用QT实现的简单文本编辑器

头文件widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QPushButton>
#include <QTextEdit>
#include <QFont>
#include <QFontDialog>
#include <QColor>
#include <QColorDialog>
#include <QFile>
#include <QFileDialog>

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = nullptr);
    ~Widget();

private:
    Ui::Widget *ui;
    QPushButton *font_btn;   //字体按钮
    QPushButton *color_btn;  //颜色按钮
    QPushButton *open_btn;   //打开文件
    QPushButton *save_btn;   //保存文件
    QPushButton *clear_btn;  //清空按钮
    QTextEdit *textedit;     //文本编辑器

private slots:
    void font_btn_slot();
    void color_btn_slot();
    void open_btn_slot();
    void save_btn_slot();
    void clear_btn_slot();
};

#endif // WIDGET_H

功能函数widget.cpp

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

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

    this->setMinimumSize(640, 480);
    this->setWindowTitle("记事本-zzy");

    //文本编辑器
    textedit = new QTextEdit(this);
    textedit->resize(636, 400);
    textedit->move(2,0);


    //设置字体
    font_btn = new QPushButton("字体", this);
    font_btn->resize(90,40);
    font_btn->move(30, 420);
    connect(font_btn, &QPushButton::clicked, this, &Widget::font_btn_slot);

    //设置颜色
    color_btn = new QPushButton("颜色", this);
    color_btn->resize(90,40);
    color_btn->move(font_btn->x()+120, font_btn->y());
    connect(color_btn, &QPushButton::clicked, this, &Widget::color_btn_slot);

    //打开文件
    open_btn = new QPushButton("打开文件", this);
    open_btn->resize(90,40);
    open_btn->move(color_btn->x()+120, font_btn->y());
    connect(open_btn, &QPushButton::clicked, this, &Widget::open_btn_slot);

    //保存文件
    save_btn = new QPushButton("保存文件", this);
    save_btn->resize(90,40);
    save_btn->move(open_btn->x()+120, font_btn->y());
    connect(save_btn, &QPushButton::clicked, this, &Widget::save_btn_slot);

    //清空文本框
    clear_btn = new QPushButton("清空", this);
    clear_btn->resize(90,40);
    clear_btn->move(save_btn->x()+120, font_btn->y());
    connect(clear_btn, &QPushButton::clicked, this, &Widget::clear_btn_slot);
}

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

//设置字体
void Widget::font_btn_slot()
{
    bool ok;    //判断用户是否选择字体
    QFont font = QFontDialog::getFont(&ok, QFont("宋体", 12), this, "选择字体");
    if(ok)
    {
        textedit->setFont(font);
    }
}

//设置颜色
void Widget::color_btn_slot()
{
    QColor color = QColorDialog::getColor(QColor(255,0,0), this, "选择颜色");
    if(color.isValid())
    {
        //设置选中文本颜色
        textedit->setTextColor(color);
    }
}

//打开文件
void Widget::open_btn_slot()
{
    QString pathName = QFileDialog::getOpenFileName(this, "打开文件", "./", "All(*.*);; Text(*.txt);; C/C++(*.c *.cpp)");

    //判断用户是否选择文件
    if(!pathName.isEmpty())
    {
        //实例化文件对象
        QFile file(pathName);

        //判断文件是否存在
        if(file.exists())
        {
            //打开文件
            file.open(QIODevice::ReadOnly);

            //读取内容
            QByteArray text = file.readAll();
            textedit->setText(QString::fromLocal8Bit(text));

            //关闭文件
            file.close();
        }
    }
}

//保存文件
void Widget::save_btn_slot()
{
    QString pathName = QFileDialog::getSaveFileName(this, "保存文件", "./", "TEXT(*.txt)");

    //实例化文件对象
    QFile file(pathName);

    //打开文件
    file.open(QIODevice::WriteOnly | QIODevice::Truncate);

    //写入数据
    QString text = textedit->toPlainText();
    file.write(text.toLocal8Bit());

    //关闭文件
    file.close();
}

//清空文本框
void Widget::clear_btn_slot()
{
    textedit->clear();
}

运行结果