])

        memdc = wx.MemoryDC()

        maskbitmap = wx.EmptyBitmap(size[0], size[1], depth = 1)
        memdc.SelectObject(maskbitmap)
        memdc.SetBackground(wx.WHITE_BRUSH)
        memdc.Clear()
        self.__GenerateTriangle__(memdc, (0, 0, size[0], size[1]), wx.BLACK, wx.BLACK, wx.BLACK)
        memdc.SelectObject(wx.NullBitmap)
        mask = wx.Mask(maskbitmap)

        memdc.SelectObject(self.__sensitivity__)
        self.__GenerateTriangle__(memdc, (0, 0, size[0], size[1]), wx.RED, wx.RED, None)

        memdc.SelectObject(self.__activebitmap__)
        self.__GenerateTriangle__(memdc, (0, 0, size[0], size[1]), bcFace, bcLEdge, bcDEdge)

        memdc.SelectObject(self.__greyedbitmap__)
        self.__GenerateTriangle__(memdc, (0, 0, size[0], size[1]), bcFace, bcLEdge, None)

        memdc.SelectObject(self.__pressedbitmap__)
        self.__GenerateTriangle__(memdc, (0, 0, size[0], size[1]), bcFace, bcDEdge, bcLEdge)

        memdc.SelectObject(wx.NullBitmap)
        self.__activebitmap__.SetMask(mask)
        self.__greyedbitmap__.SetMask(mask)
        self.__pressedbitmap__.SetMask(mask)



    def __GenerateTriangle__(self, dc, where, face, bright, shadow):
        if where[2] > ((2 * where[3]) / ROOT3):  # The box is wider than it needs to be.
            top = where[1]
            bottom = where[1] + where[3] - 1
            left = (where[0] + (where[2] / 2)) - int(where[3] / ROOT3)
            right = (where[0] + (where[2] / 2)) + int(where[3] / ROOT3)
        else:  # The box is taller than it needs to be.
            left = where[0]
            right = where[0] + where[2] - 1
            top = (where[1] + (where[3] / 2)) - int((where[2] * ROOT3) / 4)
            bottom = (where[1] + (where[3] / 2)) + int((where[2] * ROOT3) / 4)

        dc.SetBrush(wx.Brush(face, wx.SOLID))
        dc.SetPen(wx.Pen(bright, 1, wx.SOLID))
        if self.__style__ & AB_STYLE_UPARROW:
            dc.DrawPolygon(points = [((left + right) / 2, top), (right, bottom), (left, bottom)])
            if shadow:
                dc.SetPen(wx.Pen(shadow, 1, wx.SOLID))
                dc.DrawLine(left, bottom, right, bottom)
                dc.DrawLine(right, bottom, (left + right) / 2, top)
        else:
            dc.DrawPolygon(points = [((left + right) / 2, bottom), (right, top), (left, top)])
            if shadow:
                dc.SetPen(wx.Pen(shadow, 1, wx.SOLID))
                dc.DrawLine((left + right) / 2, bottom, right, top)

    def DoGetBestSize(self):
        return ((AB_MIN_WIDTH, AB_MIN_HEIGHT))

    def Disable(self):
        if self.__mode__ == AB_PRESSED or self.__mode__ == AB_PRESSED_OUTSIDE:
            self.Unbind(wx.EVT_MOTION, self.__OnMouse__)
            self.Unbind(wx.EVT_LEFT_UP, self.__OnMouse__)
        elif self.__mode__ == AB_ACTIVE:
            self.Unbind(wx.EVT_LEFT_DOWN)
            self.Unbind(wx.EVT_LEFT_DCLICK)

        self.__mode__ = AB_DISABLED
        self.Refresh()

        return wx.Control.Disable(self)

    def Enable(self, enable = True):
        if not enable:
            return self.Disable()

        self.Bind(wx.EVT_LEFT_DOWN, self.__OnMouse__)
        self.Bind(wx.EVT_LEFT_DCLICK, self.__OnMouse__)
        self.__mode__ = AB_ACTIVE
        self.Refresh()

        return wx.Control.Enable(self, enable = enable)

    def __OnMouse__(self, event):
        if self.__mode__ == AB_DISABLED:
            event.Skip()
            return

        where = event.GetPositionTuple()
        memdc = wx.MemoryDC()
        memdc.SelectObject(self.__sensitivity__)
        inbounds = (memdc.GetPixel(*where).Get()[0] <> 0)

        if self.__mode__ == AB_PRESSED:
            if event.LeftUp():  # The button was released.
                self.__mode__ = AB_ACTIVE
                self.Refresh()

                self.Unbind(wx.EVT_MOTION)
                self.Unbind(wx.EVT_LEFT_UP)
                self.Unbind(wx.EVT_MOUSE_CAPTURE_LOST)
                self.Bind(wx.EVT_LEFT_DOWN, self.__OnMouse__)
                self.Bind(wx.EVT_LEFT_DCLICK, self.__OnMouse__)

                self.ReleaseMouse()

                newevent = wx.CommandEvent(commandType = wx.EVT_BUTTON.evtType[0], winid = self.GetId())
                newevent.SetEventObject(self)
                wx.PostEvent(self, newevent)
                return

            elif event.Dragging():
                if not inbounds:
                    self.__mode__ = AB_PRESSED_OUTSIDE
                    self.Refresh()

        elif self.__mode__ == AB_PRESSED_OUTSIDE:
            if event.LeftUp():
                self.__mode__ = AB_ACTIVE
                self.Refresh()

                self.Unbind(wx.EVT_MOTION)
                self.Unbind(wx.EVT_LEFT_UP)
                self.Unbind(wx.EVT_MOUSE_CAPTURE_LOST)
                self.Bind(wx.EVT_LEFT_DOWN, self.__OnMouse__)
                self.Bind(wx.EVT_LEFT_DCLICK, self.__OnMouse__)

                self.ReleaseMouse()

            elif event.Dragging():
                if inbounds:
                    self.__mode__ = AB_PRESSED
                    self.Refresh()

        else:  # Assume the button is in ACTIVE
            if event.LeftDown() | event.LeftDClick():
                if inbounds:
                    self.__mode__ = AB_PRESSED
                    self.Refresh()

                    self.Unbind(wx.EVT_LEFT_DOWN)
                    self.Unbind(wx.EVT_LEFT_DCLICK)
                    self.Bind(wx.EVT_LEFT_UP, self.__OnMouse__)
                    self.Bind(wx.EVT_MOTION, self.__OnMouse__)
                    self.Bind(wx.EVT_MOUSE_CAPTURE_LOST, self.__OnMouseCaptureLost__)

                    self.CaptureMouse()

                    return

        event.Skip()

    def __OnMouseCaptureLost__(self, event):
        if self.__mode__ == AB_PRESSED or self.__mode__ == AB_PRESSED_OUTSIDE:
            self.__mode__ = AB_ACTIVE

            self.Unbind(wx.EVT_MOTION)
            self.Unbind(wx.EVT_LEFT_UP)
            self.Unbind(wx.EVT_MOUSE_CAPTURE_LOST)
            self.Bind(wx.EVT_LEFT_DOWN, self.__OnMouse__)
            self.Bind(wx.EVT_LEFT_DCLICK, self.__OnMouse__)

            self.Refresh()


    def __OnSize__(self, event):
        size = event.GetSize()
        if size[0] < AB_MIN_WIDTH:
            size[0] = AB_MIN_WIDTH
        if size[1] < AB_MIN_HEIGHT:
            size[1] = AB_MIN_HEIGHT
        event.Skip()

        self.__GenerateBitmaps__()

    def __OnPaint__(self, event):
        dc = wx.PaintDC(self)
        if self.__mode__ == AB_DISABLED:
            dc.DrawBitmap(self.__greyedbitmap__, 0, 0, True)
        elif self.__mode__ == AB_PRESSED:
            dc.DrawBitmap(self.__pressedbitmap__, 0, 0, True)
        else:  # The button is ACTIVE or PRESSED_OUTSIDE.
            dc.DrawBitmap(self.__activebitmap__, 0, 0, True)

Answer 1

我知道问题出在哪里了。

问题是我对多个位图使用了一个 wx.Mask 对象；我的猜测是，崩溃是由于程序关闭时多次尝试释放掩码而导致的。

解决方案是为每个位图创建一个掩码。我认为这是浪费资源，因为蒙版都是相同的 - 但另一方面，每个蒙版通常都是 20x12 单色位图(我偶尔会陷入 20 世纪 80 年代末的编码思维模式)。

以下是受影响部分的修改后的代码:

def __GenerateBitmaps__(self):
    size = self.GetClientSizeTuple()

    Color = wx.SystemSettings.GetColour  # This is a helper to shorten the text below.
    bcFace = Color(wx.SYS_COLOUR_3DFACE)
    bcLEdge = Color(wx.SYS_COLOUR_3DLIGHT)
    bcDEdge = Color(wx.SYS_COLOUR_3DSHADOW)

    self.__activebitmap__ = wx.EmptyBitmap(size[0], size[1])
    self.__greyedbitmap__ = wx.EmptyBitmap(size[0], size[1])
    self.__pressedbitmap__ = wx.EmptyBitmap(size[0], size[1])
    self.__sensitivity__ = wx.EmptyBitmap(size[0], size[1])

    memdc = wx.MemoryDC()

    maskbitmap = wx.EmptyBitmap(size[0], size[1], depth = 1)
    memdc.SelectObject(maskbitmap)
    memdc.SetBackground(wx.WHITE_BRUSH)
    memdc.Clear()
    self.__GenerateTriangle__(memdc, (0, 0, size[0], size[1]), wx.BLACK, wx.BLACK, wx.BLACK)
    memdc.SelectObject(wx.NullBitmap)
    abmmask = wx.Mask(maskbitmap)   # <--- 
    gbmmask = wx.Mask(maskbitmap)   # <--- New code to make multiple masks.
    pbmmask = wx.Mask(maskbitmap)   # <---

    memdc.SelectObject(self.__sensitivity__)
    self.__GenerateTriangle__(memdc, (0, 0, size[0], size[1]), wx.RED, wx.RED, None)

    memdc.SelectObject(self.__activebitmap__)
    self.__GenerateTriangle__(memdc, (0, 0, size[0], size[1]), bcFace, bcLEdge, bcDEdge)

    memdc.SelectObject(self.__greyedbitmap__)
    self.__GenerateTriangle__(memdc, (0, 0, size[0], size[1]), bcFace, bcLEdge, None)

    memdc.SelectObject(self.__pressedbitmap__)
    self.__GenerateTriangle__(memdc, (0, 0, size[0], size[1]), bcFace, bcDEdge, bcLEdge)

    memdc.SelectObject(wx.NullBitmap)
    self.__activebitmap__.SetMask(abmmask)  # <---
    self.__greyedbitmap__.SetMask(gbmmask)  # <--- Code edited to apply new masks.
    self.__pressedbitmap__.SetMask(pbmmask) # <---