如何检测Tkinter Canvas自移动元素的鼠标悬停/离开事件？

Tkinter的<Enter>和<Leave>事件仅在鼠标主动移动进入或离开元素时触发。当Canvas元素自身移动时，即使鼠标相对于元素的位置关系发生变化（比如元素移开鼠标、或移到鼠标上方），Tkinter不会自动检测这种变化，因此不会触发对应的事件，导致悬停状态无法自动更新。

通过主动跟踪鼠标位置，在元素更新位置后手动检查鼠标是否处于元素的包围盒范围内，以此来触发悬停状态的切换逻辑。具体修改步骤如下：

1. 跟踪鼠标当前位置：给Canvas绑定<Motion>事件，实时记录鼠标坐标
2. 给交互式文本添加悬停状态标记，避免重复执行状态切换
3. 在元素更新位置后，手动检查鼠标与元素的位置关系，更新悬停状态

import math
class Easing:
    @staticmethod
    def linear(t, b, c, d):
        return c*t/d + b
    @staticmethod
    def inSine(t, b, c, d):
        return -c * math.cos(t/d * (math.pi/2)) + c + b

def apply_easing(easing, t, beginning, destination, duration):
    return {key: easing(t, beginning[key], destination[key] - beginning[key], duration) for key in destination.keys()}

class Tween:
    easing = Easing()
    _playing = []
    def __init__(self, duration, subject, target, easing=easing.linear, options={"loop":"forever"}):
        self.duration = duration
        self.subject = subject
        self.target = target
        self.initial = {key: self.subject[key] for key in self.target.keys()}
        self.easing = easing
        self.loop = options.get("loop", "once") if options is not None else "once"
        self.playbackdirection = "forward"
        self.elapsed_time = 0
        self.play()

    def play(self):
        if not self in Tween._playing:
            Tween._playing.append(self)

    def stop(self):
        Tween._playing.remove(self)
        
    def update(self, deltatime):
        if self.elapsed_time >= self.duration:
            if self.loop == "once":
                self.stop()

            if self.loop == "forever":
                self.playbackdirection = "backward"

        if self.elapsed_time <= 0:
            self.playbackdirection = "forward"

        if self.playbackdirection == "forward":
            self.elapsed_time += deltatime
        elif self.playbackdirection == "backward":
            self.elapsed_time -= deltatime

        result = apply_easing(self.easing, self.elapsed_time, 
            self.initial, 
            self.target, 
            self.duration)
        self.subject.update(result)
        return result


from tkinter import *
import time

WIDTH=640
HEIGHT=480

root = Tk()
root.title("Minimal Example")
root.geometry(f"{WIDTH}x{HEIGHT}")

# 全局跟踪鼠标位置
mouse_pos = [0, 0]

class InteractiveText:
    def __init__(self, canvas, x, y, content, default_fill='black'):
        self.position = {"x":x, "y":y}
        self.content = content
        self.canvas = canvas
        self.default_fill = default_fill
        self.text = canvas.create_text(self.position["x"], self.position["y"], text=self.content, font = ("monaco", 24), fill=default_fill)
        self.canvas.tag_bind(self.text, '<Enter>', lambda event: self.on_hover())
        self.canvas.tag_bind(self.text, '<Leave>', lambda event: self.on_leave())
        self.canvas.tag_bind(self.text, '<Button-1>', self.on_click)
        # 添加悬停状态标记，避免重复触发
        self.is_hovered = False

    def update_position(self):
        self.canvas.coords(self.text, self.position["x"], self.position["y"])
        # 更新位置后，手动检查鼠标是否在元素范围内
        self.check_hover_state()

    def check_hover_state(self):
        # 获取文本元素的包围盒
        bbox = self.canvas.bbox(self.text)
        if not bbox:
            return
        x1, y1, x2, y2 = bbox
        # 判断鼠标是否在包围盒内
        mouse_in_bbox = (x1 <= mouse_pos[0] <= x2) and (y1 <= mouse_pos[1] <= y2)
        
        if mouse_in_bbox and not self.is_hovered:
            self.on_hover()
        elif not mouse_in_bbox and self.is_hovered:
            self.on_leave()

    def on_hover(self):        
        self.canvas.itemconfig(self.text, fill="red")
        self.is_hovered = True

    def on_leave(self):
        self.canvas.itemconfig(self.text, fill=self.default_fill)
        self.is_hovered = False

    def on_click(self, event):
        print(self.content, "clicked!")


class Scene:
    def __init__(self):
        self.canvas = Canvas(root, width=WIDTH, height=HEIGHT, bg="white")
        self.canvas.pack()
        self.canvas_items = []
        # 绑定鼠标移动事件，跟踪位置
        self.canvas.bind('<Motion>', self.update_mouse_pos)

    def update_mouse_pos(self, event):
        global mouse_pos
        mouse_pos = [event.x, event.y]

    def text(self, x, y, content):
        t = InteractiveText(self.canvas, x, y, content)
        self.canvas_items.append(t)
        return t
    def rect(self, x, y, w, h):
        r = MyRect(self.canvas, x, y, w, h)
        self.canvas_items.append(r)
        return r

def update(lastFrameTime):
    currentTime = time.time()
    for tw in Tween._playing:
        tw.update(currentTime - lastFrameTime)
    for obj in CURRENT_SCENE.canvas_items:
        obj.update_position()

    next_deltatime = int(round(lastFrameTime + 1/60*1000 - currentTime, 0))
    # 避免负延迟导致异常
    next_deltatime = max(next_deltatime, 1)
    root.after(next_deltatime, update, currentTime)

root.after(0, update, time.time())


mainmenu =Scene()
CURRENT_SCENE = mainmenu

# 主菜单按钮
playtext = mainmenu.text(-100, 65, "Play game")
quittext = mainmenu.text(WIDTH+150, 150, "Quit")

Tween(4.99, playtext.position, {"x": WIDTH/2+25, "y":50},  Tween.easing.linear)
Tween(4.99, quittext.position, {"x": WIDTH/2, "y":390}, Tween.easing.inSine)

root.mainloop()

• 新增mouse_pos全局变量存储鼠标坐标，通过Scene类中Canvas的<Motion>事件实时更新
• InteractiveText类添加is_hovered标记，防止重复触发状态切换
• 在update_position方法末尾新增check_hover_state逻辑，通过canvas.bbox()获取元素边界，判断鼠标是否在范围内，主动触发on_hover或on_leave

内容的提问来源于stack exchange，提问作者zitot