头文件

#ifndef MYWIDGET_H
#define MYWIDGET_H#include <QWidget>
#include <QDebug>
#include<QIcon>
#include<QLabel>
#include<QMovie>
#include<QLineEdit>
#include<QPushButton>
QT_BEGIN_NAMESPACE
namespace Ui { class MyWidget; }
QT_END_NAMESPACEclass MyWidget : public QWidget
{Q_OBJECTpublic:MyWidget(QWidget *parent = nullptr);~MyWidget();
public slots:void edit_Slots();void btn_Slots();private:Ui::MyWidget *ui;QLabel *lab1;QLabel *lab2;QLabel *lab3;QLineEdit *edit1;QLineEdit *edit2;QPushButton *btn;
};
#endif // MYWIDGET_H

源文件

#include "mywidget.h"
#include "ui_mywidget.h"MyWidget::MyWidget(QWidget *parent): QWidget(parent), ui(new Ui::MyWidget)
{ui->setupUi(this);//设置窗口大小this->resize(540,415);//固定窗口大小this->setFixedSize(540,415);//设置标题this->setWindowTitle("QQ");//设置图标this->setWindowIcon(QIcon("D:\\QT\\pictrue\\pictrue\\qq.png"));//图标颜色this->setStyleSheet("background-color:white");//设置标签    lab1 = new QLabel(this);//设置标签大小lab1->resize(540, 160);//接收动图QMovie *mv = new QMovie("D:QT\\pictrue\\pictrue\\qq2.gif");//将动图放入标签lab1->setMovie(mv);//让动图动起来mv->start();//自动适应大小lab1->setScaledContents(true);//设置标签2lab2 = new QLabel(this);//标签大小lab2->resize(30,30);//标签移动位置lab2->move(120,210);//将图片放入标签lab2->setPixmap(QPixmap("D:QT\\pictrue\\pictrue\\wodepeizhenshi.png"));//自动适应大小lab2->setScaledContents(true);//设置标签lab3 = new QLabel(this);lab3->resize(30,30);lab3->move(120, 260);lab3->setPixmap(QPixmap("D:QT\\pictrue\\pictrue\\passwd.jpg"));lab3->setScaledContents(true);//设置行编辑器edit1 = new QLineEdit(this);//行编辑器大小edit1->resize(275,30);//移动行编辑器位置edit1->move(155,210);//行编辑器占位edit1->setPlaceholderText("QQ号/手机号/邮箱");edit2 = new QLineEdit(this);edit2->resize(275,30);edit2->move(155,260);edit2->setPlaceholderText("密码");edit2->setEchoMode(QLineEdit::Password);//按钮组件btn = new QPushButton("登录",this);//按钮组件大小btn->resize(300,45);//按钮组件移动位置btn->move(120,345);//按钮背景色，边框倒角，字体颜色btn->setStyleSheet("background-color:red;border-radius:5px;color:white");btn->setEnabled(false);connect(this->edit1,&QLineEdit::textChanged,this,&MyWidget::edit_Slots);connect(this->edit2,&QLineEdit::textChanged,this,&MyWidget::edit_Slots);connect(this->btn,&QPushButton::clicked,this,&MyWidget::btn_Slots);}void MyWidget::btn_Slots()
{if(this->edit1->text()=="admin" && this->edit2->text()=="123456"){qDebug() << "登录成功";this->close();}else{qDebug() << "登录失败，账号或密码错误";this->edit1->clear();this->edit2->clear();}
}
void MyWidget::edit_Slots()
{QString s1=this->edit1->text();QString s2=this->edit2->text();if(s1.length()>=5 && s2.length()>=6 ){this->btn->setStyleSheet("background-color:rgb(125,18,179)");this->btn->setEnabled(true);}else if(s1.length()<5 || s2.length()<6  ){this->btn->setStyleSheet("background-color:red");this->btn->setEnabled(false);}}MyWidget::~MyWidget()
{delete ui;
}