Qt布局简介及其弹簧的使用.

常用的布局有:QVBoxLayout，QHBoxLayout,QGridLayout.分别为垂直布局,水平布局,表格布局.

入门要掌握的概念理解能力是,一定要有容器的概念,这几种布局都相当于容器,容器中能嵌套各种元素(也就是控件)和容器(容器间也能相互包含).

每个容器都是独立的个体,最外边的容器将内元素组成一个整体.<意会意会,重在事务理解,与代码无关>

提前提及这两个函数:这是设置当前容器中各个元素所占据比例的大小的方法.<比如a水平容器有四个元素,分别设置,1,2,1,2则它们所占空间为综合的六分之几>

  bool QBoxLayout::setStretchFactor(QWidget * widget, int stretch)

  bool QBoxLayout::setStretchFactor(QLayout * layout, int stretch)

还需要提及的概念是:布局中弹簧的使用.<适当下增加""隐形元素""占个位置.>,这里注意我的措辞,元素,也就是说弹簧可以被放置到布局中使用.addStretch是带参的,多少个.

增加元素间宽度,函数:addspacing.

直接贴段代码加图就能很好理解了:

Widget::Widget(QWidget *parent)

    : QWidget(parent)

{

    this->resize(QSize(200,300));

    QHBoxLayout *One = new QHBoxLayout;

    QHBoxLayout *Two = new QHBoxLayout;

    QLabel *Id = new QLabel;

    Id->setText("Id:");

    QLineEdit *InputId = new QLineEdit;

    One->addWidget(Id);

    One->addStretch();

    One->addWidget(InputId);

  //  One->setStretchFactor(Id,1);

  //  One->setStretchFactor(InputId,2);

    QLabel *Pass= new QLabel;

    Pass->setText("Pass:");

    QLineEdit *InputPass = new QLineEdit;

    Two->addWidget(Pass);

    Two->addWidget(InputPass);

    Two->addStretch();

    QGridLayout

   // this->setLayout();

    QVBoxLayout *Out = new QVBoxLayout(this);

    Out->addStretch();

    Out->addLayout(One);

    Out->addLayout(Two);

  //  Out->setStretchFactor(One,1);

   // Out->setStretchFactor(One,2);

  //  Out->addStretch();

    QPushButton *Down = new QPushButton;

    Down->setText("Down");

    Out->addWidget(Down);

}

QGridLayout中的addWidge函数:帮助文档中函数原型如下.

void QGridLayout::addLayout(QLayout *layout, int row, int column, int rowSpan, int columnSpan, Qt::Alignment alignment = Qt::Alignment())

备注:你要自己清楚自己写的是什么,也就是过程可控,别瞎乱写,结果当然不可控了.<或者这个函数自己颞部有自处理机制>

表格布局:概念点无非就是,想表格那样中规中矩举,然后就是可能当中元素涉及到跨行或者跨列的<int rowSpan, int columnSpan>.(贴代码加贴图,自己就可以理解了)

第一种:

MainWindow::MainWindow(QWidget *parent)

    : QMainWindow(parent)

{

    QTableView *tableView;

    QStandardItemModel *model;

    QGridLayout *gridLayout;

    QPushButton *button1;

    QPushButton *button2;

    QPushButton *button3;

    QPushButton *button4;

    QWidget *widget;

    gridLayout = new QGridLayout(this);

    button1 = new QPushButton("button1");

    button2 = new QPushButton("button2");

    button3 = new QPushButton("button3");

    button4 = new QPushButton("button4");

    gridLayout->addWidget(button1, 0, 0, 2, 1);

    gridLayout->addWidget(button2, 0, 1, 1, 1);

   // gridLayout->addWidget(button4, 1, 0, 1, 1);

    gridLayout->addWidget(button3, 1, 1, 1, 1);

    QWidget *NewWin = new QWidget;

    NewWin->setLayout(gridLayout);

    NewWin->resize(QSize(200,100));

    this->setCentralWidget(NewWin);

   // this->setLayout(gridLayout);

    this->resize(QSize(400,500));

   // widget->show();

}

第二种:

MainWindow::MainWindow(QWidget *parent)

    : QMainWindow(parent)

{

    QTableView *tableView;

    QStandardItemModel *model;

    QGridLayout *gridLayout;

    QPushButton *button1;

    QPushButton *button2;

    QPushButton *button3;

    QPushButton *button4;

    QWidget *widget;

    gridLayout = new QGridLayout(this);

    button1 = new QPushButton("button1");

    button2 = new QPushButton("button2");

    button3 = new QPushButton("button3");

    button4 = new QPushButton("button4");

    gridLayout->addWidget(button1, 0, 0, 1, 1);

    gridLayout->addWidget(button2, 0, 1, 1, 1);

    gridLayout->addWidget(button4, 1, 0, 1, 1);

    gridLayout->addWidget(button3, 1, 1, 1, 1);

    QWidget *NewWin = new QWidget;

    NewWin->setLayout(gridLayout);

    NewWin->resize(QSize(200,100));

    this->setCentralWidget(NewWin);

   // this->setLayout(gridLayout);

    this->resize(QSize(400,500));

   // widget->show();

}