widget.h
cpp
#ifndef WIDGET_H
#define WIDGET_H
#include <QWidget>
#include <QMessageBox>
QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE
class Widget : public QWidget
{
Q_OBJECT
public:
Widget(QWidget *parent = nullptr);
~Widget();
signals:
void jump();//自定义一个跳转信号
private slots:
void on_loginbtn_clicked();
void on_cancelbtn_clicked();
private:
Ui::Widget *ui;
};
#endif // WIDGET_H
second.h
cpp
#ifndef SECOND_H
#define SECOND_H
#include <QWidget>
namespace Ui {
class second;
}
class second : public QWidget
{
Q_OBJECT
public:
explicit second(QWidget *parent = nullptr);
~second();
public slots:
void jumpSlot(); //对应第一个窗口信号的槽函数声明
private:
Ui::second *ui;
};
#endif // SECOND_H
main.cpp
cpp
#include "widget.h"
#include "second.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Widget w;
w.show();
//实例化第二个窗口的对象
second s;
//将一个窗口的jump信号和第二窗口的jumpSlot槽函数连接
QObject::connect(&w, &Widget::jump, &s, &second::jumpSlot);
return a.exec();
}
widget.cpp
cpp
#include "widget.h"
#include "ui_widget.h"
Widget::Widget(QWidget *parent)
: QWidget(parent)
, ui(new Ui::Widget)
{
ui->setupUi(this);
//窗口的相关设置
this->setWindowTitle("QQ");
this->setWindowIcon(QIcon(":/pictrue/qq.png"));
//标签的相关设置
ui->logolabel->setPixmap(QPixmap(":/pictrue/logo.png"));
ui->logolabel->setScaledContents(true);
//账号和密码
ui->usernamelabel->resize(35,35);
ui->usernamelabel->setPixmap(QPixmap(":/pictrue/userName.jpg"));
ui->usernamelabel->setScaledContents(true);
ui->passwordlabel->resize(35,35);
ui->passwordlabel->setPixmap(QPixmap(":/pictrue/passwd.jpg"));
ui->passwordlabel->setScaledContents(true);
ui->usernamelineEdit->setPlaceholderText("QQ账号/手机号码/邮箱");
// ui->usernamelineEdit->setSizePolicy(QSizePolicy::Preferred,QSizePolicy::Preferred);
// ui->usernamelineEdit->adjustSize();
ui->passwordlineEdit->setEchoMode(QLineEdit::Password);
//登录按钮和取消登录按钮
ui->loginbtn->setIcon(QIcon(":/pictrue/login.png"));
ui->cancelbtn->setIcon(QIcon(":/pictrue/cancel.png"));
//qt5版本 判断账号是否为admin,密码是否为123456
connect(ui->loginbtn,&QPushButton::clicked,this,&Widget::on_loginbtn_clicked);
}
Widget::~Widget()
{
delete ui;
}
//登录按钮对应的槽函数
void Widget::on_loginbtn_clicked()
{
if(ui->usernamelineEdit->text()=="admin" && ui->passwordlineEdit->text()=="123456")
{
QMessageBox msg(
QMessageBox::Information,//图标
"信息对话框", //消息对话框标题
"登录成功", //对话框文本
QMessageBox::Ok, //提供OK按钮
this); //父对象
//用exec()函数执行对话框
int ret = msg.exec();
//对用户选中的按钮进行判断
if(ret == QMessageBox::Ok)
{
this->close();
emit jump();
}
}
else
{
QMessageBox msg(
QMessageBox::Critical, //错误图标
"错误对话框", //错误对话框标题
"账号和密码不匹配", //错误对话框文本
QMessageBox::Yes | QMessageBox::No, //提供Yes/No按钮
this); //父对象
//用exec()函数执行对话框
int ret = msg.exec();
//对用户选中的按钮进行判断
if(ret == QMessageBox::Yes)
{
//清除密码框中的内容
ui->passwordlineEdit->setText("");
}
else if(ret == QMessageBox::No)
{
//关闭登录
this->close();
}
}
}
//取消登录按钮对应的槽函数
void Widget::on_cancelbtn_clicked()
{
//直接调用静态成员函数
int ret = QMessageBox::question(this,
"问题对话框",
"您是否确定要退出登录?",
QMessageBox::Yes | QMessageBox::No);
//对用户选中的按钮进行判断
if(ret == QMessageBox::Yes)
{
this->close();
}
else if(ret == QMessageBox::No)
{
}
}
second.cpp
cpp
#include "second.h"
#include "ui_second.h"
second::second(QWidget *parent) :
QWidget(parent),
ui(new Ui::second)
{
ui->setupUi(this);
}
second::~second()
{
delete ui;
}
void second::jumpSlot()
{
this->show();
}