wxPython 菜单不显示图像 [英] wxPython menu doesn't display image

问题描述

我正在创建一个菜单并将图像分配给菜单项，有时菜单中的第一项不显示任何图像，我找不到原因.我试图制作一个简单的独立示例，下面是在我的机器上演示问题的代码.我使用的是 Windows XP，wx 2.8.7.1 (msw-unicode)'

I am creating a menu and assigning images to menu items, sometime first item in menu doesn't display any image, I am not able to find the reason. I have tried to make a simple stand alone example and below is the code which does demonstrates the problem on my machine. I am using windows XP, wx 2.8.7.1 (msw-unicode)'

import wx

def getBmp():
    bmp = wx.EmptyBitmap(16,16)
    return bmp

class MyFrame(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, style=wx.DEFAULT_FRAME_STYLE, parent=None)

        self.SetTitle("why New has no image?")

        menuBar = wx.MenuBar()
        fileMenu=wx.Menu()
        item = fileMenu.Append(wx.ID_NEW, "New")
        item.SetBitmap(getBmp())
        item = fileMenu.Append(wx.ID_OPEN, "Open")
        item.SetBitmap(getBmp())
        item = fileMenu.Append(wx.ID_SAVE, "Save")
        item.SetBitmap(getBmp())
        menuBar.Append(fileMenu, "File")
        self.SetMenuBar(menuBar) 


app = wx.PySimpleApp()
frame=MyFrame()
frame.Show()
app.SetTopWindow(frame)
app.MainLoop()

那么您是否能够看到问题以及可能的原因是什么?

So are you able to see the problem and what could be the reason for it?

结论:是的，这是一个官方错误，我创建了一个简单的 Menu 类来克服这个错误，使用所选答案中balpha"给出的技巧

Conclusion: Yes this is a official bug, I have created a simple Menu class to overcome this bug, using the trick given by "balpha" in selected answer

它会覆盖每个 menu.Append 方法，并查看是否是第一次添加带有图像的菜单项，如果是，则创建一个虚拟项并稍后将其删除.

It overrides each menu.Append method and sees if menu item with image is being added for first time, if yes creates a dummy item and deletes it later.

这也增加了特性/约束，因此您应该将位图作为可选参数图像传递，而不是调用 SetBitmap

This also adds feature/constraint so that instead of calling SetBitmap, you should pass bitmap as optional argument image

import wx

class MockMenu(wx.Menu):
    """
    A custom menu class in which image param can be passed to each Append method
    it also takes care of bug http://trac.wxwidgets.org/ticket/4011
    """

    def __init__(self, *args, **kwargs):
        wx.Menu.__init__(self, *args, **kwargs)
        self._count = 0

    def applyBmp(self, unboundMethod, *args, **kwargs):
        """
        there is a bug in wxPython so that it will not display first item bitmap
        http://trac.wxwidgets.org/ticket/4011
        so we keep track and add a dummy before it and delete it after words
        may not work if menu has only one item
        """

        bmp = None
        if 'image' in kwargs:
            bmp = kwargs['image']

        tempitem = None
        # add temp item so it is first item with bmp 
        if bmp and self._count == 1:
            tempitem = wx.Menu.Append(self, -1,"HACK")
            tempitem.SetBitmap(bmp)

        ret = unboundMethod(self, *args, **kwargs)
        if bmp:
            ret.SetBitmap(bmp)

        # delete temp item
        if tempitem is not None:
            self.Remove(tempitem.GetId())

        self._lastRet = ret
        return ret

    def Append(self, *args, **kwargs):
        return self.applyBmp(wx.Menu.Append, *args, **kwargs)

    def AppendCheckItem(self, *args, **kwargs):
        return self.applyBmp(wx.Menu.AppendCheckItem, *args, **kwargs)

    def AppendMenu(self, *args, **kwargs):
        return self.applyBmp(wx.Menu.AppendMenu, *args, **kwargs)

推荐答案

这是一个 已确认的错误 似乎已经开放了一段时间.在尝试了一点之后，这个解决方法似乎可以做到:

This is a confirmed bug which appearently has been open for quite a while. After trying around a little bit, this workaround seems to do it:

    menuBar = wx.MenuBar()
    fileMenu=wx.Menu()
    tempitem = fileMenu.Append(-1,"X")       # !!!
    tempitem.SetBitmap(getBmp())             # !!!
    item = fileMenu.Append(wx.ID_NEW, "New")
    fileMenu.Remove(tempitem.GetId())        # !!!
    item.SetBitmap(getBmp())
    item = fileMenu.Append(wx.ID_OPEN, "Open")
    item.SetBitmap(getBmp())
    item = fileMenu.Append(wx.ID_SAVE, "Save")
    item.SetBitmap(getBmp())
    menuBar.Append(fileMenu, "File")
    self.SetMenuBar(menuBar) 

注意，fileMenu.Remove 调用的位置是最早起作用的位置，但您也可以将其移动到底部.哈.

Note that the position of the fileMenu.Remove call is the earliest position that works, but you can also move it to the bottom. HTH.

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