英语注释都是从Qt助手那里抄来的，英语不好，不翻译。
启动程序时，必须先启动服务端，然后启动客户端才能连接。 如果在启动客户端后启动服务端，将无法连接。
我想在客户端建立一个死循环，一直检测连接是否成功，一直连接到连接为止，通过退出循环，即使先启动客户端也能连接。
客户端：
//构件. h # ifndef构件_ h # define构件_ h # includeqwidget # includeqhboxlayout # includeqvboxlayout # includeqpuput includeqbytearray # includeqstringclasswidget 3360 publicqwidget { q _ objectpublling } ~小部件()； void initUi (； //初始化接口void newTcpConnect (； //创建新的连接专用插槽3360语音发送消息； //发送消息的void receiveMessage ()； //接收消息private: QTextEdit *myEdit，*yourEdit； QPushButton *sendButton，*closeButton； QHBoxLayout *hlayout； QVBoxLayout *vlayout，*alllayout； qtcpsocket*TCP插座； (； # endif//构件_ h//构件. CPP # include '构件. h '构件33603360构件(q构件* parent ) pareet 连接(close button，signal ) clicked(bool )、this，slot (close ) ) tcpSocket=new QTcpSocket； newTcpConnect (； //thissignalisemittedonceeverytimenewdataisavailableforreadingfromthedevice.connect (TCP套接字，信号) (readyread ) ) }语音构件：3360 init ui ((this-resize ) 500，500 )； 设置窗口标题(客户端)； send button=newq push button (' send '，this )； close button=newq push button (' close '，this )； 我的编辑=newq textedit (this； YouRedit=newqtextedit(this； hlayout=new QHBoxLayout； hlayout-addstretch(6； h布局添加构件(关闭按钮； h布局添加构件(send button； vlayout=new QVBoxLayout； v layout-add构件(youredit，2 )； v layout-add构件(我的编辑，1 )； alllayout=new QVBoxLayout； alllayout-addlayout(vlayout； alllayout-addlayout(hlayout； 设置布局(al layout； } void构件：3360 newtcpconnect ()/abortsthecurrentconnectionandresetsthesocket.//unlikedisconnectfromhost ) ) ) thisfunctionimmediatelyclosesthesocket，discardinganypendingdatainthewritebuffer.TCP socket-abort； //attemptstomakeaconnectiontohostnameonthegive
n port. tcpSocket->connectToHost("127.0.0.1",9999);}void Widget::sendMessage(){ QString str = myEdit->toPlainText(); yourEdit->append(str); myEdit->clear(); QByteArray data = str.toUtf8(); tcpSocket->write(data);}void Widget::receiveMessage(){ //Reads all remaining data from the device, and returns it as a byte array. QByteArray data = tcpSocket->readAll(); QString str(data); yourEdit->append(str);}Server:
//widget.h#ifndef WIDGET_H#define WIDGET_H#include <QWidget>#include <QHBoxLayout>#include <QVBoxLayout>#include <QPushButton>#include <QTextEdit>#include <QTcpSocket>#include <QTcpServer>#include <QAbstractSocket>#include <QByteArray>#include <QString>class Widget : public QWidget{ Q_OBJECTpublic: Widget(QWidget *parent = 0); ~Widget(); void initUi(); //初始化界面 void newListen(); //建立tcp监听事件private slots: void acceptConnect(); //接受客户端连接 void sendMessage(); //发送消息 void receiveMessage(); //接收消息private: QTextEdit *myEdit,*yourEdit; QPushButton *sendButton,*closeButton; QHBoxLayout *hlayout; QVBoxLayout *vlayout,*alllayout; QTcpServer *tcpServer; QTcpSocket *tcpSocket;};#endif // WIDGET_H//widget.cpp#include "widget.h"Widget::Widget(QWidget *parent) : QWidget(parent){ initUi(); tcpSocket = new QTcpSocket; tcpServer = new QTcpServer; newListen(); //This signal is emitted every time a new connection is available. connect(tcpServer,SIGNAL(newConnection()),SLOT(acceptConnect())); //This signal is emitted after an error occurred. //The socketError parameter describes the type of error that occurred. connect(tcpSocket,SIGNAL(error(QAbstractSocket::SocketError)),this,SLOT(close()));}Widget::~Widget(){ delete tcpSocket; delete tcpServer;}void Widget::initUi(){ this->resize(500,500); this->setWindowTitle("Server"); sendButton = new QPushButton("send",this); closeButton = new QPushButton("close",this); myEdit = new QTextEdit(this); yourEdit = new QTextEdit(this); connect(sendButton,SIGNAL(clicked(bool)),this,SLOT(sendMessage())); connect(closeButton,SIGNAL(clicked(bool)),this,SLOT(close())); hlayout = new QHBoxLayout; hlayout->addStretch(6); hlayout->addWidget(closeButton); hlayout->addWidget(sendButton); vlayout = new QVBoxLayout; vlayout->addWidget(yourEdit,2); vlayout->addWidget(myEdit,1); alllayout = new QVBoxLayout; alllayout->addLayout(vlayout); alllayout->addLayout(hlayout); this->setLayout(alllayout);}void Widget::newListen(){ //Tells the server to listen for incoming connections on address address and port port. //If port is 0, a port is chosen automatically. If address is QHostAddress::Any, the server will listen on all network interfaces. if(!tcpServer->listen(QHostAddress::Any,9999)) { qDebug()<<tcpServer->errorString(); tcpServer->close(); }}void Widget::acceptConnect(){ //Returns the next pending connection as a connected QTcpSocket object. tcpSocket = tcpServer->nextPendingConnection(); connect(tcpSocket,SIGNAL(readyRead()),SLOT(receiveMessage()));}void Widget::sendMessage(){ QString str = myEdit->toPlainText(); yourEdit->append(str); myEdit->clear(); QByteArray data = str.toUtf8(); tcpSocket->write(data);}void Widget::receiveMessage(){ QByteArray data = tcpSocket->readAll(); QString str(data); yourEdit->append(str);}