1.

#include "widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    this->resize(540,415);
      this->setFixedSize(540,415);
      //窗口标题
      this->setWindowTitle("盗版QQ");
      //窗口图标
      this->setWindowIcon(QIcon("E:\\qq\\pictrue\\pictrue\\qq.png"));
      //背景颜色
      this->setStyleSheet("background-color:white");



      //============标签相关设置=======
      QLabel *lab1 = new QLabel(this);
      //设置大小
      lab1->resize(540, 160);
      lab1->setStyleSheet("background-color:pink");
      //动图类 接收动图
      QMovie *mv = new QMovie("E:\\qq\\pictrue\\pictrue\\zz.gif");
      //将动图放入标签中
      lab1->setMovie(mv);
      //让动图动起来
      mv->start();
      //自动适应
      lab1->setScaledContents(true);


      QLabel *lab2 = new QLabel(this);
      lab2->resize(30,30);
      lab2->move(120,210);
      lab2->setPixmap(QPixmap("E:\\qq\\pictrue\\pictrue\\wodepeizhenshi.png"));
      lab2->setScaledContents(true);


      QLabel *lab3 = new QLabel(this);
      lab3->resize(30,30);
      lab3->move(120, 260);
      lab3->setPixmap(QPixmap("E:\\qq\\pictrue\\pictrue\\passwd.jpg"));
      lab3->setScaledContents(true);


      //============行编辑器相关设置=======
      edit3 = new QLineEdit(this);
      edit3->resize(275,30);
      edit3->move(155,210);
      edit3->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);




      //============按钮相关设置=======
      QPushButton *btn = new QPushButton("登录",this);
      btn->resize(300,45);
      btn->move(120,345);
        connect(btn,&QPushButton::clicked,this,&Widget::btn1_clicked);

}


void Widget::btn1_clicked()
{

    if(this->edit3->text() == "Admin" && this->edit2->text() == "123456")

   {
             QMessageBox box(QMessageBox::Question,
                    "信息对话框",
                    "登录成功",
                    QMessageBox::Ok,
                    this);
             int res1 = box.exec();
             if(res1 == QMessageBox::Ok)
                {

                 emit jump();

              this->close();
}
}else
        {
QMessageBox box(QMessageBox::Critical,
       "错误对话框",
       "登录失败，是否重新登录",
       QMessageBox::Ok|QMessageBox::No,
       this);
   // box.setButtonText(QMessageBox::Ok,"yes");
   // box.setButtonText(QMessageBox::No,"no");
       int res = box.exec();
       if(res == QMessageBox::Ok)
       {
           this->edit2->clear();
           this->edit3->clear();
       }else if(res == QMessageBox::No)
       {

           this->close();
       }

}
}
Widget::~Widget()
{
}

2.

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
}

Widget::~Widget()
{
    delete ui;
}


void Widget::on_pushButton_clicked()
{
    bool ok = false;
    QFont f = QFontDialog::getFont(&ok,
                                   QFont("宋体",10,10,true),
                                    this,
                                     "选择字体");
    if(ok)
    {
        ui->textEdit->setCurrentFont(f);
    }
}

void Widget::on_pushButton_2_clicked()
{
    QColor c = QColorDialog::getColor(QColor("red"),
                                      this,
                                      "选择颜色");
    if(c.isValid() == true)
    {
        ui->textEdit->setTextColor(c);
    }
}

void Widget::on_pushButton_3_clicked()
{
    QString fileName = QFileDialog::getOpenFileName(this,
                                                "选择文件",
                                              "./",
                                                "all(*.*);;images(*.png *.jpg *.gif);;源文件(*.cpp)");
 qDebug() << fileName;
 QFile file(fileName);
 if(file.open(QFile::ReadOnly) == false)
 {
     QMessageBox::information(this,"提示","文件打开失败");
     return;
 }
 QByteArray msg = file.readAll();
 ui->textEdit->setText(msg);
 file.close();
}



void Widget::on_pushButton_4_clicked()
{
    QString fileName = QFileDialog::getSaveFileName(this,
                                                "选择文件",
                                              "./",
                                                "all(*.*);;images(*.png *.jpg *.gif);;源文件(*.cpp)");
    QFile file(fileName);

       //打开文件
       if(!file.open(QFile::WriteOnly))
       {
           return;
       }

       //获取textEdit中的内容
       QString msg = ui->textEdit->toPlainText();

       //将textEdit中的内容写入到filename中
       file.write(msg.toLocal8Bit());

       //关闭文件
       file.close();

}