东莞市生态环境局/排名优化seo公司

布局Layout

1.Vertical Layout
2.Horizontal Layout
3.Grid Layout
4.Form Layout

sizeHint推荐尺寸

1.QSize sizeHint() 推荐尺寸只能重载修改
2.QSize size() 不包含边框的窗口尺寸

QSizePolicy::PolicyFlag
1.GrowFlag 必要时可超过推荐
2.ExpandFlag 尽可能的扩展
3.ShrinkFlag 必要时可小于推荐
4.IgnoreFlag 缺省大小被忽略

QSizePolicy::Policy
1.Fixed 0 只参考sizeHint()
2.Minimum GrowFlag 伸张和收缩 >= sizeHint()
3.Maximum ShrinkFlag 伸张和收缩 <= sizeHint()
4.Preferred GrowFlag | ShrinkFlag 默认
5.Expanding GrowFlag | ShrinkFlag | ExpandFlag
6.MinimumExpanding GrowFlag | ExpandFlag
7.Ignored ShrinkFlag | GrowFlag | IgnoreFlag

setContentsMargins

1.(int left,int top,int right,int bottom)

setSizePolicy

1.(QSizePolicy::Policy horizontal,QSizePolicy::Policy vertical)

设置最大最小尺寸
1.setMinimumSize
2.setMaximumSize3.setSpacing(6); //间距
4.setContentsMargins(11,11,11,11);//边框距离

//#include "widget.h"
#include <QApplication>
#include <QWidget>
#include <QVBoxLayout>
#include <QPushButton>
int main(int argc, char *argv[])
{QApplication a(argc, argv);QWidget *win = new QWidget();win->resize(400,400);//垂直布局 可以构造函数中传递widgetQHBoxLayout *lay = new QHBoxLayout();win->setLayout(lay);//win->show();//添加到QWidget作为QVBoxLayout的父类的QVBoxLayout中   QPushButton *but1 = new QPushButton("button1");lay->addWidget(but1);//水平 垂直Policy Fixed 使用推荐大小//80 : 25 80 : 25but1->setSizePolicy(QSizePolicy::Fixed,QSizePolicy::Fixed);//水平拉伸 垂直拉伸//80 : 25 400 : 338//尽量最大最小尺寸为推荐尺寸but1->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);//忽略推荐大小，尽量缩放but1->setSizePolicy(QSizePolicy::Ignored,QSizePolicy::Ignored);but1->setMinimumSize(100,50);but1->setMaximumSize(500,100);QPushButton *but2 = new QPushButton("button2");lay->addWidget(but2);QPushButton *but3 = new QPushButton("button3");lay->addWidget(but3);//边框距离lay->setContentsMargins(0,0,0,0);//元素间的距离lay->setSpacing(0);win->show();//没有设置setContentsMargins(0,0,0,0);//{80 : 25} {378 : 25}//设置setContentsMargins(0,0,0,0);//{80 : 25} {400 : 25}qDebug()<<but1->sizeHint().width()<<":"<<but1->sizeHint().height();qDebug()<<but1->width()<<":"<<but1->height();return a.exec();
}

QGridLayout

void addWidget(
QWidget*,
int row,
int column,
Qt::Aignment = Qt::Alignment()
)

AlignmentFlag 对齐

AlignLeft = 0x0001
AlignLeading = AlignLeft
AlignRight = 0x0002
AlignTrailing = AlignRight
AlignHCenter = 0x0004
AligJustify = 0x0008
AlignAbsolute = 0x0010
AlignHorizontal_Mask = AlignLeft | AlignRight | AlignHCenter | AligJustify | AlignAbsolute
AlignTop = 0x0020

setSpacing

1.setHorizontalSpacing(100);
2.setVerticalSpacing(50);
3.setSpacing(8);

#include <QApplication>
#include <QGridLayout>
#include <QPushButton>int main(int argc, char *argv[])
{QApplication a(argc, argv);QWidget *win = new QWidget;QGridLayout *gl =  new QGridLayout(win);QPushButton *but11 = new QPushButton("but11");gl->addWidget(but11,0,0);QPushButton *but12 = new QPushButton("but12");gl->addWidget(but12,0,1);but12->setMinimumSize(100,100);but12->setMaximumSize(500,500);but12->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);QPushButton *but13 = new QPushButton("but13");gl->addWidget(but13,0,2);QPushButton *but21 = new QPushButton("but21");gl->addWidget(but21,1,0);QPushButton *but23 = new QPushButton("but23");gl->addWidget(but23,1,2);//水平间距gl->setHorizontalSpacing(100);//垂直间距gl->setVerticalSpacing(10);win->show();return a.exec();
}

QFormLayout

1.插入项目addRow 和 insertRow
2.遍历项目 
3.表单提交验证示例

QFormLayout addRow

1.QFormLayout *formLayout = new QFormLayout;
2.formLayout->addRow(tr("&Name:"),nameLineEdit);
3.formLayout->addRow(tr("&Email:"),emailLineEdit);
4.formLayout->addRow(tr("&Age:"),ageSpinBox);
5.setLayout(formLayout);

布局器中添加布局器

1.void QFormLayout::addRow(const QString &labelText,QLayout *field);

QFormLayout insertRow

1.void QFormLayout::insertRow
(int row,
const QString &labelText,
QWidget *field)

widget.h

#ifndef WIDGET_H
#define WIDGET_H#include <QWidget>QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACEclass Widget : public QWidget
{Q_OBJECTpublic:Widget(QWidget *parent = nullptr);~Widget();
public slots:void Save();void Clear();
private:Ui::Widget *ui;
};
#endif // WIDGET_H

widget.cpp

#include "widget.h"
#include "ui_widget.h"
#include <QFormLayout>
#include <QLineEdit>
#include <QLabel>
#include <QPushButton>
#include <QDebug>
Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui->setupUi(this);QFormLayout *lay = new QFormLayout(this);QLineEdit *name = new QLineEdit();lay->addRow("&Name",name);QLineEdit *email = new QLineEdit();lay->addRow("&Email",email);QLineEdit *age = new QLineEdit();lay->insertRow(1, "&Age", age);//显示出错信息QLabel *info = new QLabel();info->setText("input");lay->insertRow(0,"",info);//设置样式表info->setStyleSheet("color:red");lay->insertRow(0,"",info);//添加Save 和 Clear按钮QPushButton *save = new QPushButton("Save");QPushButton *clear = new QPushButton("Clear");QObject::connect(save,&QPushButton::clicked,this,&Widget::Save);QObject::connect(clear,&QPushButton::clicked,this,&Widget::Clear);//添加一个平行布局器QHBoxLayout *hlay = new QHBoxLayout();hlay->addWidget(save);hlay->addWidget(clear);lay->addRow(hlay);
}void Widget::Save()
{//找到layoutQFormLayout *lay = (QFormLayout*)this->layout();if(lay == nullptr)return ;//显示错误信息的labelQLabel *label = (QLabel*)lay->itemAt(0,QFormLayout::FieldRole)->widget();//存放错误信息QString error = "";//遍历QFormLayout的所有元素for(int i = 0;i < lay->rowCount();i++){
//        qDebug()<<lay->rowCount()<<" "<<i;QLayoutItem * item = lay->itemAt(i,QFormLayout::FieldRole);QLayoutItem * layItem = lay->itemAt(i,QFormLayout::LabelRole);        if(!item || !layItem) continue;        QLineEdit *e = (QLineEdit*)item->widget();if(!e) continue;QString cname = e->metaObject()->className();QLabel *titleLabel = (QLabel*)layItem->widget();if(!titleLabel) continue;QString title = titleLabel->text();//        qDebug()<<cname;if(cname == "QLineEdit"){if(e->text().trimmed() == ""){e->setFocus();error += title;error += " is empty!\n";}}}//设置错误信息label->setText(error);
}void Widget::Clear()
{//找到layoutQFormLayout *lay = (QFormLayout*)this->layout();if(lay == nullptr)return ;//遍历QFormLayout的所有元素for(int i = 0;i < lay->rowCount();i++){
//        qDebug()<<lay->rowCount()<<" "<<i;QLayoutItem * item = lay->itemAt(i,QFormLayout::FieldRole);if(item == nullptr)continue;QLineEdit *e = (QLineEdit*)item->widget();if(!e)continue;QString cname = e->metaObject()->className();
//        qDebug()<<cname;if(cname == "QLineEdit"){e->setText("");}}
}Widget::~Widget()
{delete ui;
}