tkinter按钮绑定和行为问题

Question

我试图找出如何使Enter键的行为与tkinter中的空格键相同。到目前为止，唯一出现的就是将Enter键绑定到按钮。到目前为止，它的功能还不错。

但是：在视觉上它们是不一样的。当您按下空格键时，按钮的释放会立即变为SUNKEN。按键绑定或调用invoke（）不会具有相同的视觉效果。

[试图找到答案时，我可能发现了一个错误。当用空格键按下按钮约5至10秒钟时，RELIEF将永久更改为SUNKEN。无论您等待多长时间。因此，这是我需要解决的另一件事。也许在函数调用后重置按钮的状态。...我会尝试的。

以下示例代码无法正常工作：

import tkinter as tk

root = tk.Tk()
root.geometry("300x200")
# if you press the enter key, buttons will call their own invoke function
# yet they won't show the effect of pressing space or clicking a button.
# When you press space or click a button the RELIEF will get changed.
# HOWEVER: When you hold space, the relief will get changed to SUNKEN permanently.
# That might me a bug.
root.bind_class("Button", "<Key-Return>", lambda event: event.widget.invoke())

def onclick():
    print("You clicked the button")

button = tk.Button(root, text="click me", command=onclick)
button.pack()

# it's not a callback issue that the button remains SUNKEN after holding space for a bit.
button2 = tk.Button(root, text="this button has no command")    
button2.pack()

root.mainloop()

编辑：我在win10上。

Answer 1

发布的解决方案@ acw1668就像是一种魅力。

现在的代码是：

import tkinter as tk

root = tk.Tk()
root.geometry("300x200")
# When you hold space, the relief will get changed to SUNKEN permanently.
# That might me a bug.
root.bind_class("Button", "<Key-Return>", lambda event: event.widget.event_generate("<space>"))

def onclick():
    print("You clicked the button")

button = tk.Button(root, text="click me", command=onclick)
button.pack()

# it's not a callback issue that the button remains SUNKEN after holding space for a bit.
button2 = tk.Button(root, text="this button has no command")    
button2.pack()

root.mainloop()

但是它不能解决凹下去的问题。