qt部分核心机制

作业

1> 手动将登录项目实现，不要使用拖拽编程

并且，当点击登录按钮时，后台会判断账号和密码是否相等，如果相等给出登录成功的提示，并且关闭当前界面，发射一个跳转信号，如果登录失败，则给出登录失败的提示，并清空密码框

当点击取消按钮时，直接关闭当前登录框

.h文件

#ifndef MYJOB_H
#define MYJOB_H#include <QMainWindow>
#include <QPushButton>
#include <QLabel>
#include <QWidget>
#include<QLineEdit>
#include <QObject>
#include <QMessageBox>
class myjob : public QMainWindow
{Q_OBJECTsignals:void my_signal();       //定义一个信号函数
public slots:void  btn1_yes_slot();      //自定义槽函数void  btn2_no_slot();
private slots:void  showMessage(){QMessageBox::information(this,"Information","登录失败！");}
public:myjob(QWidget *parent = nullptr);~myjob();
private:QLabel *btn1_Account_label;QLabel *btnlogo_Icon_label;QLabel *btn2_Cryptographic_tag_label;QLineEdit *btn1_Account_entry;QLineEdit *btn2_Password_input;QPushButton *btn1_yes;QPushButton *btn2_no;
};
#endif // MYJOB_H

 源码文件

#include "myjob.h"myjob::myjob(QWidget *parent): QMainWindow(parent)
{//主页面设置this->setFixedSize(400,600);      //主页面大小//logo图标(也是标签)this->btnlogo_Icon_label = new QLabel;btnlogo_Icon_label->setParent(this);    //设置父组件btnlogo_Icon_label->resize(400,150);      //设置标签宽高btnlogo_Icon_label->move(0,0);      //移动标签位置btnlogo_Icon_label->setText("霜雪阅读");     //设置文本btnlogo_Icon_label->setStyleSheet("background-color:green;");     //设置背景颜色，否则看不见btnlogo_Icon_label->setAlignment(Qt::AlignCenter);        //设置对齐方式//账户标签btn1_Account_label = new QLabel;        //无参构造btn1_Account_label->setParent(this);    //设置父组件btn1_Account_label->resize(50,20);      //设置标签宽高btn1_Account_label->move(50,200);      //移动标签位置btn1_Account_label->setText("账户");     //设置文本btn1_Account_label->setStyleSheet("background-color:red;");     //设置背景颜色，否则看不见btn1_Account_label->setAlignment(Qt::AlignCenter);        //设置对齐方式//账户输入btn1_Account_entry = new QLineEdit(this);     //有参构造并设置父组件btn1_Account_entry->resize(150,20);         //设置宽和高btn1_Account_entry->move(btn1_Account_label->x()+btn1_Account_label->width()+10, btn1_Account_label->y());//btn1_Account_entry->setStyleSheet("background-color:pick;");     //设置背景颜色，否则看不见btn1_Account_entry->setAlignment(Qt::AlignCenter);        //设置对齐方式btn1_Account_entry->setPlaceholderText("请输入账号");      //设置占位文本//密码标签btn2_Cryptographic_tag_label = new QLabel;btn2_Cryptographic_tag_label->setParent(this);    //设置父组件btn2_Cryptographic_tag_label->resize(50,20);      //设置标签宽高btn2_Cryptographic_tag_label->move(btn1_Account_label->x(),btn1_Account_label->y()+btn1_Account_label->height()+15);      //移动标签位置btn2_Cryptographic_tag_label->setText("密码");     //设置文本btn2_Cryptographic_tag_label->setStyleSheet("background-color:red;");     //设置背景颜色，否则看不见btn2_Cryptographic_tag_label->setAlignment(Qt::AlignCenter);        //设置对齐方式//密码输入btn2_Password_input = new QLineEdit(this);     //有参构造并设置父组件btn2_Password_input->resize(150,20);         //设置宽和高btn2_Password_input->move(btn2_Cryptographic_tag_label->x()+btn2_Cryptographic_tag_label->width()+10, btn2_Cryptographic_tag_label->y());//btn2_Password_input->setStyleSheet("background-color:pick;");     //设置背景颜色，否则看不见btn2_Password_input->setAlignment(Qt::AlignCenter);        //设置对齐方式btn2_Password_input->setPlaceholderText("请输入密码");      //设置占位文本btn2_Password_input->setEchoMode(QLineEdit::Password);      //设置密文//登录按钮btn1_yes = new QPushButton("确认",this);  //有参构造并设置父组件及填充文本btn1_yes->resize(50,35);        //设置按键的宽和高btn1_yes->move(btn2_Cryptographic_tag_label->x()+btn2_Cryptographic_tag_label->x(),btn2_Cryptographic_tag_label->y()+200);//取消按钮btn2_no = new QPushButton("取消",this);  //有参构造并设置父组件及填充文本btn2_no->resize(50,35);        //设置按键的宽和高btn2_no->move(btn1_yes->x()+100,btn1_yes->y());//连接登录按钮QObject::connect(this->btn1_yes,&QPushButton::clicked(,this,&Mainlogin::btn1_yes_slot));//连接取消按钮
}myjob::~myjob()
{
}

 测试文件

#include "myjob.h"#include <QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);myjob w;w.show();return a.exec();
}

2> 思维导图

3>两篇刷题28/30