(1)客户端每隔10ms向服务器发送一次数字字符串,从0开始。
cpp
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QTcpSocket>
#include <QLabel>
#include <QTimer>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
private:
QTcpSocket *tcpClient; //socket
QLabel *LabSocketState; //状态栏显示标签
QString getLocalIP();//获取本机IP地址
protected:
void closeEvent(QCloseEvent *event);
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private slots:
//自定义槽函数
void onConnected();
void onDisconnected();
void onSocketStateChange(QAbstractSocket::SocketState socketState);
void onSocketReadyRead();//读取socket传入的数据
//
void on_actConnect_triggered();
void on_actDisconnect_triggered();
void on_actClear_triggered();
void on_pushButton_clicked();
void send_msg();
private:
Ui::MainWindow *ui;
QTimer* timer;
};
#endif // MAINWINDOW_H
关键:
QTimer* timer;
cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QHostAddress>
#include <QHostInfo>
#include <QThread>
QString MainWindow::getLocalIP()
{
QString hostName=QHostInfo::localHostName();//本地主机名
QHostInfo hostInfo=QHostInfo::fromName(hostName);
QString localIP="";
QList<QHostAddress> addList=hostInfo.addresses();//
if (!addList.isEmpty())
for (int i=0;i<addList.count();i++)
{
QHostAddress aHost=addList.at(i);
if (QAbstractSocket::IPv4Protocol==aHost.protocol())
{
localIP=aHost.toString();
break;
}
}
return localIP;
}
void MainWindow::closeEvent(QCloseEvent *event)
{
if (tcpClient->state()==QAbstractSocket::ConnectedState)
tcpClient->disconnectFromHost();
event->accept();
}
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
tcpClient=new QTcpSocket(this); //创建socket变量
timer = new QTimer(this);
connect(timer, SIGNAL(timeout()), this, SLOT(send_msg()));
LabSocketState=new QLabel("Socket状态:");//状态栏标签
LabSocketState->setMinimumWidth(250);
ui->statusBar->addWidget(LabSocketState);
QString localIP=getLocalIP();//本机IP
this->setWindowTitle(this->windowTitle()+"----本机IP:"+localIP);
ui->comboServer->addItem(localIP);
connect(tcpClient,SIGNAL(connected()),this,SLOT(onConnected()));
connect(tcpClient,SIGNAL(disconnected()),this,SLOT(onDisconnected()));
connect(tcpClient,SIGNAL(stateChanged(QAbstractSocket::SocketState)),
this,SLOT(onSocketStateChange(QAbstractSocket::SocketState)));
connect(tcpClient,SIGNAL(readyRead()),
this,SLOT(onSocketReadyRead()));
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::onConnected()
{ //connected()信号槽函数
ui->plainTextEdit->appendPlainText("**已连接到服务器");
ui->plainTextEdit->appendPlainText("**peer address:"+
tcpClient->peerAddress().toString());
ui->plainTextEdit->appendPlainText("**peer port:"+
QString::number(tcpClient->peerPort()));
ui->actConnect->setEnabled(false);
ui->actDisconnect->setEnabled(true);
}
void MainWindow::onDisconnected()
{//disConnected()信号槽函数
ui->plainTextEdit->appendPlainText("**已断开与服务器的连接");
ui->actConnect->setEnabled(true);
ui->actDisconnect->setEnabled(false);
}
void MainWindow::onSocketReadyRead()
{//readyRead()信号槽函数
while(tcpClient->canReadLine())
ui->plainTextEdit->appendPlainText("[in] "+tcpClient->readLine());
}
void MainWindow::onSocketStateChange(QAbstractSocket::SocketState socketState)
{//stateChange()信号槽函数
switch(socketState)
{
case QAbstractSocket::UnconnectedState:
LabSocketState->setText("scoket状态:UnconnectedState");
break;
case QAbstractSocket::HostLookupState:
LabSocketState->setText("scoket状态:HostLookupState");
break;
case QAbstractSocket::ConnectingState:
LabSocketState->setText("scoket状态:ConnectingState");
break;
case QAbstractSocket::ConnectedState:
LabSocketState->setText("scoket状态:ConnectedState");
break;
case QAbstractSocket::BoundState:
LabSocketState->setText("scoket状态:BoundState");
break;
case QAbstractSocket::ClosingState:
LabSocketState->setText("scoket状态:ClosingState");
break;
case QAbstractSocket::ListeningState:
LabSocketState->setText("scoket状态:ListeningState");
}
}
void MainWindow::on_actConnect_triggered()
{//连接到服务器
QString addr=ui->comboServer->currentText();
quint16 port=ui->spinPort->value();
tcpClient->connectToHost(addr,port);
// tcpClient->connectToHost(QHostAddress::LocalHost,port);
}
void MainWindow::on_actDisconnect_triggered()
{//断开与服务器的连接
if (tcpClient->state()==QAbstractSocket::ConnectedState)
tcpClient->disconnectFromHost();
}
void MainWindow::on_actClear_triggered()
{
ui->plainTextEdit->clear();
}
void MainWindow::on_pushButton_clicked()
{
timer->start(10);
}
void MainWindow::send_msg()
{
static int m = 0;
QString msg = QString::number(m);
ui->plainTextEdit->appendPlainText("[out] " + msg);
QByteArray str = msg.toUtf8();
str.append('\n');
tcpClient->write(str);
m++;
}
关键:
cpp
timer = new QTimer(this);
connect(timer, SIGNAL(timeout()), this, SLOT(send_msg()));
cpp
void MainWindow::on_pushButton_clicked()
{
timer->start(10);
}
void MainWindow::send_msg()
{
static int m = 0;
QString msg = QString::number(m);
ui->plainTextEdit->appendPlainText("[out] " + msg);
QByteArray str = msg.toUtf8();
str.append('\n');
tcpClient->write(str);
m++;
}
修改:
cpp
void MainWindow::on_pushButton_clicked()
{
timer->start(1);
}
客户端每1ms向服务器发送一个数字,此时也可以。
如果客户端中:
cpp
while (1)
{
QString msg = QString::number(1);
//ui->plainTextEdit->appendPlainText("[out] " + msg);
qDebug() << "[out] " + msg;
QByteArray str = msg.toUtf8();
str.append('\n');
tcpClient->write(str);
}
不断向服务器发送信息,此时页面是卡到一点都动不了,所以需要使用多线程来处理。
一种错误的写法:
cpp
#include "workThread.h"
#include <qapplication.h>
#include <qfiledialog.h>
#include <qdebug.h>
workThread::workThread(QTcpSocket* tcpClient,QObject *parent)
: QThread(parent)
{
qDebug()<<"workThread::workThread" << QThread::currentThread();
this->tcpClient = tcpClient;
timer = new QTimer(this);
connect(timer, &QTimer::timeout, this, [=]() {
ok = false;
});
timer->start(1000);
}
workThread::~workThread()
{
}
void workThread::run()
{
qDebug() <<"run():" << QThread::currentThread();
send_msg();
}
void workThread::send_msg()
{
qDebug() <<"send_msg():" << QThread::currentThread();
while (1)
{
QString msg = QString::number(1);
if (ok == false) {
qDebug() << "[out] " + msg;
ok = true;
}
QByteArray str = msg.toUtf8();
str.append('\n');
tcpClient->write(str);
}
}
workThread::workThread QThread(0xbde160)
run(): workThread(0xc744b0)
send_msg(): workThread(0xc744b0)
QSocketNotifier: Socket notifiers cannot be enabled or disabled from another thread
QSocketNotifier: Socket notifiers cannot be enabled or disabled from another thread报错-CSDN博客
cpp
class workThread : public QThread
{
Q_OBJECT
signals:
public:
workThread(QObject *parent);
~workThread();
protected:
void run();
private:
QTcpSocket* tcpClient; //socket
};
cpp
void workThread::run()
{
qDebug() <<"run():" << QThread::currentThread();
tcpClient = new QTcpSocket(this); //创建socket变量
}
这样写会导致:
QObject: Cannot create children for a parent that is in a different thread.
(Parent is workThread(0xc194f0), parent's thread is QThread(0xb7f940), current thread is workThread(0xc194f0)
关键在这句:
tcpClient = new QTcpSocket(this); //创建socket变量
this是主线程(0xb7f940)的,而当前线程是子线程(0xc194f0)。
tcpClient是子线程的(0xc194f0)。
不允许出现,父亲(this)与孩子(tcpClient)是不同线程的对象,这样的情况。
可以这样写:
cpp
void workThread::run()
{
qDebug() <<"run():" << QThread::currentThread();
tcpClient = new QTcpSocket; //创建socket变量
}
另一种错误写法:
cpp
void workThread::run()
{
qDebug() <<"run():" << QThread::currentThread();
tcpClient = new QTcpSocket; //创建socket变量
MainWindow* window = (MainWindow*)(parent());
connect(window, &MainWindow::connectToHost, this, &workThread::connectToHost, Qt::QueuedConnection);
qDebug() << "......";
}
void workThread::connectToHost(QString addr, quint16 port)
{
qDebug() << "workThread::connectToHost:" << QThread::currentThread();
tcpClient->connectToHost(addr, port);
}
run(): workThread(0x108f510)
......
workThread::connectToHost: QThread(0x100fa30)
QObject: Cannot create children for a parent that is in a different thread.
(Parent is QTcpSocket(0x109c458), parent's thread is workThread(0x108f510), current thread is QThread(0x100fa30)
run()函数:工作线程(0x108f510)
connectToHost槽函数:主线程(0x100fa30)
有一个QObject子类对象:假设它的对象名为m。
它的parent()为QTcpSocket(0x109c458),QTcpSocket(0x109c458)所在的线程是工作线程(0x108f510),当前线程是主线程(0x100fa30)。
然后出现了这样的错误。
这种情况和上面的错误情况类似。
关键:
主线程中的对象m
子线程的对象n
m不可以是n的parent
n不可以是m的parent
另一种思路:
再封装一个QObject子类:
cpp
#pragma once
#include <QObject>
#include <QTcpSocket>
#include <qtimer.h>
class socket : public QObject
{
Q_OBJECT
public:
socket(QObject *parent=nullptr);
~socket();
public slots:
void connectToHost(QString hostName, quint16 port);
void send_msg();
private:
QTcpSocket* tcpClient; //socket
QTimer* timer;
bool ok;
};
cpp
#include "socket.h"
#include <qdebug.h>
#include <QThread>
socket::socket(QObject *parent)
: QObject(parent)
{
qDebug() << "socket::socket:" << QThread::currentThread();
timer = new QTimer(this);
tcpClient = new QTcpSocket(this); //创建socket变量
connect(timer, &QTimer::timeout, this, [=]() {
ok = false;
});
timer->start(10000);
}
socket::~socket()
{
}
void socket::connectToHost(QString addr, quint16 port)
{
qDebug() << "socket::connectToHost:" << QThread::currentThread();
tcpClient->connectToHost(addr, port);
}
void socket::send_msg()
{
qDebug() <<"socket::send_msg():" << QThread::currentThread();
while (1)
{
QString msg = QString::number(1);
if (ok == false) {
qDebug() << "[out] " + msg;
ok = true;
}
QByteArray str = msg.toUtf8();
str.append('\n');
tcpClient->write(str);
}
}
cpp
void workThread::run()
{
qDebug() <<"run():" << QThread::currentThread();
tcp_client = new socket;
MainWindow* window = (MainWindow*)(parent());
connect(window, &MainWindow::connectToHost, tcp_client, &socket::connectToHost);
qDebug() << "......";
}
这样写的话,不会出现前面的问题。
但出现了新问题,window发送了connectToHost,而tcp_client没有执行connectToHost。
因为子线程没有开启事件循环。
【QT】跨线程的信号槽(connect函数)_qt跨线程信号槽-CSDN博客
QThread::exec();
cpp
void workThread::run()
{
qDebug() <<"run():" << QThread::currentThread();
tcp_client = new socket;
MainWindow* window = (MainWindow*)(parent());
connect(window, &MainWindow::connectToHost, tcp_client, &socket::connectToHost);
qDebug() << "......";
QThread::exec();
}
此时主线程就可以跨线程向子线程通过信号槽发送信息啦。
思考:
connect(window, &MainWindow::connectToHost, tcp_client, &socket::connectToHost);
connectToHost槽函数在哪个线程执行,取决于tcp_client对象在哪个线程。
客户端:
多线程版本
在子线程中:每1ms向服务器发送一次数据。
(还有很多bug)
(绑定的资源文件对应这个版本)