Tkinter 中的小部件是什么？

Tkinter是 Python 的标准 GUI（图形用户界面）包。 tkinter为我们提供了各种常见的 GUI 元素，我们可以使用它们来构建界面——例如按钮、菜单和各种类型的输入字段和显示区域。我们称这些元素为 Widgets 。

小部件

一般来说，小部件是图形用户界面 (GUI) 的一个元素，它显示/说明信息或为用户提供与操作系统交互的方式。在Tkinter中，小部件是对象；表示按钮、框架等的类的实例。

每个单独的小部件都是一个Python对象。创建小部件时，您必须将其父级作为参数传递给小部件创建函数。唯一的例外是“根”窗口，它是包含其他所有内容且没有父窗口的顶级窗口。

例子 ：

Python

from tkinter import *
  
  
# create root window
root = Tk()                           
  
# frame inside root window
frame = Frame(root)                  
  
# geometry method
frame.pack()                          
  
# button inside frame which is 
# inside root
button = Button(frame, text ='Geek')  
button.pack()                         
  
# Tkinter event loop
root.mainloop()

输出 ：

小部件类

Tkinter 支持下面提到的核心小部件——

Widgets	Description
Label	It is used to display text or image on the screen
Button	It is used to add buttons to your application
Canvas	It is used to draw pictures and others layouts like texts, graphics etc.
ComboBox	It contains a down arrow to select from list of available options
CheckButton	It displays a number of options to the user as toggle buttons from which user can select any number of options.
RadiButton	It is used to implement one-of-many selection as it allows only one option to be selected
Entry	It is used to input single line text entry from user
Frame	It is used as container to hold and organize the widgets
Message	It works same as that of label and refers to multi-line and non-editable text
Scale	It is used to provide a graphical slider which allows to select any value from that scale
Scrollbar	It is used to scroll down the contents. It provides a slide controller.
SpinBox	It is allows user to select from given set of values
Text	It allows user to edit multiline text and format the way it has to be displayed
Menu	It is used to create all kinds of menu used by an application

几何管理

创建一个新的小部件并不意味着它会出现在屏幕上。为了显示它，我们需要调用一个特殊的方法： grid 、 pack （上面的例子）或者place 。

Method	Description
pack()	The Pack geometry manager packs widgets in rows or columns.
grid()	The Grid geometry manager puts the widgets in a 2-dimensional table.  The master widget is split into a number of rows and columns, and each “cell” in the resulting table can hold a widget.
place()	The Place geometry manager is the simplest of the three general geometry managers provided in Tkinter.  It allows you explicitly set the position and size of a window, either in absolute terms, or relative to another window.