效果图：

TCP/UDP调试助手之TCP客户端，支持错误信息显示，断开连接后及时释放资源。

一、关键代码

1.在.pro文件中添加QT += network，包含头文件#include <QTcpSocket>

在类里定义一个QTcpSocket*成员m_tcpSocket

QTcpSocket* m_tcpSocket;

2.界面校验设置。界面上有两个lineEdit用来填写服务器的IP和端口，通过setValidator可以限制lineEdit输入的范围，端口号范围0-65535，IP地址用正则表达式校验，防止输入错误。

//设置端口输入校验ui->lineEdit_clientRemotePort->setValidator(new QIntValidator(0,65535));//ip校验正则QRegExp regExpIP("((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])[\\.]){3}(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])");//设置IP输入校验ui->lineEdit_clientRemoteIP->setValidator(new QRegExpValidator(regExpIP ,ui->lineEdit_serverLocalIp));

3.连接断开主要用到三个函数和两个信号。

3.1通过调用m_tcpSocket->connectToHost(ip,port);开始尝试连接服务器；

3.2m_tcpSocket->waitForConnected(1000)设置等待的时间，等待连接。在这里设置1000ms，1000ms内连上服务器，返回true ，没连上返回false；

3.3m_tcpSocket->abort();//终止连接，并且是立即关闭；

3.4信号error(QAbstractSocket::SocketError)，发生错误时发送信号，并传递错误信息；

3.5信号readyRead()，接收到数据时发送的信号。

//tcp客户端连接/断开void MainWindow::on_btn_clientConnect_clicked(){if(m_tcpSocket == nullptr){//获取本地端口bool ok;quint16 port=ui->lineEdit_clientRemotePort->text().toUShort(&ok);if(!ok){QMessageBox::warning(this,"错误","远程端口设置有误，请重新输入");return;}//获取本地IpQHostAddress ip(ui->lineEdit_clientRemoteIP->text());ip.toIPv4Address(&ok);if(!ok){QMessageBox::warning(this,"错误","远程ip设置有误，请重新输入");return;}this->m_tcpSocket=new QTcpSocket(this);m_tcpSocket->connectToHost(ip,port);connect(m_tcpSocket,SIGNAL(error(QAbstractSocket::SocketError)),this,SLOT(ClientReadError(QAbstractSocket::SocketError)));//等待连接if (m_tcpSocket->waitForConnected(1000)){connect(m_tcpSocket,SIGNAL(readyRead()),this,SLOT(ClinetReadData()));//更新UIui->text_clientRec->appendPlainText("已连接服务器"+QString("[%1：%2]\r\n").arg(ui->lineEdit_clientRemoteIP->text()).arg(ui->lineEdit_clientRemotePort->text()));ui->btn_clientConnect->setText("断开");ui->btn_clientConnect->setIcon(QIcon(":/Resource/Img/stop36x36.png"));ui->lineEdit_clientRemoteIP->setEnabled(false);ui->lineEdit_clientRemotePort->setEnabled(false);}else//连接失败{m_tcpSocket->disconnect();m_tcpSocket->deleteLater();m_tcpSocket=nullptr;ui->text_clientRec->appendPlainText("连接失败"+QString("[%1：%2]\r\n").arg(ui->lineEdit_clientRemoteIP->text()).arg(ui->lineEdit_clientRemotePort->text()));}}else{m_tcpSocket->disconnect();//断开信号槽m_tcpSocket->abort();//终止m_tcpSocket->deleteLater();//释放m_tcpSocket=nullptr;//更新UIui->text_clientRec->appendPlainText("已断开服务器"+QString("[%1：%2]\r\n").arg(ui->lineEdit_clientRemoteIP->text()).arg(ui->lineEdit_clientRemotePort->text()));ui->btn_clientConnect->setText("连接");ui->btn_clientConnect->setIcon(QIcon(":/Resource/Img/start36x36.png"));ui->lineEdit_clientRemoteIP->setEnabled(true);ui->lineEdit_clientRemotePort->setEnabled(true);}}

4.readyRead()信号触发的读取数据槽函数，调用m_tcpSocket->readAll();读取所有接收到的数据

//tcp客户端读取数据void MainWindow::ClinetReadData(){QByteArray ba = m_tcpSocket->readAll();QString data;//hexif(ui->chk_udpRecHex->isChecked()){this->ByteToHexString(data,ba);}else//普通字符串{data=QString::fromLocal8Bit(ba);}//显示ui->text_clientRec->insertPlainText(data);ui->text_clientRec->moveCursor(QTextCursor::End);}

5.发送数据，通过调用m_tcpSocket->write(byteArray);写入数据

//点击tcp客户端发送void MainWindow::on_btn_clientSend_clicked(){QByteArray byteArray;QString data=ui->text_clientSend->toPlainText();//Hex发送if(ui->chk_clientSendHex->isChecked()){//hex字符串转字节if(!HexStringToByte(data,byteArray)){QMessageBox::information(this,"提示","输入的十六进制字符串有误，请重新输入");return;}}//普通字符串发送else{byteArray= data.toLocal8Bit();}m_tcpSocket->write(byteArray);}

6.error(QAbstractSocket::SocketError)信号槽函数，显示错误信息并直接断开连接

//tcp客户端发生错误void MainWindow::ClientReadError(QAbstractSocket::SocketError){QString err=QString("发生错误:%1").arg(m_tcpSocket->errorString());ui->text_clientRec->appendPlainText(err);m_tcpSocket->disconnect();//断开所有信号m_tcpSocket->abort();//终止socket连接m_tcpSocket->deleteLater();//释放m_tcpSocket=nullptr;//更新UIui->text_clientRec->appendPlainText("已断开服务器"+QString("[%1：%2]\r\n").arg(ui->lineEdit_clientRemoteIP->text()).arg(ui->lineEdit_clientRemotePort->text()));ui->btn_clientConnect->setText("连接");ui->btn_clientConnect->setIcon(QIcon(":/Resource/Img/stop36x36.png"));ui->lineEdit_clientRemoteIP->setEnabled(true);ui->lineEdit_clientRemotePort->setEnabled(true);}

二、下载

tcp/udp调试助手