1> 思维导图

2> 自由发挥应用场景，实现登录界面。

要求：尽量每行代码都有注释。

#include "mywidget.h"

MyWidget::MyWidget(QWidget *parent)
    : QWidget(parent)
{
    //设置标题
    this->setWindowTitle("MYQQ");
    //设置图标
    this->setWindowIcon(QIcon("C:\\Users\\DC\\Desktop\\pictrue\\qq.png"));
    //设置背景颜色
    this->setStyleSheet("background-color:rgb(255,255,255)");
    //固定窗口大小
    this->setFixedSize(540,400);
    //去掉头部
    //this->setWindowFlag(Qt::FramelessWindowHint);

    QLabel *lab1=new QLabel("标签",this);
    lab1->resize(540,400);
    lab1->setStyleSheet("background-color:green");
    QMovie *mv = new QMovie("C:\\Users\\DC\\Desktop\\pictrue\\zz.gif");
    //将动图放入标签中
    lab1->setMovie(mv);
    //让动图动起来
    mv->start();
    //自动适应
    lab1->setScaledContents(true);

    QLabel *lab2=new QLabel("账号",this);
    lab2->resize(40,40);
    lab2->setPixmap(QPixmap("C:\\Users\\DC\\Desktop\\pictrue\\1.png"));
    lab2->move(100,100);
    lab2->setScaledContents(true);

    QLabel *lab3=new QLabel("密码",this);
    lab3->resize(40,40);
    lab3->setPixmap(QPixmap("C:\\Users\\DC\\Desktop\\pictrue\\2.jpg"));
    lab3->move(100,150);
    lab3->setScaledContents(true);

    QLineEdit *edit1=new QLineEdit;
    edit1->setPlaceholderText("QQ号/手机号");
    edit1->setParent(this);
    edit1->resize(260,40);
    edit1->move(150,100);

    QLineEdit *edit2=new QLineEdit("密码",this);
    edit2->setEchoMode(QLineEdit::Password);
    edit2->resize(260,40);
    edit2->move(150,150);

    QPushButton *btn1=new QPushButton("登录",this);
    btn1->resize(120,50);
    btn1->move(210,200);
    //btn1->setEnabled(false);
    //样式函数setStyleSheet()
    btn1->setStyleSheet("background-color:rgb(8,189,253);border-radius:5px;color:white");
}

MyWidget::~MyWidget()
{
}