Python Tkinter中的winfo_ismapped()和winfo_exist() _Tkinter

Tkinter提供了许多通用的窗口小部件方法或基本的窗口小部件方法, 它们几乎可以与所有可用的窗口小部件一起使用。
winfo_ismapped()方法–
此方法用于检查指定的小部件是否可见。

语法：widget.winfo_ismapped()返回值：如果窗口小部件可见(或映射), 则返回True, 否则返回False。例外：如果小部件被破坏, 则将引发错误。

# Imports tkinter and ttk module from tkinter import * from tkinter.ttk import * import time# toplevel window root = Tk()def forget(widget): widget.forget() print ( "After Forget method called. Is widget mapped? = " , bool (widget.winfo_ismapped()))def retrieve(widget): widget.pack() print ( "After retrieval of widget. Is widget mapped? = " , bool (widget.winfo_exists()))# Button widgets b1 = Button(root, text = "Btn 1" ) b1.pack()# This is used to make widget invisible b2 = Button(root, text = "Btn 2" , command = lambda : forget(b1)) b2.pack()# This will retrieve widget b3 = Button(root, text = "Btn 3" , command = lambda : retrieve(b1)) b3.pack()# infinite loop, interrupted by keyboard or mouse mainloop()

输出如下：

Python Tkinter中的winfo_ismapped()和winfo_exist()

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winfo_exists()方法–
此方法用于检查指定的小部件是否存在, 即, 该小部件是否被破坏。

语法：widget.winfo_exists()返回值：如果存在widget, 则返回True, 否则返回False。

# Imports tkinter and ttk module from tkinter import * from tkinter.ttk import *# toplevel window root = Tk()def dest(widget): widget.destroy() print ( "Destroy method called. Widget exists? = " , bool (widget.winfo_exists()))def exist(widget): print ( "Checking for existance = " , bool (widget.winfo_exists()))# Button widgets b1 = Button(root, text = "Btn 1" ) b1.pack()# This is used to destroy widget b2 = Button(root, text = "Btn 2" , command = lambda : dest(b1)) b2.pack()# This is used to check existance of the widget b3 = Button(root, text = "Btn 3" , command = lambda : exist(b1)) b3.pack()# infinite loop, interrupted by keyboard or mouse mainloop()

输出如下：