目录

一、文件普通读写和流式读写

二、目录遍历和文件属性读写

三、进程

四、线程

五、线程同步

六、线程互斥

一、文件普通读写和流式读写

#ifndef WIDGET_H
#define WIDGET_H#include 
#include 
#include 
#include 
#include 
#include class Widget : public QWidget
{Q_OBJECTpublic:Widget(QWidget *parent = 0);~Widget();
public slots:void showfile(){QString filename = QFileDialog::getOpenFileName();le->setText(filename);
#if 0//普通写法QFile file(filename);if (!file.open(QIODevice::ReadOnly | QIODevice::Text))return;while (!file.atEnd()) {QByteArray line = file.readLine();// process_line(line);te->append(line);}
#endif//适配器写法用流来操作流支持输出运算符QFile file(filename);if (!file.open(QIODevice::ReadOnly | QIODevice::Text))return;QTextStream in(&file);while (!in.atEnd()) {QString line = in.readLine();//  process_line(line);te->append(line);}}private:QTextEdit *te;QLineEdit *le;QPushButton *pb;
};#endif // WIDGET_H

#include "widget.h"
#include Widget::Widget(QWidget *parent): QWidget(parent)
{te = new QTextEdit;te->setMinimumSize(640, 480);le = new QLineEdit;pb = new QPushButton("showtxt");QVBoxLayout *vbox = new QVBoxLayout;vbox->addWidget(te);vbox->addWidget(le);vbox->addWidget(pb);setLayout(vbox);connect(pb, SIGNAL(clicked(bool)), this, SLOT(showfile()));
}Widget::~Widget()
{}

 用两种方式来读文件，都在代码里。最好的学习方式就是根据代码学

之前教我进程线程的老师是这样说的，我也很赞同这个观点，所以自己看代码吧

二、目录遍历和文件属性读写

新建一个控制台程序

只有一个主函数，没有GUI

 运行起来也只是一个黑框框

 我们写个程序来试试

#include 
#include 
#include 
#include int main(int argc, char *argv[])
{QCoreApplication a(argc, argv);QDir dir;QFileInfoList list = dir.entryInfoList();std::cout << "Bytes     Filename" << std::endl;for (int i = 0; i < list.size(); ++i) {QFileInfo fileInfo = list.at(i);std::cout << fileInfo.size()<< "\t"<

#ifndef WIDGET_H
#define WIDGET_H#include 
#include 
#include 
#include 
#include 
#include class Widget : public QWidget
{Q_OBJECTpublic:Widget(QWidget *parent = 0);~Widget();
public slots:void showfile(){QString filename = QFileDialog::getOpenFileName();le->setText(filename);QStringList arg = {filename};QProcess ppp;ppp.execute("notepad", arg);}private:QLineEdit *le;QPushButton *pb;
};#endif // WIDGET_H

#include "widget.h"
#include Widget::Widget(QWidget *parent): QWidget(parent)
{le = new QLineEdit;pb = new QPushButton("showtxt");QVBoxLayout *vbox = new QVBoxLayout;vbox->addWidget(le);vbox->addWidget(pb);setLayout(vbox);connect(pb, SIGNAL(clicked(bool)), this, SLOT(showfile()));
}Widget::~Widget()
{}