QT Development (22)--qmainwindow main window

QT Development (22)--qmainwindow main window I. Introduction of the main window

The main window in the application is a top-level window that interacts with the user for a long time, providing most of the functionality of the application, usually the first window after the application is launched, which typically consists of a main window and multiple dialog boxes.

QT directly supports the main window, Qmainwindow is the base class for the main window in Qt, and is a container-type component that inherits from the Qwidget class.

The Qmainwindow interior encapsulates the menu bar, toolbars, central components, docking components, status bars, and more.

Qmainwindow has a layout manager built in, and the basic component layout is as follows:

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Second, the menu bar

QT provides predefined menu-related class components, menu bar qmenubar, drop-down menu Qmenu and menu item qaction.

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qmenubar* MB = MenuBar ();

qmenu* menu = new Qmenu ("File (&f)");

Qaction *action = new Qaction (text, NULL);

Menu->addaction (action);

Mb->addmenu (menu);

Shortcut key Settings

Action->setshortcut (Qkeysequence (KEY));

Qkeysequence is a class in Qt that is related to shortcut keys, which are constants that represent key values in QT.

Third, Tool Bar

Toolbars are areas in the application that integrate various features using shortcuts, not components that the application must exist, and the elements of the toolbar can be various window components, but usually exist as icon buttons.

QT provides predefined toolbar-related components, toolbar Qtoolbar, and shortcut item qaction.

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1. How to use the toolbar

Creating toolbars

Qtoolbar *TB = Addtoolbar ("ToolBar");

To create a toolbar option

qaction * action = new Qaction ("", NULL);

Action->settooltip ("Open");

Action->seticon (Qicon ("/res/pic/open.png"));

add toolbar options to Toolbars

Tb->addaction (action);

2.qtoolbar utility function

void setfloatable (bool floatable) set the toolbar to float

void setmovable (bool movable) sets the toolbar to be movable

void seticonsize (const qsize & iconsize) Set the icon size of the toolbar

3. Toolbar Instances

Any qwidget component in QT can be added to the Qtollbar component.

qtoolbar* tb = Addtoolbar ("Tool Bar");

qaction* action = new Qaction ("", NULL);

Tb->setfloatable (FALSE);

Tb->setmovable (FALSE);

Action->settooltip ("Open");

Action->seticon (Qicon (":/res/open.png"));

Tb->addaction (action);

qpushbutton* B = new Qpushbutton ("button");

qlabel* L = new Qlabel ("Label");

qlineedit* e = new Qlineedit ();

Tb->addwidget (b);

Tb->addwidget (l);

Tb->addwidget (e) ;

iv. status Bar

The status bar is the area in the application where you output summary information, usually at the bottom of the window. The status bar displays the following message types:

A, real-time messages, such as the current program status

B, permanent messages, such as program versions, development agencies

C, progress message, progress display

The predefined status bar-related component status bar is provided in Qt Qstatusbar,qstatusbar is a container-type component and can be the parent component of any component Qwidget.

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General design principles for the QT status bar:

A, the left area of the status bar is used to output real-time messages

B. The right area of the status bar is used to output a permanent message

Therefore,the AddWidget function is used to add components to the left area of the status bar, and the Addpermanentwidget function is used to add components to the right area of the status bar.

The status bar uses the following methods:

qstatusbar* sb = StatusBar ();

qlabel* label = new Qlabel ("CopyRight @ Scorpio Studio 2016");

if (label! = NULL)

{

Line.setminimumwidth (120);

Line.setalignment (Qt::aligncenter);

Line.settext ("Ln:1 col:1");

Label->setminimumwidth (160);

Label->setalignment (Qt::aligncenter);

Sb->addpermanentwidget (New Qlabel ());

Sb->addpermanentwidget (&line);

Sb->addpermanentwidget (label);

}

Five, Text editing Components

Three types of text editing components are pre-defined in QT to meet different development needs.

A, Qlineedit Single-line text editing component

B, Qtextedit Multi-line Rich text editing component

C, Qplaintextedit Multi-line Plain text editing component

Class inheritance diagram for qt text editing components:

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The text editing component in Qt has a right-click Popup and shortcut key function.

Use of the text editor:

To set the parent component of a text editor

maineditor.setparent (this);

set the text editor as a central component

Setcentralwidget (&maineditor);

This article from "Life is endless, struggle not only" blog, declined reprint!

QT Development (22)--qmainwindow main window