Qt设计可以控制的布局与控件，coordinate &size 12345

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <iostream>
#include <QDebug>
#include <QBoxLayout>
#include <QGridLayout>
#include <QFormLayout>
#include <QLineEdit>
#include <QStackedLayout>
#include <unistd.h>
#include <QSplitter>
#include <QTextEdit>
#include <QLabel>
#include <QScrollArea>
template<typename Y>
void print_fun(const Y &_y)
{
    qDebug()<<_y;
}

template<class Tag,typename Y>
void print_fun(Tag tg,const Y &_y)
{
#ifdef __cplusplus
    std::cout<<tg<<_y<<std::endl;
#endif
}
#define print_funcpp(var) print_fun("cpp  ",var)


MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{

    ui->setupUi(this);
    //step 1:    QWidget *parent = new QWidget();QWidget::setParent
    QWidget *v_parent = new QWidget();
    v_parent->setGeometry(0,0,500,500);
    v_parent->setParent(ui->centralWidget);

    //step 2:very important*******QBoxLayout(Direction,QWidget*parent) is valid,but QBoxlayout::setParent is invalid**********
    QBoxLayout *vboxlay = new QBoxLayout(QBoxLayout::TopToBottom,v_parent);
    QBoxLayout *hboxlay = new QBoxLayout(QBoxLayout::LeftToRight);

   //step 3:create some QPushButton ......QWidget,QWidget::setParent
    QPushButton *pt = new QPushButton();
    pt->setFixedSize(100,40);
    pt->setText("top");
    pt->setParent(v_parent);

    QPushButton *pb = new QPushButton();
    pb->setFixedSize(100,40);
    pb->setText("bottom");
    pb->setParent(v_parent);

    QPushButton *pc = new QPushButton();
    pc->setFixedSize(100,40);
    pc->setText("center");
    pc->setParent(v_parent);

    QPushButton *pl = new QPushButton();
    pl->setFixedSize(100,40);
    pl->setText("left");
    pl->setParent(v_parent);

    QPushButton *pr = new QPushButton();
    pr->setFixedSize(100,40);
    pr->setText("right");
    pr->setParent(v_parent);

    //step 4:QBoxlayout addWidget
    vboxlay->addWidget(pt,0,Qt::AlignTop|Qt::AlignCenter);
    hboxlay->addWidget(pl,0,Qt::AlignHCenter);
    hboxlay->addWidget(pc,0,Qt::AlignHCenter);
    hboxlay->addWidget(pr,0,Qt::AlignHCenter);
    vboxlay->addLayout(hboxlay);
    vboxlay->addWidget(pb,0,Qt::AlignBottom|Qt::AlignCenter);

    //step 5:QBoxlayout`s parentWidget setLaout(QBoxlayout)
    v_parent->setLayout(vboxlay);

    ///summury
    /// 1\QBoxlayout`s parentWidget-->QWidget::setParent
    /// 2\QBoxlayout-> """""""QBoxlayout`s constructor to setParent""""""""
    /// 3\Widget->QWidget::setParent
    /// 4\QBoxlayout::addWidget
    /// 5\QBoxlayout`s parentWidget setLayout
    /// leran from 3 files:
    /// 1 qt designer page
    /// 2 mainwindow.ui
    /// 3 Ui::MainWindow.h
    /// summury
}

MainWindow::~MainWindow()
{
    delete ui;
}