图形故障 ttk 小部件

Question

这一切都始于一个正常的tk.Scale 没有被正确地担心（我使用的是自定义主题）。
然后我切换到ttk.Scale，但是当我更改它时它没有显示滑块上方的值。
然后我发现了 ttkwidget，它似乎可以工作，但有图形故障。有人有什么想法可以解决吗？
代码：https://pastebin.com/bxgvsjSF
截图：https://ibb.co/tLdjLrx
附言此外，有问题的小部件加载小部件非常慢

编辑：解决方案在最佳答案的评论中

Answer 1

我找到了消除ttk.LabeledScale 中的故障的方法。我认为问题在于重绘整个 Label 小部件，所以我改用了 Canvas。使用Canvas，当文字移动时，不需要重绘背景，动画更流畅。

以下代码基于ttk.LabeledScale的源代码（来自Python 3.9.1，您可以在tkinter/ttk.py中找到它）。但是小部件现在基于Canvas，其中添加了create_window() 和ćreate_text() 的比例和文本。我修改了__init__() 和_adjust() 方法，并添加了一个_on_theme_change() 方法，该方法在主题更改时调用以更新画布的样式并调整元素的位置。

import tkinter as tk
from tkinter import ttk


class LabeledScale(tk.Canvas):

    def __init__(self, master=None, variable=None, from_=0, to=10, **kw):
        self._label_top = kw.pop('compound', 'top') == 'top'

        tk.Canvas.__init__(self, master, **kw)
        self._variable = variable or tk.IntVar(master)
        self._variable.set(from_)
        self._last_valid = from_

        # use style to set the Canvas background color
        self._style = ttk.Style(self)
        self.configure(bg=self._style.lookup('Horizontal.TScale', 'background'))
        # create the scale
        self.scale = ttk.Scale(self, variable=self._variable, from_=from_, to=to)
        self.scale.bind('<<RangeChanged>>', self._adjust)

        # put scale in canvas
        self._scale = self.create_window(0, 0, window=self.scale, anchor='nw')
        # put label in canvas (the position will be updated later)
        self._label = self.create_text(0, 0, text=self._variable.get(),
                                       fill=self._style.lookup('TLabel', 'foreground'),
                                       anchor='s' if self._label_top else 'n')
        # adjust canvas height to fit the whole content
        bbox = self.bbox(self._label)
        self.configure(width=self.scale.winfo_reqwidth(),
                       height=self.scale.winfo_reqheight() + bbox[3] - bbox[1])
        # bindings and trace to update the label
        self.__tracecb = self._variable.trace_variable('w', self._adjust)
        self.bind('<Configure>', self._adjust)
        self.bind('<Map>', self._adjust)
        # update sizes, positions and appearances on theme change
        self.bind('<<ThemeChanged>>', self._on_theme_change)

    def destroy(self):
        """Destroy this widget and possibly its associated variable."""
        try:
            self._variable.trace_vdelete('w', self.__tracecb)
        except AttributeError:
            pass
        else:
            del self._variable
        super().destroy()
        self.label = None
        self.scale = None

    def _on_theme_change(self, *args):
        """Update position and appearance on theme change."""
        def adjust_height():
            bbox = self.bbox(self._label)
            self.configure(height=self.scale.winfo_reqheight() + bbox[3] - bbox[1])

        self.configure(bg=self._style.lookup('Horizontal.TScale', 'background'))
        self.itemconfigure(self._label, fill=self._style.lookup('TLabel', 'foreground'))
        self._adjust()
        self.after_idle(adjust_height)

    def _adjust(self, *args):
        """Adjust the label position according to the scale."""
        def adjust_label():
            self.update_idletasks() # "force" scale redraw
            x, y = self.scale.coords()
            if self._label_top:
                y = 0
            else:
                y = self.scale.winfo_reqheight()
            # avoid that the label goes off the canvas
            bbox = self.bbox(self._label)
            x = min(max(x, 0), self.winfo_width() - (bbox[2] - bbox[0])/2)
            self.coords(self._label, x, y)  # move label
            self.configure(scrollregion=self.bbox('all'))
            self.yview_moveto(0)  # make sure everything is visible

        self.itemconfigure(self._scale, width=self.winfo_width())
        from_ = ttk._to_number(self.scale['from'])
        to = ttk._to_number(self.scale['to'])
        if to < from_:
            from_, to = to, from_
        newval = self._variable.get()
        if not from_ <= newval <= to:
            # value outside range, set value back to the last valid one
            self.value = self._last_valid
            return

        self._last_valid = newval
        self.itemconfigure(self._label, text=newval)
        self.after_idle(adjust_label)

    @property
    def value(self):
        """Return current scale value."""
        return self._variable.get()

    @value.setter
    def value(self, val):
        """Set new scale value."""
        self._variable.set(val)

root = tk.Tk()
style = ttk.Style(root)
style.theme_use('alt')

scale = LabeledScale(root, from_=0, to=100, compound='bottom')
scale.pack(expand=True, fill='x')

root.mainloop()