qt作业day2

1：在注册登录的练习里面，追加一个QListWidget 项目列表 要求：点击注册之后，将账号显示到 listWidget上面去 以及，在listWidget中双击某个账号的时候，将该账号删除

.h

#ifndef WIDGET_H
#define WIDGET_H
#include "QFile"
#include <QWidget>
#include <QListWidget>QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACEclass Widget : public QWidget
{Q_OBJECTpublic:Widget(QWidget *parent = nullptr);void save_data(const QString &filename,const QString &data);QString load_data(const QString& filename);~Widget();private slots:void on_lineEdit_2_textChanged(const QString &arg1);void on_lineEdit_textChanged(const QString &arg1);void on_pushButton_3_pressed();void on_pushButton_3_released();void on_checkBox_stateChanged(int arg1);void on_pushButton_clicked();  // 注册按钮点击void on_lineEdit_returnPressed();  // 输入框回车void myslot_2();  // 信号示例void loadAccountInfo();  // 加载账号信息void deleteAccount(QListWidgetItem* item);  // 删除账号private:Ui::Widget *ui;QFile file;QString accountFilePath;  // 账号信息文件路径QList<QString> accounts;  // 存储账号信息
};
#endif // WIDGET_H

.cpp

#include "widget.h"
#include "ui_widget.h"
#include "QFile"Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui->setupUi(this);QString name = load_data("F:/hqyjian/mm.txt");ui->lineEdit->setText(name);accountFilePath = "F:/hqyjian/mm.txt";// 加载账号信息loadAccountInfo();// 连接信号和槽connect(ui->pushButton, &QPushButton::clicked, this, &Widget::on_pushButton_clicked);connect(ui->lineEdit_2, &QLineEdit::returnPressed, this, &Widget::on_lineEdit_returnPressed);connect(ui->listWidget, &QListWidget::itemDoubleClicked, this, &Widget::deleteAccount);
}Widget::~Widget()
{QString name = ui->lineEdit_2->text();QString password = ui->lineEdit->text();save_data("F:/hqyjian/mm.txt",name);save_data("F:/hqyjian/mm.txt",password);delete ui;
}void Widget::save_data(const QString &filename,const QString &data)
{file.setFileName(filename);file.open(QFile::WriteOnly);file.write(data.toLocal8Bit());file.close();
}QString Widget::load_data(const QString &filename)
{file.setFileName(filename);file.open(QFile::ReadOnly);QByteArray arr = file.readAll();QString str = QString::fromLocal8Bit(arr);file.close();return str;
}void Widget::on_lineEdit_2_textChanged(const QString &arg1)
{QString name = ui->lineEdit->text();QString pswd = ui->lineEdit_2->text();if(name.isEmpty() || pswd.isEmpty()){ui->pushButton->setEnabled(0);ui->pushButton_2->setEnabled(0);}else{ui->pushButton->setEnabled(1);ui->pushButton_2->setEnabled(1);}
}void Widget::on_lineEdit_textChanged(const QString &arg1)
{QString name = ui->lineEdit->text();QString pswd = ui->lineEdit_2->text();if(name.isEmpty() || pswd.isEmpty()){ui->pushButton->setEnabled(0);ui->pushButton_2->setEnabled(0);}else{ui->pushButton->setEnabled(1);
}
}void Widget::on_pushButton_3_pressed()
{ui->lineEdit->setEchoMode(QLineEdit::Normal);}void Widget::on_pushButton_3_released()
{ui->lineEdit->setEchoMode(QLineEdit::Password);}void Widget::on_checkBox_stateChanged(int arg1)
{}
void Widget::on_pushButton_clicked()
{QString str = ui->lineEdit->text();if (!str.isEmpty()) {accounts.append(str);ui->listWidget->addItem(str);  // 添加到 QListWidgetui->textEdit->append(str);  // 添加到 QTextEditui->lineEdit->clear();}
}void Widget::on_lineEdit_returnPressed()
{on_pushButton_clicked();  // 回车键触发注册按钮点击事件
}void Widget::myslot_2()
{ui->textEdit->append("dda");
}void Widget::loadAccountInfo()
{QFile file(accountFilePath);if (file.open(QIODevice::ReadOnly | QIODevice::Text)) {QTextStream in(&file);while (!in.atEnd()) {QString line = in.readLine();accounts.append(line);ui->listWidget->addItem(line);  // 添加到 QListWidgetui->textEdit->append(line);  // 添加到 QTextEdit}file.close();}
}void Widget::deleteAccount(QListWidgetItem* item)
{if (item) {QString account = item->text();accounts.removeAll(account);ui->listWidget->removeItemWidget(item);delete item;// 保存更新后的账号信息QFile file(accountFilePath);if (file.open(QIODevice::WriteOnly | QIODevice::Text)) {QTextStream out(&file);for (const QString& acc : accounts) {out << acc << "\n";}file.close();}}
}

main.cpp

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

2.完成一个计算器，ui界面如下 完成 +-*/计算功能并且在对应位置显示对应的数据

.h

#ifndef WIDGET_H
#define WIDGET_H#include <QWidget>
#include "QString"
#include "QIcon"
#include "math.h"
#include "QPixmap"
#include <QPainter>namespace Ui {
class Widget;
}class Widget : public QWidget
{Q_OBJECTpublic:explicit Widget(QWidget *parent = 0);~Widget();void paintEvent(QPaintEvent *event);
public slots:void push_Botton();void push_Botton1();void push_Botton2();void push_Botton3();void push_Botton4();void push_Botton5();void push_Botton6();void push_Botton7();void push_Botton8();void push_Botton9();void bnt_add();void bnt_sub();void bnt_mul();void bnt_div();void bnt_d();void bnt_over();private slots:void on_clear_clicked(bool checked);void on_clearall_clicked(bool checked);void on_delete_2_clicked(bool checked);void on_fenshu_clicked(bool checked);void on_pow_clicked(bool checked);void on_genhao_clicked(bool checked);void on_aors_clicked(bool checked);void on_yu_clicked(bool checked);private:Ui::Widget *ui;QString symbol = "";QString num1 = "";QString num2 = "";QString over = "";QString msg = "";bool isSave01 = true;bool isSave02 = true;
};#endif // WIDGET_H

.cpp

#include "widget.h"
#include "QIcon"
#include "QString"
#include "QDebug"
#include "QLabel"
Widget::Widget(QWidget *parent) :QWidget(parent),ui(new Ui::Widget)
{ui->setupUi(this);this->setFixedSize(430,550);this->setWindowTitle("计算器");this->setWindowIcon(QIcon(":/image/computer.webp"));//使用setStyleSheet方法设置标签颜色ui->label_msg->setStyleSheet("QLabel { color: grey; }");connect(ui->add,SIGNAL(clicked(bool)),this,SLOT(bnt_add()));connect(ui->div,SIGNAL(clicked(bool)),this,SLOT(bnt_div()));connect(ui->sub,SIGNAL(clicked(bool)),this,SLOT(bnt_sub()));connect(ui->mul,SIGNAL(clicked(bool)),this,SLOT(bnt_mul()));connect(ui->over,SIGNAL(clicked(bool)),this,SLOT(bnt_over()));connect(ui->btn_d,SIGNAL(clicked(bool)),this,SLOT(bnt_d()));connect(ui->push_Botton_0,SIGNAL(clicked(bool)),this,SLOT(bnt_num0()));connect(ui->push_Botton_1,SIGNAL(clicked(bool)),this,SLOT(bnt_num1()));connect(ui->push_Botton_2,SIGNAL(clicked(bool)),this,SLOT(bnt_num2()));connect(ui->push_Botton_3,SIGNAL(clicked(bool)),this,SLOT(bnt_num3()));connect(ui->push_Botton_4,SIGNAL(clicked(bool)),this,SLOT(bnt_num4()));connect(ui->push_Botton_5,SIGNAL(clicked(bool)),this,SLOT(bnt_num5()));connect(ui->push_Botton_6,SIGNAL(clicked(bool)),this,SLOT(bnt_num6()));connect(ui->push_Botton_7,SIGNAL(clicked(bool)),this,SLOT(bnt_num7()));connect(ui->push_Botton_8,SIGNAL(clicked(bool)),this,SLOT(bnt_num8()));connect(ui->push_Botton_9,SIGNAL(clicked(bool)),this,SLOT(bnt_num9()));}Widget::~Widget()
{delete ui;
}void Widget::paintEvent(QPaintEvent *event)
{QPainter painter(this);
//    painter.drawPixmap(0,0,width(),height(),QPixmap(":/image/bizhi.jpg"));
}
//数字0代码段
void Widget::bnt_num0()
{if(symbol == ""){if(num1 == "0"){num1.chop(1);}num1.append("0");ui->label_idet->setText(num1);}else{if(num2 == "0"){num2.chop(1);}num2.append("0");ui->label_idet->setText(num2);}
}
//数字1代码段
void Widget::bnt_num1()
{if(symbol == ""){if(num1 == "0"){num1.chop(1);}num1.append("1");ui->label_idet->setText(num1);}else{if(num2 == "0"){num2.chop(1);}num2.append("1");ui->label_idet->setText(num2);}
}
//数字2代码段
void Widget::bnt_num2()
{if(symbol == ""){if(num1 == "0"){num1.chop(1);}num1.append("2");ui->label_idet->setText(num1);}else{if(num2 == "0"){num2.chop(1);}num2.append("2");ui->label_idet->setText(num2);}
}
//数字3代码段
void Widget::bnt_num3()
{if(symbol == ""){if(num1 == "0"){num1.chop(1);}num1.append("3");ui->label_idet->setText(num1);}else{if(num2 == "0"){num2.chop(1);}num2.append("3");ui->label_idet->setText(num2);}
}
//数字4代码段
void Widget::bnt_num4()
{if(symbol == ""){if(num1 == "0"){num1.chop(1);}num1.append("4");ui->label_idet->setText(num1);}else{if(num2 == "0"){num2.chop(1);}num2.append("4");ui->label_idet->setText(num2);}
}
//数字5代码段
void Widget::bnt_num5()
{if(symbol == ""){if(num1 == "0"){num1.chop(1);}num1.append("5");ui->label_idet->setText(num1);}else{if(num2 == "0"){num2.chop(1);}num2.append("5");ui->label_idet->setText(num2);}
}
//数字6代码段
void Widget::bnt_num6()
{if(symbol == ""){if(num1 == "0"){num1.chop(1);}num1.append("6");ui->label_idet->setText(num1);}else{if(num2 == "0"){num2.chop(1);}num2.append("6");ui->label_idet->setText(num2);}
}
//数字7代码段
void Widget::bnt_num7()
{if(symbol == ""){if(num1 == "0"){num1.chop(1);}num1.append("7");ui->label_idet->setText(num1);}else{if(num2 == "0"){num2.chop(1);}num2.append("7");ui->label_idet->setText(num2);}
}
//数字8代码段
void Widget::bnt_num8()
{if(symbol == ""){if(num1 == "0"){num1.chop(1);}num1.append("8");ui->label_idet->setText(num1);}else{if(num2 == "0"){num2.chop(1);}num2.append("8");ui->label_idet->setText(num2);}
}
//数字9代码段
void Widget::bnt_num9()
{if(symbol == ""){if(num1 == "0"){num1.chop(1);}num1.append("9");ui->label_idet->setText(num1);}else{if(num2 == "0"){num2.chop(1);}num2.append("9");ui->label_idet->setText(num2);}
}
//小数点代码段
void Widget::bnt_d()
{if(symbol == ""){num1.append(".");ui->label_idet->setText(num1);}else{num2.append(".");ui->label_idet->setText(num2);}
}//加法
void Widget::bnt_add()
{double n1 = num1.toDouble();double n2 = num2.toDouble();double x = 0.0;if(symbol == "+"){//计算三位以上的式子x = n1 + n2;num1 = QString::number(x);qDebug()<<"x="<<x;}else if (symbol =="-"){x = n1 - n2;num1 = QString::number(x);}else if (symbol =="×"){x = n1 * n2;num1 = QString::number(x);}else if (symbol =="÷"){x = n1 / n2;num1 = QString::number(x);}else if(symbol == "%"){if(num1 == ""){ui->label_msg->setText("0");}else if(num2 != ""){num1 = QString::number(x);}}num2 = "";msg = "";//将式子放入信息栏中if(isSave01){msg.append(num1);}symbol = "+";msg.append(symbol);ui->label_msg->setText(msg);isSave01 = true;}
//减法
void Widget::bnt_sub()
{double n1 = num1.toDouble();double n2 = num2.toDouble();double x = 0.0;if(symbol == "-"){//计算三位以上的式子x = n1 - n2;num1 = QString::number(x);qDebug()<<"x="<<x;}else if (symbol =="+"){x = n1 + n2;num1 = QString::number(x);}else if (symbol =="×"){x = n1 * n2;num1 = QString::number(x);}else if (symbol =="÷"){x = n1 / n2;num1 = QString::number(x);}else if(symbol == "%"){if(num1 == ""){ui->label_msg->setText("0");}else if(num2 != ""){num1 = QString::number(x);}}num2 = "";msg = "";//将式子放入信息栏中if(isSave01){msg.append(num1);}symbol = "-";msg.append(symbol);ui->label_msg->setText(msg);isSave01 = true;
}
//乘法
void Widget::bnt_mul()
{double n1 = num1.toDouble();double n2 = num2.toDouble();double x = 0.0;if(symbol == "×"){//计算三位以上的式子x = n1 * n2;num1 = QString::number(x);qDebug()<<"x="<<x;}else if (symbol =="-"){x = n1 - n2;num1 = QString::number(x);}else if (symbol =="+"){x = n1 + n2;num1 = QString::number(x);}else if (symbol =="÷"){x = n1 / n2;num1 = QString::number(x);}else if(symbol == "%"){if(num1 == ""){ui->label_msg->setText("0");}else if(num2 != ""){num1 = QString::number(x);}}num2 = "";msg = "";//将式子放入信息栏中if(isSave01){msg.append(num1);}symbol = "×";msg.append(symbol);ui->label_msg->setText(msg);isSave01 = true;}
//除法
void Widget::bnt_div()
{double n1 = num1.toDouble();double n2 = num2.toDouble();double x = 0.0;if(symbol == "÷"){//计算三位以上的式子x = n1 / n2;num1 = QString::number(x);qDebug()<<"x="<<x;}else if (symbol =="-"){x = n1 - n2;num1 = QString::number(x);}else if (symbol =="×"){x = n1 * n2;num1 = QString::number(x);}else if (symbol =="+"){x = n1 + n2;num1 = QString::number(x);}else if(symbol == "%"){if(num1 == ""){ui->label_msg->setText("0");}else if(num2 != ""){x = n1 / n2;num1 = QString::number(x);}}num2 = "";msg = "";//将式子放入信息栏中if(isSave01){msg.append(num1);}symbol = "÷";msg.append(symbol);ui->label_msg->setText(msg);isSave01 = true;
}
//等于
void Widget::bnt_over()
{if(isSave02){msg.append(num2);}double n1 = num1.toDouble();double n2 = num2.toDouble();double x = 0;if(symbol == "+"){//计算按下等于之后的结果x = n1 + n2;}else if(symbol == "-"){x = n1 - n2;}else if(symbol == "×"){x = n1 * n2;}else if(symbol == "÷"){if (n2 != 0){x = n1 / n2;}else{ui->label_idet->setText("除数不能为0");return;}}else if(symbol == "%"){//判断num1存在的同时num2也存在if(num1 == ""){ui->label_msg->setText("0");}else if(num2 != ""){}}else if(symbol == ""){x = n1;}msg.append("=");ui->label_msg->setText(msg);QString str = QString::number(x);ui->label_idet->setText(str);num1 = str;num2 = "";symbol = "";msg = "";isSave02 = true;}void Widget::on_clear_clicked(bool checked)
{//删除最近一项if(symbol == ""){num1 = "";ui->label_idet->setText("0");}else{num2 = "";ui->label_idet->setText("0");}}void Widget::on_clearall_clicked(bool checked)
{//删除所有项num1 = "";num2 = "";symbol = "";ui->label_idet->setText("0");msg = "";ui->label_msg->clear();
}void Widget::on_delete_2_clicked(bool checked)
{//删除一个数字if(symbol == ""){num1.chop(1);ui->label_idet->setText(num1);}else{num2.chop(1);ui->label_idet->setText(num2);}
}void Widget::on_fenshu_clicked(bool checked)
{//化为分数if(num1 == 0){ui->label_idet->setText("分母不能为0");}else{if(symbol == ""){double n1 = num1.toDouble();msg.append("1/(");msg.append(QString::number(n1));msg.append(")");ui->label_msg->setText(msg);n1 = 1 / num1.toDouble();QString str = QString::number(n1);num1 = str;ui->label_idet->setText(str);}else{double n2 = num2.toDouble();isSave02=false;msg.append("1/(");msg.append(QString::number(n2));msg.append(")");ui->label_msg->setText(msg);n2 = sqrt(num2.toDouble());qDebug() << "n2:" << n2 << endl;QString str = QString::number(n2);num2 = str;ui->label_idet->setText(str);}}
}void Widget::on_pow_clicked(bool checked)
{//平方if(symbol == ""){double n1 = num1.toDouble();msg.append("sqr(");msg.append(QString::number(n1));msg.append(")");ui->label_msg->setText(msg);n1 = num1.toDouble() * num1.toDouble();QString str = QString::number(n1);num1 = str;ui->label_idet->setText(str);}else{double n2 = num2.toDouble();isSave02=false;msg.append("sqr(");msg.append(QString::number(n2));msg.append(")");ui->label_msg->setText(msg);n2 = num2.toDouble() * num2.toDouble();qDebug() << "n2:" << n2 << endl;QString str = QString::number(n2);num2 = str;ui->label_idet->setText(str);}
}void Widget::on_genhao_clicked(bool checked)
{//开根号if(symbol == ""){double n1 = num1.toDouble();msg.append("根号(");msg.append(QString::number(n1));msg.append(")");ui->label_msg->setText(msg);n1 = sqrt(num1.toDouble());QString str = QString::number(n1);num1 = str;ui->label_idet->setText(str);}else{double n2 = num2.toDouble();isSave02=false;msg.append("根号(");msg.append(QString::number(n2));msg.append(")");ui->label_msg->setText(msg);n2 = sqrt(num2.toDouble());qDebug() << "n2:" << n2 << endl;QString str = QString::number(n2);num2 = str;ui->label_idet->setText(str);}}void Widget::on_aors_clicked(bool checked)
{//转换正负数if(symbol == ""){double n1 = num1.toDouble();n1 = -n1;num1 = QString::number(n1);ui->label_idet->setText(num1);qDebug() << "符号1：" << num1;}else{double n2 = num2.toDouble();n2 = -n2;num2 = QString::number(n2);ui->label_idet->setText(num2);qDebug() << "符号2：" << num2;}
}void Widget::on_yu_clicked(bool checked)//有问题
{//72 + 5% =3.6//72的5%是3.6，所以72+3.6就是75.6//将式子放入信息栏中double n1 = num1.toDouble();double n2 = num2.toDouble();double x;if(num1 != "" && num2 != ""){n2 = (n2 / 100) * n1 ;num2 = QString::number(n2);qDebug() << "n2 = "<<n2;}else if(num2 != ""){ui->label_msg->setText("0");}if(symbol == "÷"){//计算三位以上的式子x = n1 / n2;num1 = QString::number(x);qDebug()<<"x="<<x;}else if (symbol =="-"){x = n1 - n2;num1 = QString::number(x);}else if (symbol =="×"){x = n1 * n2;num1 = QString::number(x);}else if (symbol =="+"){x = n1 + n2;num1 = QString::number(x);}msg.append(num2);num2 = "";}