QT6中读取文件的实现方法详解

#include <QFile>
#include <QTextStream>
#include <QDebug>

void readTextFile() {
    QString filePath = "example.txt"; // 可以是含中文的路径
    
    QFile file(filePath);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        qDebug() << "无法打开文件:" << file.errorString();
        return;
    }
    
    QTextStream in(&file);
    in.setEncoding(QStringConverter::Utf8); // 设置编码为UTF-8
    
    while (!in.atEnd()) {
        QString line = in.readLine();
        qDebug() << line;
    }
    
    file.close();
}

void readFileDirectly() {
    QFile file("data.bin");
    if (!file.open(QIODevice::ReadOnly)) {
        qDebug() << "打开文件失败:" << file.errorString();
        return;
    }
    
    QByteArray data = file.readAll();
    // 处理二进制数据...
    
    file.close();
}

void readLargeFile() {
    QFile file("largefile.txt");
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        qDebug() << "打开文件失败:" << file.errorString();
        return;
    }
    
    const qint64 bufferSize = 1024 * 1024; // 1MB缓冲区
    QByteArray buffer(bufferSize, '\0');
    
    while (!file.atEnd()) {
        qint64 bytesRead = file.read(buffer.data(), buffer.size());
        if (bytesRead == -1) {
            qDebug() << "读取错误:" << file.errorString();
            break;
        }
        
        // 处理读取的数据
        QString chunk = QString::fromUtf8(buffer.constData(), bytesRead);
        qDebug() << "读取了" << bytesRead << "字节数据";
    }
    
    file.close();
}

void readStructuredData() {
    QFile file("data.dat");
    if (!file.open(QIODevice::ReadOnly)) {
        qDebug() << "打开文件失败:" << file.errorString();
        return;
    }
    
    QDataStream in(&file);
    in.setVersion(QDataStream::Qt_6_0);
    
    QString name;
    qint32 age;
    double score;
    
    in >> name >> age >> score;
    
    qDebug() << "姓名:" << name;
    qDebug() << "年龄:" << age;
    qDebug() << "分数:" << score;
    
    file.close();
}

#include <QFileInfo>

void getFileInfo() {
    QFileInfo fileInfo("example.txt");
    
    qDebug() << "文件路径:" << fileInfo.filePath();
    qDebug() << "文件名:" << fileInfo.fileName();
    qDebug() << "大小:" << fileInfo.size() << "字节";
    qDebug() << "最后修改时间:" << fileInfo.lastModified().toString();
}