8.31 qt

 手动实现对象树模型:

#include <iostream>
#include<list>

using namespace std;

class ObjTree
{
private:
    list<ObjTree *> childList;       //存放子对象的指针链表
public:
    ObjTree(ObjTree *parent = nullptr) {
        if(parent != nullptr)
        parent->childList.push_back(this);
    }

    virtual ~ObjTree()
    {
        for (auto it=childList.begin(); it!=childList.end(); ++it) {
            delete *it;
        }
    }

    list<ObjTree *> & child()
    {
        return childList;
    }
};

//定义子类
class A:public ObjTree
{
public:
    A(ObjTree *parent = nullptr)
    {
        if(parent != nullptr)
        {
            parent->child().push_back(this);

        }
        cout<<"A::构造函数"<<endl;
    }

    virtual ~A()
    {
        cout<<"A::析构函数"<<endl;
    }
};

class B:public ObjTree
{
public:
    B(ObjTree *parent = nullptr)
    {
        if(parent != nullptr)
        {
            parent->child().push_back(this);

        }
        cout<<"B::构造函数"<<endl;
    }

    virtual ~B()
    {
        cout<<"B::析构函数"<<endl;
    }
};


int main()
{

    cout<<"================"<<endl;
    B b;           //实例化b这个控件
    A *a = new A( &b );   //此时a依附于b

    return 0;
}

创建一个项目，提供三个按钮，第一个按钮实现播报第二个按钮的内容，播报结束后，设置自己不可用。第二个按钮的内容是关闭，实现功能是关掉整个项目，第三个按钮功能是将第一个按钮设置为可以状态

 wigget.cpp:

#include "widget.h"
#include<QDebug>
#include <QTextToSpeech>
//#include "ui_widget.h"
Widget::Widget(QWidget *parent)
    : QWidget(parent)
    //, ui(new Ui::Widget)
{
    this->resize (1024,768);
    this->setMaximumSize (1500,1000);
    this->setMinimumSize (500,200);

    //设置窗口标题
    this->setWindowTitle ("我的窗口");
    //获取标题
    QString title = this->windowTitle ();
    qDebug()<<title;

    //设置背景颜色
    this->setBackgroundRole (QPalette::Mid);
    //设置允许改变背景
    this->setAutoFillBackground (true);

    btnl = new QPushButton(" 显示",this);
    btnl->resize(100,50);
    // btnl->move(200,200);
    btnl->move (width ()/2,height ()/2);

    btnl1 = new QPushButton("关闭",this);
    btnl1->resize(100,50);
    btnl1->move(btnl->width ()+width()/2,height ()/2);

    btnl2 = new QPushButton("复用",this);
    btnl2->resize(100,50);
    btnl2->move(btnl->width ()+width()/2+btnl1->width (),height ()/2);



    //qt4版本的连接
    //connect (btnl,SIGNAL (clicked()),this,SLOT(showmsg()));

    //lamda 表达式
    /*
    connect(btnl2,&QPushButton::clicked ,[&]()
    {
        emit signal_1();
    });

    connect (this,&Widget::signal_1,this,&Widget::say_msg);

    */
    //qt5版本的connect连接
    connect(btnl,&QPushButton::clicked,this,&Widget::say_msg );

    connect (btnl1,&QPushButton::clicked ,this,&Widget::close_msg);

    connect (btnl2,&QPushButton::clicked,this,&Widget::reuse_msg );
    /*
    connect(btnl,&QPushButton::clicked ,[&]()
    {
        btnl2->setText ("abcdefghijklmn");
    });
    */

    //移动位置
    // this->move(500,50);
    //输出宽度和高度
    qDebug()<<"width = "<<this->width ()<<"   height = "<<this->height ();

    //输出坐标点
    qDebug()<<"坐标点为:"<<this->x()<<","<<this->y ();
    //ui->setupUi(this);

}

Widget::~Widget()
{
    //delete ui;
}

void Widget::showmsg()
{
    static int i = 1;
    this->btnl2->setText(QString::number (i++));
    // this->btnl1->setText("111111");
    speech.say(btnl2->text ());
    btnl1->setEnabled (false);
}

void Widget::say_msg()
{
    speech.say(btnl1->text());
    btnl->setEnabled (false);
}

void Widget::close_msg()
{
    close ();
}

void Widget::reuse_msg()
{
    btnl->setEnabled (true);
}