QT--day1

登陆界面

#include "mainwindow.h"
#include "ui_mainwindow.h"
 
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    //设置固定大小
    this->setFixedSize(400,300);
    //设置窗口标题
    this->setWindowTitle("HUAQI");
    //设置窗口图标
    this->setWindowIcon(QIcon("D:\\Qt\\icon\\icon\\wodepeizhenshi.png"));
    //构建两个按钮
    QPushButton *btn1=new QPushButton(QIcon("D:\\Qt\\icon\\icon\\login.png"),"登录",this);
    btn1->resize(100,40);
    btn1->move(100,250);
    QPushButton *btn2=new QPushButton(QIcon("D:\\Qt\\icon\\icon\\cancel.png"),"取消",this);
    btn2->resize(btn1->size());
    btn2->move(btn1->x()+150,btn1->y());
    //构建两个行编辑器
    QLineEdit *edit1=new QLineEdit(this);
    edit1->resize(200,30);
    edit1->setEchoMode(QLineEdit::Password);
    edit1->setText("123456");
    edit1->move(125,btn1->y()-50);
    QLineEdit *edit2=new QLineEdit(this);
    edit2->resize(200,30);
    edit2->setText("admin");
    edit2->move(125,edit1->y()-50);
    //构建三个标签
    QLabel *lab1=new QLabel(this);
    lab1->resize(30,30);
    lab1->setPixmap(QPixmap("D:\\Qt\\icon\\icon\\passwd.jpg"));
    lab1->setScaledContents(true);
    lab1->move(edit1->x()-40,edit1->y());
 
    QLabel *lab2=new QLabel(this);
    lab2->resize(lab1->size());
    lab2->setPixmap(QPixmap("D:\\Qt\\icon\\icon\\userName.jpg"));
    lab2->setScaledContents(true);
    lab2->move(edit2->x()-40,edit2->y());
 
    QLabel *lab3=new QLabel(this);
    lab3->resize(400,120);
    lab3->setPixmap(QPixmap("D:\\Qt\\icon\\icon\\logo.png"));
    lab3->setScaledContents(true);
}
 
MainWindow::~MainWindow()
{
    delete ui;
}

将工程文件进行注释

1.工程管理文件

QT       += core gui
#引入QT所需要的库，core是核心库，gui是图形开发相关类的库
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
#超过4。0版本的，加上widgets库
CONFIG += c++11
#支持C++11版本的
# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS
 
# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
#对源文件进行管理
SOURCES += \
    main.cpp \
    mywnd.cpp
#对头文件进行管理
HEADERS += \
    mywnd.h
#对UI文件进行管理
FORMS += \
    mywnd.ui
 
# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

2.头文件

#ifndef MYWND_H
#define MYWND_H
//防止头文件重复包含
 
//父类的头文件
#include <QWidget>
 
QT_BEGIN_NAMESPACE
//声明UI文件对应的命名空间
namespace Ui { class MyWnd; }
QT_END_NAMESPACE
//公共继承QWidget
class MyWnd : public QWidget
{
    //信号和槽的元对象，没有元对象，信号和槽就不能使用
    Q_OBJECT
 
public:
    //构造函数，带有一个默认变量
    MyWnd(QWidget *parent = nullptr);
    ~MyWnd();
 
private:
    //可以使用UI指针调用Ui界面中的组件
    Ui::MyWnd *ui;
};
#endif // MYWND_H

3.源文件

#include "mywnd.h"
#include "ui_mywnd.h"
 
MyWnd::MyWnd(QWidget *parent)
    //先行调用父类有参构造函数
    : QWidget(parent)
    //给自己类中的Ui指针舒适化空间
    , ui(new Ui::MyWnd)
{
    //调用Ui
    ui->setupUi(this);
}
 
MyWnd::~MyWnd()
{
    //释放指针空间
    delete ui;
}
 

4.主程序文件

#include "mywnd.h"
//引入应用程序的头文件
#include 
 
int main(int argc, char *argv[])
{
    //实例化一个应用程序对象
    QApplication a(argc, argv);
    //实例化自定义的图形化界面的类
    MyWnd w;
    //展示界面
    w.show();
    //阻塞等待应用程序，等待用户操作
    return a.exec();
}