//界面1 头文件
signals:
    //界面1的自定义信号
    void my_signal();
private slots:
    void on_pushButton_2_clicked();

    void on_pushButton_clicked();
//界面1 .cpp文件
void Widget::on_pushButton_2_clicked()
{
    QMessageBox msg(QMessageBox::Warning,
                    "警告",
                    "是否退出",
                    QMessageBox::Yes| QMessageBox::No,
                    this
                );
    int ret= msg.exec();
    if(ret==QMessageBox::Yes)
    {
        this->close();

    }
    else
    {

    }
}

void Widget::on_pushButton_clicked()
{
    if(ui->lineEdit->text()=="admin"&&ui->lineEdit_2->text()=="123456")
    {
        QMessageBox msg(QMessageBox::Warning,
                        "提示",
                        "登录成功",
                        QMessageBox::Yes,
                        this
                    );
        int ret= msg.exec();
        if(ret==QMessageBox::Yes)
        {
            this->close();
            emit my_signal();
        }
    }
    else
    {
        QMessageBox msg(QMessageBox::Warning,
                        "提示",
                        "账户密码输入错误",
                        QMessageBox::No,
                        this
                    );
        int ret= msg.exec();
        if(ret==QMessageBox::No)
        {

            ui->lineEdit->clear();
            ui->lineEdit_2->clear();

        }
    }
}
//主函数
#include "widget.h"
#include"talk.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    Talk t;
    QObject::connect(&w,&Widget::my_signal,&t,&Talk::my_slot);
    w.show();

    return a.exec();
}