1、思维导图
2、练习：优化登录框，输入完用户名和密码后，点击登录，判断账户是否为 Admin 密码 为123456，如果判断成功，则输出登录成功，并关闭整个登录界面，如果登录失败，则提示登录失败，并将账号和密码的行编辑器中的内容清空，账号密码要大于等于五位。
源文件：
#ifndef MYWIDGET_H
#define MYWIDGET_H#include <QWidget>
#include<QIcon> //图标类
#include<QLabel> //标签类
#include<QMovie> //动图类
#include<QLineEdit> //行编辑器类
#include<QPushButton> //按钮类
#include <QDebug> //信息调试类class MyWidget : public QWidget
{Q_OBJECTQPushButton *btn;QLineEdit *edit1;QLineEdit *edit2;QLabel *lab1;QLabel *lab2;QLabel *lab3;QMovie *mv;
public:MyWidget(QWidget *parent = nullptr);~MyWidget();
public slots:void btn_clicked();void edit_changed();
};#endif // MYWIDGET_H头文件：
#include "mywidget.h"MyWidget::MyWidget(QWidget *parent): QWidget(parent)
{this->resize(540,415);this->setFixedSize(540,415);this->setWindowTitle("盗版QQ");this->setWindowIcon(QIcon("D:\\yans\\color\\pictrue\\qq.png"));this->setStyleSheet("background-color:white");this->setWindowFlag(Qt::FramelessWindowHint);this->lab1 = new QLabel(this);lab1->resize(540, 160);lab1->setStyleSheet("background-color:pink");this->mv = new QMovie("D:\\yans\\color\\pictrue\\zz.gif");lab1->setMovie(mv);mv->start();lab1->setScaledContents(true);this->lab2 = new QLabel(this);lab2->resize(30,30);lab2->move(120,210);lab2->setPixmap(QPixmap("D:\\yans\\color\\pictrue\\wodepeizhenshi.png"));lab2->setScaledContents(true);this->lab3 = new QLabel(this);lab3->resize(30,30);lab3->move(120, 260);lab3->setPixmap(QPixmap("D:\\yans\\color\\pictrue\\passwd.jpg"));lab3->setScaledContents(true);this->edit1 = new QLineEdit(this);edit1->resize(275,30);edit1->move(155,210);edit1->setPlaceholderText("QQ号/手机号/邮箱");this->edit2 = new QLineEdit(this);edit2->resize(275,30);edit2->move(155,260);edit2->setPlaceholderText("密码");edit2->setEchoMode(QLineEdit::Password);this->btn = new QPushButton("登录",this);btn->resize(300,45);btn->move(120,345);//样式函数setStyleSheet()btn->setStyleSheet("background-color:yellow;border-radius:5px;color:white");QObject::connect(btn,&QPushButton::clicked,this,&MyWidget::btn_clicked);QObject::connect(btn,&QPushButton::clicked,this,&MyWidget::edit_changed);
}MyWidget::~MyWidget()
{}
void MyWidget::btn_clicked()
{if(this->edit1->text()=="123456"&&this->edit2->text()=="123456"){qDebug()<<"登录成功";this->close();}else {qDebug()<<"登录失败";this->edit1->clear();this->edit2->clear();}
}
void MyWidget::edit_changed()
{if(this->edit1->text().length()>=5&&this->edit2->text().length()>=5){this->btn->setStyleSheet("background-color:blue");}else{this->btn->setStyleSheet("background-color:yellow");}
}
