1. QHBoxLayout

Widget::Widget(QWidget *parent)
    : QWidget(parent) {

    QPushButton *button1 = new QPushButton("One");
    QPushButton *button2 = new QPushButton("Two");
    QPushButton *button3 = new QPushButton("Three");
    QPushButton *button4 = new QPushButton("Four");
    QPushButton *button5 = new QPushButton("Five");

    QHBoxLayout *layout = new QHBoxLayout(this);

    layout->addWidget(button1);
    layout->addWidget(button2);
    layout->addWidget(button3);
    layout->addWidget(button4);
    layout->addWidget(button5);
}

Widget::~Widget() {
}

2. HVBoxLayout

#include "widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent) {

    QPushButton *button1 = new QPushButton("One");
    QPushButton *button2 = new QPushButton("Two");
    QPushButton *button3 = new QPushButton("Three");
    QPushButton *button4 = new QPushButton("Four");
    QPushButton *button5 = new QPushButton("Five");

    QVBoxLayout *layout = new QVBoxLayout();

    layout->addWidget(button1);
    layout->addWidget(button2);
    layout->addWidget(button3);
    layout->addWidget(button4);
    layout->addWidget(button5);
	
	setLayout(layout); // 如果layout构造函数使用this，就可以省略这句代码
}

Widget::~Widget() {
}

3. QHBoxLayout 和 QVBoxLayout 复合布局

#include "widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent) {

    QPushButton *button1 = new QPushButton("One");
    QPushButton *button2 = new QPushButton("Two");
    QPushButton *button3 = new QPushButton("Three");
    QPushButton *button4 = new QPushButton("Four");
    QPushButton *button5 = new QPushButton("Five");

    QHBoxLayout *layout = new QHBoxLayout(this);

    layout->addWidget(button1);
    layout->addWidget(button2);
    layout->addWidget(button3);
    layout->addWidget(button4);
    layout->addWidget(button5);

    QPushButton *button11 = new QPushButton("1");
    QPushButton *button22 = new QPushButton("2");
    QPushButton *button33 = new QPushButton("3");
    QPushButton *button44 = new QPushButton("4");
    QPushButton *button55 = new QPushButton("5");

    QVBoxLayout *vLayout = new QVBoxLayout();
    vLayout->addWidget(button11);
    vLayout->addWidget(button22);
    vLayout->addWidget(button33);
    vLayout->addWidget(button44);
    vLayout->addWidget(button55);

    layout->addLayout(vLayout);
}

Widget::~Widget() {
}

• 设定控件间固定的间距

// button2 和 button3之间间距100
layout->addWidget(button1);
layout->addWidget(button2);
layout->addSpacing(100);
layout->addWidget(button3);
layout->addWidget(button4);
layout->addWidget(button5);

• 控件间可以*拉伸

// 拉伸整体窗口的时候是在button2 和 button3之间可以*拉伸
layout->addWidget(button1);
layout->addWidget(button2);
layout->addStretch();
layout->addWidget(button3);
layout->addWidget(button4);
layout->addWidget(button5);

• 间隔一定距离基础上进行缩小或者拉伸

// button4 和 button5 之间默认间隔距离100，随着整体窗口的拉伸，这个距离可以进一步拉伸且不会影响其他按钮的大小
layout->addWidget(button1);
layout->addWidget(button2);
layout->addWidget(button3);
layout->addWidget(button4);
layout->addSpacerItem(new QSpacerItem(100,100, QSizePolicy::MinimumExpanding));
layout->addWidget(button5);

默认大小

拉伸

4. QFormLayout

QLineEdit *nameLineEdit = new QLineEdit();
QLineEdit *emailLineEdit = new QLineEdit();
QLineEdit *ageSpinBox = new QLineEdit();

QFormLayout *formLayout = new QFormLayout;
formLayout->addRow(tr("&Name:"), nameLineEdit);
formLayout->addRow(tr("&Email:"), emailLineEdit);
formLayout->addRow(tr("&Age:"), ageSpinBox);
// formLayout->setFieldGrowthPolicy(QFormLayout::FieldGrowthPolicy::AllNonFixedFieldsGrow); // 这段代码可以对QLineEdit这一列进行拉伸
setLayout(formLayout);

5. QGridLayout

QLineEdit *nameLineEdit = new QLineEdit();
QLineEdit *emailLineEdit = new QLineEdit();
QLineEdit *ageSpinBox = new QLineEdit();

QLabel *nameLabel = new QLabel(tr("&Name:"));
nameLabel->setBuddy(nameLineEdit);

QLabel *emailLabel = new QLabel(tr("&Name:"));
emailLabel->setBuddy(emailLineEdit);

QLabel *ageLabel = new QLabel(tr("&Name:"));
ageLabel->setBuddy(ageSpinBox);

QGridLayout *gridLayout = new QGridLayout;
gridLayout->addWidget(nameLabel, 0, 0);
gridLayout->addWidget(nameLineEdit, 0, 1);
gridLayout->addWidget(emailLabel, 1, 0);
gridLayout->addWidget(emailLineEdit, 1, 1);
gridLayout->addWidget(ageLabel, 2, 0);
gridLayout->addWidget(ageSpinBox, 2, 1);
setLayout(gridLayout);

6. QStackedLayout

QWidget *firstPageWidget = new QWidget;
QLabel *firstLabel = new QLabel("first widget", firstPageWidget);
QWidget *secondPageWidget = new QWidget;
QLabel *secondLabel = new QLabel("second widget", secondPageWidget);
QWidget *thirdPageWidget = new QWidget;
QLabel *thirdLabel = new QLabel("third widget", thirdPageWidget);

QStackedLayout *stackedLayout = new QStackedLayout;
stackedLayout->addWidget(firstPageWidget);
stackedLayout->addWidget(secondPageWidget);
stackedLayout->addWidget(thirdPageWidget);

QVBoxLayout *mainLayout = new QVBoxLayout;
mainLayout->addLayout(stackedLayout);
setLayout(mainLayout);

stackedLayout->setCurrentIndex(0); // 设置 firstPageWidget为当前显示的widget
//stackedLayout->setCurrentIndex(1); // 设置 secondPageWidget为当前显示的widget
//stackedLayout->setCurrentIndex(2); // 设置 thirdPageWidget为当前显示的widget