QT常见Layout布局器使用

布局简介

为什么要布局？通过布局拖动不影响鼠标拖动窗口的效果等优点.QT设计器布局比较固定，不方便后期修改和维护；在Qt里面布局分为四个大类 ：

盒子布局：QBoxLayout

网格布局：QGridLayout

表单布局：QFormLayout

抽屉布局：QStackedLayout

分页显示：QTabWidget

分割器：Splitter

QBoxLayout

一般使用它的两个子类QHBoxLayout 和 QVBoxLayout 负责水平和垂直布局

QVBoxLayout 基本使用

mainwindow.cpp(后面例程都在mainwindow.cpp演示):

#include "mainwindow.h"
#include <QApplication>
#include <QPushButton>
#include <QVBoxLayout>
#include <QHBoxLayout>MainWindow::MainWindow(QWidget *parent): QMainWindow(parent)
{QWidget* w=new QWidget;setCentralWidget(w);//注意MainWindow不能直接进行布局QVBoxLayout* vlayout=new QVBoxLayout;QPushButton* b1=new QPushButton("b1");QPushButton* b2=new QPushButton("b2");QPushButton* b3=new QPushButton("b3");vlayout->addWidget(b1);vlayout->addStretch(1);//增加一个伸缩量vlayout->addWidget(b2);vlayout->addStretch(1);//增加一个伸缩量vlayout->addWidget(b3);vlayout->addStretch(2);//增加一个伸缩量centralWidget()->setLayout(vlayout);this->resize(300, 300);
}MainWindow::~MainWindow()
{}

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>class MainWindow : public QMainWindow
{Q_OBJECTpublic:MainWindow(QWidget *parent = 0);~MainWindow();
};#endif // MAINWINDOW_H

main.cpp

#include "mainwindow.h"
#include <QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);MainWindow w;w.show();return a.exec();
}

QHBoxLayout基本使用

#include "mainwindow.h"
#include <QApplication>
#include <QPushButton>
#include <QVBoxLayout>
#include <QHBoxLayout>MainWindow::MainWindow(QWidget *parent): QMainWindow(parent)
{this->setWindowTitle("水平布局");QWidget* w=new QWidget;setCentralWidget(w);QHBoxLayout* hlayout=new QHBoxLayout;QPushButton* b1=new QPushButton("b1");QPushButton* b2=new QPushButton("b2");QPushButton* b3=new QPushButton("b3");hlayout->addWidget(b1);hlayout->addStretch(1);//增加一个伸缩量hlayout->addWidget(b2);hlayout->addStretch(1);//增加一个伸缩量hlayout->addWidget(b3);hlayout->addStretch(2);//增加一个伸缩量centralWidget()->setLayout(hlayout);this->resize(300, 300);
}

 QHBoxLayout和QVBoxLayout综合使用

可以结合QGroupBox容器进行布局

#include "mainwindow.h"
#include <QApplication>
#include <QPushButton>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QGroupBox>
#include <QRadioButton>
MainWindow::MainWindow(QWidget *parent): QMainWindow(parent)
{this->setWindowTitle("垂直布局");QWidget* w=new QWidget;setCentralWidget(w);QVBoxLayout* container=new QVBoxLayout;QGroupBox *hobby_box = new QGroupBox("爱好");QVBoxLayout* v_layout=new QVBoxLayout;QRadioButton* btn1 = new QRadioButton("抽烟");QRadioButton* btn2 = new QRadioButton("喝酒");QRadioButton* btn3 = new QRadioButton("玩乐");v_layout->addWidget(btn1);v_layout->addWidget(btn2);v_layout->addWidget(btn3);hobby_box->setLayout(v_layout);QGroupBox* gender_box = new QGroupBox("性别");QHBoxLayout* h_layout = new QHBoxLayout();QRadioButton* btn4 =  new QRadioButton("男");QRadioButton* btn5 = new QRadioButton("女");h_layout->addWidget(btn4);h_layout->addWidget(btn5);gender_box->setLayout(h_layout);container->addWidget(hobby_box);container->addWidget(gender_box);centralWidget()->setLayout(container);this->resize(300, 300);
}

 

垂直和水平布局技巧 

QGridLayout

QGridLayout基本使用

网格布局，有的人称之为九宫格布局；示例如下：

#include "mainwindow.h"
#include <QApplication>
#include <QPushButton>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QGroupBox>
#include <QRadioButton>
#include <QStringList>
#include <QLineEdit>
#include <QGridLayout>MainWindow::MainWindow(QWidget *parent): QMainWindow(parent)
{this->setWindowTitle("网格布局");QWidget* w=new QWidget;setCentralWidget(w);QVBoxLayout* container=new QVBoxLayout;QPushButton* m_buttons[20];const char* btnText[20] ={"7", "8", "9", "+", "(","4", "5", "6", "-", ")","1", "2", "3", "*", "<-","0", ".", "=", "/", "C"};QLineEdit* edit = new QLineEdit();edit->setPlaceholderText("请输入内容");QGridLayout* grid = new QGridLayout();int line_number = 0;int col_number = 0;for(line_number = 0;line_number < 4;line_number++){// 此时line_number是第几行for(col_number = 0;col_number < 5;col_number++){// 此时col_number是第几列m_buttons[line_number*5 + col_number] = new QPushButton();m_buttons[line_number*5 + col_number]->setText(btnText[line_number*5 + col_number]);grid->addWidget(m_buttons[line_number*5 + col_number], line_number, col_number);}}container->addWidget(edit);container->addLayout(grid);centralWidget()->setLayout(container);this->resize(300, 300);
}

网格布局技巧

QFormLayout

QFormLayout基本使用

表单布局，一般适用于提交数据form表单。比如： 登录，注册类似的场景

#include "mainwindow.h"
#include <QApplication>
#include <QPushButton>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QGroupBox>
#include <QRadioButton>
#include <QStringList>
#include <QLineEdit>
#include <QGridLayout>
#include <QFormLayout>
#include<QTextCodec>
#define chineseToQString(pChineseText)  QTextCodec::codecForName("GB2312")->toUnicode(pChineseText)MainWindow::MainWindow(QWidget *parent): QMainWindow(parent)
{this->setWindowTitle(chineseToQString("表单布局"));QWidget* w=new QWidget;setCentralWidget(w);QVBoxLayout* container=new QVBoxLayout;QFormLayout* form_layout = new QFormLayout();QLineEdit* edit1 = new QLineEdit();edit1->setPlaceholderText(chineseToQString("请输入账号"));form_layout->addRow(chineseToQString("账号："), edit1);QLineEdit* edit2 = new QLineEdit();edit2->setPlaceholderText(chineseToQString("请输入密码"));form_layout->addRow((chineseToQString("密码：")), edit2);QPushButton* login_btn = new QPushButton(chineseToQString("登录"));login_btn->setFixedSize(100, 30);container->addLayout(form_layout);container->addWidget(login_btn,1,Qt::AlignRight);centralWidget()->setLayout(container);this->setFixedSize(300, 150);
}

表单布局技巧

QStackedLayout

QStackedLayout基本使用

抽屉式布局，或叫堆叠布局，提供了多页面切换的布局，一次只能看到一个界面。

#include "mainwindow.h"
#include <QApplication>
#include <QPushButton>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QGroupBox>
#include <QRadioButton>
#include <QStringList>
#include <QLineEdit>
#include <QGridLayout>
#include <QFormLayout>
#include <QTextCodec>
#include <QListWidget>
#include <QLabel>
#include <QStackedLayout>
#define chineseToQString(pChineseText)  QTextCodec::codecForName("GB2312")->toUnicode(pChineseText)MainWindow::MainWindow(QWidget *parent): QMainWindow(parent)
{this->setWindowTitle(chineseToQString("抽屉/堆叠布局"));QWidget* w=new QWidget;setCentralWidget(w);QListWidget *listWidget = new QListWidget(); //创建一个列表listWidget->setMinimumWidth(150);listWidget->setFont(QFont("宋体",14));listWidget->addItem("QPushButton");listWidget->addItem("QLabel");listWidget->addItem("QLineEdit");//新建 3 个窗口，分别放置文本框、按钮和单行输入框QWidget *widget1 = new QWidget;widget1->setMinimumSize(400,400);QVBoxLayout* widget1Layout = new QVBoxLayout;QVBoxLayout* widget2Layout = new QVBoxLayout;QVBoxLayout* widget3Layout = new QVBoxLayout;QPushButton *but1 = new QPushButton(chineseToQString("这是一个按钮1"));QPushButton *but2 = new QPushButton(chineseToQString("这是一个按钮2"));widget1Layout->addWidget(but1);widget1Layout->addWidget(but2);widget1->setLayout(widget1Layout);QWidget *widget2 = new QWidget;widget2->setMinimumSize(400,400);QLabel *lab1 = new QLabel(chineseToQString("这是一个文本框1"));QLabel *lab2 = new QLabel(chineseToQString("这是一个文本框2"));widget2Layout->addWidget(lab1);widget2Layout->addWidget(lab2);widget2->setLayout(widget2Layout);QWidget *widget3 = new QWidget;widget3->setMinimumSize(400,400);QLineEdit* edit1 = new QLineEdit(chineseToQString("这是一个单行输入框1"));QLineEdit* edit2 = new QLineEdit(chineseToQString("这是一个单行输入框2"));widget3Layout->addWidget(edit1);widget3Layout->addWidget(edit2);widget3->setLayout(widget3Layout);//创建一个分组布局，将 3 个窗口添加到分组控件中QStackedLayout *stackedLayout = new QStackedLayout;stackedLayout->addWidget(widget1);stackedLayout->addWidget(widget2);stackedLayout->addWidget(widget3);QPushButton* changeBtn = new QPushButton(chineseToQString("点击切换界面"));QVBoxLayout* vLayout = new QVBoxLayout;QHBoxLayout* container=new QHBoxLayout;vLayout->addWidget(listWidget);vLayout->addWidget(changeBtn);container->addLayout(vLayout,1);container->addLayout(stackedLayout,4);centralWidget()->setLayout(container);//连接信号和槽，实现当点击列表中的某一项，切换分组布局管理器显示的控件QObject::connect(listWidget,&QListWidget::currentRowChanged,stackedLayout,&QStackedLayout::setCurrentIndex);connect(changeBtn,&QPushButton::clicked,this,[=](){//也可以通过点击按钮循环切换int nextPage = (stackedLayout->currentIndex() + 1) % stackedLayout->count();stackedLayout->setCurrentIndex(nextPage);});this->setMinimumSize(600, 400);
}

抽屉布局技巧

QTabWidget

提供了便捷的分页显示功能，类似于编辑器中打开不同文件

#include "mainwindow.h"
#include <QApplication>
#include <QPushButton>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QGroupBox>
#include <QRadioButton>
#include <QStringList>
#include <QLineEdit>
#include <QGridLayout>
#include <QFormLayout>
#include <QTextCodec>
#include <QListWidget>
#include <QLabel>
#include <QStackedLayout>
#include <QTextEdit>#define chineseToQString(pChineseText)  QTextCodec::codecForName("GB2312")->toUnicode(pChineseText)MainWindow::MainWindow(QWidget *parent): QMainWindow(parent)
{this->setWindowTitle(chineseToQString("QTabWidget"));QWidget* w=new QWidget;setCentralWidget(w);QTextEdit* text1 = new QTextEdit(this);QTextEdit* text2 = new QTextEdit(this);QTextEdit* text3 = new QTextEdit(this);text1->setStyleSheet("background-color: red");text2->setStyleSheet("background-color: blue");text3->setStyleSheet("background-color: green");QTabWidget* tWidget = new QTabWidget(this);tWidget->addTab(text1,"test1.txt");tWidget->addTab(text2,"test2.txt");tWidget->addTab(text3,"test3.txt");tWidget->setTabsClosable(true); //设置可以关闭connect(tWidget,&QTabWidget::tabCloseRequested,this,[=](int index){tWidget->removeTab(index);//点击关闭后关闭此Tab});QHBoxLayout* container=new QHBoxLayout;container->addWidget(tWidget);centralWidget()->setLayout(container);this->setMinimumSize(600, 400);
}

 Splitter分割器

splitter允许用户通过拖动子部件之间的边界来控制它们的大小。任何数量的小部件都可以由单个拆分器控制。QSplitter的典型用法是创建几个小部件并使用 insertWidget()或addWidget()添加它们

#include "mainwindow.h"
#include <QApplication>
#include <QPushButton>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QGroupBox>
#include <QRadioButton>
#include <QStringList>
#include <QLineEdit>
#include <QGridLayout>
#include <QFormLayout>
#include <QTextCodec>
#include <QListWidget>
#include <QLabel>
#include <QStackedLayout>
#include <QTextEdit>
#include <QSplitter>#define chineseToQString(pChineseText)  QTextCodec::codecForName("GB2312")->toUnicode(pChineseText)MainWindow::MainWindow(QWidget *parent): QMainWindow(parent)
{this->setWindowTitle(chineseToQString("QSplitter"));QWidget* w=new QWidget;setCentralWidget(w);auto text1 = new QTextEdit(this);auto text2 = new QTextEdit(this);QSplitter* splitter = new QSplitter(this);splitter->addWidget(text1);splitter->addWidget(text2);splitter->setOpaqueResize(true);//设置为预览模式：falseQVBoxLayout* container=new QVBoxLayout;container->addWidget(splitter);centralWidget()->setLayout(container);this->setMinimumSize(600, 400);
}

 鼠标放在中间的间隔上我们便可以左右拖动他们的距离

其它相关技巧