Tk-小部件概述 - 芒果文档

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📜 Tk-小部件概述

📅 最后修改于: 2020-10-16 06:33:23 🧑 作者: Mango

基于Tk的应用程序的基本组件称为小部件。组件有时也称为窗口，因为在Tk中，“窗口”和“小部件”通常可以互换使用。 Tk是一个软件包，提供了丰富的图形组件集，可用于使用Tcl创建图形应用程序。

Tk提供了一系列的小部件，从基本的GUI小部件（如按钮和菜单）到数据显示小部件。这些小部件具有很高的可配置性，因为它们具有默认配置，因此易于使用。

Tk应用程序遵循小部件层次结构，其中可以将任意数量的小部件放置在另一个小部件中，而那些小部件则放置在另一个小部件中。 Tk程序中的主窗口小部件称为根窗口小部件，可以通过创建TkRoot类的新实例来创建。

创建小部件

下面给出了创建小部件的语法。

type variableName arguments options

这里的类型是指小部件类型，如按钮，标签等。根据每个小部件的个别语法，参数可以是可选的，也可以是必需的。选项范围从大小到每个组件的格式。

窗口小部件使用类似于命名包的结构。在Tk中，根窗口用句点（。）命名，窗口中的元素（例如button）命名为.myButton1。变量名称应以小写字母，数字或标点符号（句点除外）开头。在第一个字符，其他字符可以是大写或小写字母，数字或标点符号（句点除外）。建议使用小写字母开头标签。

可以使用诸如红色，绿色等名称来声明颜色。它也可以使用以＃表示的十六进制。十六进制数字的数量可以是3、6、9或12。

默认单位是像素，当我们不指定尺寸时使用。其他尺寸是i表示英寸，m表示毫米，c表示厘米，p表示点。

所有小部件都有很多可用的常用选项，下表中列出了这些选项-

Sr.No.	Syntax & Description
1	-background color Used to set background color for widget.
2	-borderwidth width Used to draw with border in 3D effects.
3	-font fontDescriptor Used to set font for widget.
4	-foreground color Used to set foreground color for widget.
5	-height number Used to set height for widget.
6	-highlightbackground color Used to set the color rectangle to draw around a widget when the widget does not have input focus.
7	-highlightcolor color Used to set the color rectangle to draw around a widget when the widget has input focus.
8	-padx number Sets the padx for the widget.
9	-pady number Sets the pady for the widget.
10	-relief condition Sets the 3D relief for this widget. The condition may be raised, sunken, flat, ridge, solid, or groove.
11	-text text Sets the text for the widget.
12	-textvariable varName Variable associated with the widget. When the text of widget changes, the variable is set with text of widget.
13	-width number Sets the width for widget.

一个简单的选项示例如下所示。

#!/usr/bin/wish

grid [label .myLabel -background red -text "Hello World" -relief ridge -borderwidth 3]
   -padx 100 -pady 100

当我们运行上面的程序时，我们将得到以下输出。

Hello World选项

可用小部件的列表分类如下-

Sr.No.	Widget & Description
1	Label Widget for displaying single line of text.
2	Button Widget that is clickable and triggers an action.
3	Entry Widget used to accept a single line of text as input.
4	Message Widget for displaying multiple lines of text.
5	Text Widget for displaying and optionally edit multiple lines of text.
6	Toplevel Window with all borders and decorations provided by the Window manager.

Sr.No.	Widget & Description
1	Frame Container widget to hold other widgets.
2	Place Widget to hold other widgets in specific place with coordinates of its origin and an exact size.
3	Pack Simple widget to organize widgets in blocks before placing them in the parent widget.
4	Grid Widget to nest widgets packing in different directions.

Sr.No.	Widget & Description
1	Radiobutton Widget that has a set of on/off buttons and labels, one of which may be selected.
2	Checkbutton Widget that has a set of on/off buttons and labels, many of which may be selected..
3	Menu Widget that acts as holder for menu items.
4	Listbox Widget that displays a list of cells, one or more of which may be selected.

Sr.No.	Widget & Description
1	Dialog Widget for displaying dialog boxes.
2	Spinbox Widget that allows users to choose numbers.
3	Combobox Widget that combines an entry with a list of choices available to the use.
4	Notebook Tabbed widget that helps to switch between one of several pages, using an index tab.
5	Progressbar Widget to provide visual feedback to the progress of a long operation like file upload.
6	Treeview Widget to display and allow browsing through a hierarchy of items more in form of tree.
7	Scrollbar Scrolling widgets without a text or canvas widgets.
8	Scale Scale widget to choose a numeric value through sliders.

Sr.No.	Widget & Description
1	Canvas Drawing widget for displaying graphics and images..

在接下来的章节中，我们将介绍所有这些小部件。