37.Qt網絡與通信

本文轉載自查看原文 2018-04-14 13:44 1383 QT

1　　獲取本機網絡與通信

　　在網絡應用中,經常需要獲得本機的主機名.IP地址和硬件地址等網絡信息.運用QHostInfo,QNetWorkInterface,QNetworkAddressEntry可獲得本機的網絡信息.

widget.h

 1 #ifndef WIDGET_H
 2 #define WIDGET_H
 3 
 4 #include <QWidget>
 5 #include <QLabel>
 6 #include <QPushButton>
 7 #include <QLineEdit>
 8 #include <QGridLayout>
 9 #include <QMessageBox>
10 
11 #include <QHostInfo>
12 #include <QNetworkInterface>
13 
14 
15 namespace Ui {
16 class Widget;
17 }
18 
19 class Widget : public QWidget
20 {
21     Q_OBJECT
22 
23 public:
24     explicit Widget(QWidget *parent = 0);
25     ~Widget();
26 
27  private:
28     QLabel *hostLabel;
29     QLineEdit *LineEditLocalHostName;
30     QLabel *ipLabel;
31     QLineEdit *LineEditAddress;
32 
33     QPushButton *detailBtn;
34 
35     QGridLayout *mainLayout;
36 
37 private:
38     Ui::Widget *ui;
39 
40 public:
41     void getHostInformation(); 42 
43 public slots:
44     void slotDetail();
45 };
46 
47 #endif // WIDGET_H

widget.cpp

 1 #include "widget.h"
 2 #include "ui_widget.h"
 3 
 4 Widget::Widget(QWidget *parent) :
 5     QWidget(parent),
 6     ui(new Ui::Widget)
 7 {
 8     ui->setupUi(this);
 9     hostLabel = new QLabel(tr("主機名: "));
10     LineEditLocalHostName = new QLineEdit;
11     ipLabel = new QLabel(tr("IP 地址:"));
12     LineEditAddress = new QLineEdit;
13 
14     detailBtn = new QPushButton(tr("詳細"));
15 
16     mainLayout = new QGridLayout(this);
17     mainLayout->addWidget(hostLabel,0,0);
18     mainLayout->addWidget(LineEditLocalHostName,0,1);
19     mainLayout->addWidget(ipLabel,1,0);
20     mainLayout->addWidget(LineEditAddress,1,1);
21     //第二行第0個,占兩列
22     mainLayout->addWidget(detailBtn,2,0,1,2);
23 
24     getHostInformation();
25     connect(detailBtn,SIGNAL(clicked(bool)),this,SLOT(slotDetail()));
26 }
27 
28 Widget::~Widget()
29 {
30     delete ui;
31 }
32 
33 void Widget::getHostInformation()
34 {
35     //獲得本機主機名.QHostInfo提供了一系列有關網絡信息的靜態函數,
36     //可以根據主機名獲得分配的IP地址,也可以根據IP地址獲得相應的主機名
37 QString localHostName = QHostInfo::localHostName(); 38     LineEditLocalHostName->setText(localHostName);
39 
40     //根據主機名獲得相關主機信息,包括IP地址等.
41     //QHostInfo::fromName()函數通過主機名查找IP地址信息
42 QHostInfo hostInfo = QHostInfo::fromName(localHostName); 43 
44     //獲得主機的IP地址列表
45     QList<QHostAddress> listAddress = hostInfo.addresses();
46 
47     //在不為空的情況下,使用第一個IP地址
48     if(!listAddress.isEmpty())
49     {
50         LineEditAddress->setText(listAddress.first().toString());
51     }
52 }
53 
54 void Widget::slotDetail()
55 {
56     QString detail="";
57     //QNetworkInterface類提供了一個IP地址和網絡接口的列表
58     QList<QNetworkInterface> list=QNetworkInterface::allInterfaces();
59 
60     for(int i=0;i<list.count();i++)
61     {
62         QNetworkInterface interface=list.at(i);
63 
64         //獲得網絡接口的名稱
65         detail=detail+tr("設備: ")+interface.name()+"\n"; 66         //獲得網絡接口的名稱
67         detail=detail+tr("硬件地址:")+interface.hardwareAddress()+"\n"; 68 
69         //每個網絡接口包括0個或多個IP地址,
70         //每個IP地址有選擇性地與一個子網掩碼和一個廣播地址相關聯
71         //QNetworkAddressEntry類存儲了被網絡接口支持的一個IP地址,
72         //同時還包括與之相關的子網掩碼和廣播地址
73 QList<QNetworkAddressEntry> entryList=interface.addressEntries(); 74 
75 
76         for(int j=0;j<entryList.count();j++)
77         {
78             QNetworkAddressEntry entry = entryList.at(j);
79             detail=detail+"\t"+tr("IP地址: ")+entry.ip().toString()+"\n";
80             detail=detail+"\t"+tr("子網掩碼: ")+entry.netmask().toString()+"\n";
81             detail=detail+"\t"+tr("廣播地址: ")+entry.broadcast().toString()+"\n";
82         }
83         QMessageBox::information(this,tr("Detail"),detail);
84     }
85 }

main.cpp

 1 #include "widget.h"
 2 #include <QApplication>
 3 
 4 int main(int argc, char *argv[])
 5 {
 6     QApplication a(argc, argv);
 7     Widget w;
 8     w.show();
 9 
10     return a.exec();
11 }

2　　基於UDP的網絡廣播程序

　　2.1　　UDP(user data protocol)是一種簡單輕量級,不可靠,面向數據報無連接的傳輸協議,可以用在不是十分重要的場合

　　2.2　　UDP編程模型

　　在UDP方式下客戶端並不與服務器建立連接,它只負責調用發送函數向服務器法術數據報.類似的服務器不從客戶端接收連接,只負責調用接收函數,等待來自某客戶端的數據到達.Qt中通過QUdpSocket類實現UDP協議的編程.

服務器端:

udpserver.h

 1 #ifndef UDPSERVER_H
 2 #define UDPSERVER_H
 3 
 4 #include <QDialog>
 5 #include <QLabel>
 6 #include <QPushButton>
 7 #include <QVBoxLayout>
 8 #include <QLineEdit>
 9 #include <QUdpSocket>
10 #include <QTimer>
11 
12 namespace Ui {
13 class UdpServer;
14 }
15 
16 class UdpServer : public QDialog
17 {
18     Q_OBJECT
19 
20 public:
21     explicit UdpServer(QWidget *parent = 0,Qt::WindowFlags f=0);
22     ~UdpServer();
23 
24 public slots:
25     void StartBtnClicked();
26     void timeout();
27 
28 private:
29     int port;
30     bool isStarted;
31     QUdpSocket *udpSocket;
32     QTimer *timer;
33 
34 private:
35     QLabel *TimerLabel;
36     QLineEdit *TextLineEdit;
37     QPushButton *StartBtn;
38     QVBoxLayout *mainLayout;
39 
40 private:
41     Ui::UdpServer *ui;
42 
43 
44 };
45 
46 #endif // UDPSERVER_H

udpserver.cpp

 1 #include "udpserver.h"
 2 #include "ui_udpserver.h"
 3 
 4 #include <QHostAddress>
 5 
 6 UdpServer::UdpServer(QWidget *parent,Qt::WindowFlags f) :
 7     QDialog(parent,f),
 8     ui(new Ui::UdpServer)
 9 {
10     ui->setupUi(this);
11 
12     setWindowTitle(tr("UDP 服務器"));
13 
14     TimerLabel = new QLabel(tr("計時器:"),this);
15     TextLineEdit = new QLineEdit(this);
16     StartBtn = new QPushButton(tr("開始"),this);
17 
18     //設置垂直布局
19     mainLayout = new QVBoxLayout(this);
20     mainLayout->addWidget(TimerLabel);
21     mainLayout->addWidget(TextLineEdit);
22     mainLayout->addWidget(StartBtn);
23 
24     connect(StartBtn,SIGNAL(clicked(bool)),this,SLOT(StartBtnClicked()));
25 
26     //設置UDP的端口號參數,服務器定時向此端口發送廣播消息
27     port = 5555;
28     isStarted = false;
29     udpSocket = new QUdpSocket(this);
30     //創建定時器
31     timer = new QTimer(this);
32     //定時發送廣播消息
33     connect(timer,SIGNAL(timeout()),this,SLOT(timeout()));
34 }
35 
36 UdpServer::~UdpServer()
37 {
38     delete ui;
39 }
40 
41 void UdpServer::StartBtnClicked()
42 {
43     //打開
44     if(!isStarted)
45     {
46         StartBtn->setText(tr("停止"));
47         //每隔1000秒發送一個消息
48         timer->start(1000);
49         isStarted=true;
50     }
51     else
52     {
53         StartBtn->setText(tr("開始"));
54         isStarted = false;
55         timer->stop();
56     }
57 }
58 
59 void UdpServer::timeout()
60 {
61     QString msg = TextLineEdit->text();
62     int length=0;
63     if(msg=="")
64     {
65         return;
66     }
67 
68     //QHostAddress::Broadcast 指定向廣播地址發送
69     if(length=udpSocket->writeDatagram(msg.toLatin1(),
70                msg.length(),QHostAddress::Broadcast,port)!=msg.length())
71     {
72         return;
73     }
74 }

udpclient.h

 1 #ifndef UDPCLIENT_H
 2 #define UDPCLIENT_H
 3 
 4 #include <QDialog>
 5 #include <QVBoxLayout>
 6 #include <QTextEdit>
 7 #include <QPushButton>
 8 #include <QUdpSocket>
 9 
10 namespace Ui {
11 class UdpClient;
12 }
13 
14 class UdpClient : public QDialog
15 {
16     Q_OBJECT
17 
18 public:
19     explicit UdpClient(QWidget *parent = 0);
20     ~UdpClient();
21 
22 public slots:
23     void CloseBtnClicked();
24     void dataReceived();
25 
26 private:
27     int port;
28     QUdpSocket *udpSocket;
29 
30 private:
31     Ui::UdpClient *ui;
32     QTextEdit *ReceiveTextEdit;
33     QPushButton *closeBtn;
34     QVBoxLayout *mainLayout;
35 };
36 
37 #endif // UDPCLIENT_H

udpclient.cpp

 1 #include "udpclient.h"
 2 #include "ui_udpclient.h"
 3 #include <QMessageBox>
 4 #include <QHostAddress>
 5 
 6 UdpClient::UdpClient(QWidget *parent) :
 7     QDialog(parent),
 8     ui(new Ui::UdpClient)
 9 {
10     ui->setupUi(this);
11 
12     setWindowTitle(tr("UDP 客戶端"));
13 
14     ReceiveTextEdit = new QTextEdit(this);
15 
16     closeBtn = new QPushButton(tr("關閉"),this);
17 
18     mainLayout = new QVBoxLayout(this);
19     mainLayout->addWidget(ReceiveTextEdit);
20     mainLayout->addWidget(closeBtn);
21 
22     connect(closeBtn,SIGNAL(clicked(bool)),this,SLOT(CloseBtnClicked()));
23 
24     //設置UDP的端口號參數,指定在此端口上監聽數據
25     port = 5555;
26 
27     //創建一個QUdpSocket
28     udpSocket = new QUdpSocket(this);
29     //連接QIODevice的readyRead()信號
30     //QUdpSocket也是一個I/O設備,從QIODevice繼承而來,當有數據到達I/O設備時,發出readyRead()信號
31     connect(udpSocket,SIGNAL(readyRead()),this,SLOT(dataReceived()));
32 
33     //綁定到指定的端口上
34     bool result=udpSocket->bind(port);
35 
36     if(!result)
37     {
38         QMessageBox::information(this,tr("error"),tr("udp socket create error!"));
39         return;
40     }
41 }
42 
43 UdpClient::~UdpClient()
44 {
45     delete ui;
46 }
47 
48 void UdpClient::CloseBtnClicked()
49 {
50     close();
51 }
52 
53 void UdpClient::dataReceived()
54 {
55     //判斷UdpSocket中是否有數據報可讀
56     //hasPendingDatagrams()方法在至少有一個數據報可讀時返回true
57     while(udpSocket->hasPendingDatagrams())
58     {
59         //實現讀取第一個數據報
60         //pendingDataSize()可以獲得第一個數據報的長度
61         QByteArray datagram;
62         datagram.resize(udpSocket->pendingDatagramSize());
63         udpSocket->readDatagram(datagram.data(),datagram.size());
64 
65         QString msg = datagram.data();
66         //顯示數據內容
67         ReceiveTextEdit->insertPlainText(msg);
68     }
69 }

3　　基於TCP的網絡聊天室程序

　　TCP協議能為應用程序提供可靠的通信連接,使一台計算機發出的字節流無差錯地送達網絡上的其他計算機.因此,對可靠性要求高的數據通信系統往往使用TCP協議傳輸數據,但在正則收發數據前通信雙方必須首先建立連接.

　　首先啟動服務器,一段時間后啟動客戶端,它與此服務器經過三次握手后建立連接.此后的一段時間內,客戶端向服務器發送一個請求,服務器處理這個請求,並為客戶端發回一個響應.這個過程一直持續下去,知道客戶端為服務器發一個文件結束符,並關閉客戶端連接,接着服務器也關閉服務器的連接,結束運行或等待一個新的客戶端連接.

　　Qt中通過QTcpSocket類實現TCP協議的編程.

代碼示例:

服務器端

tcpserver.h

 1 #ifndef TCPSERVER_H
 2 #define TCPSERVER_H
 3 
 4 #include <QDialog>
 5 #include <QListWidget>
 6 #include <QLabel>
 7 #include <QLineEdit>
 8 #include <QPushButton>
 9 #include <QGridLayout>
10 #include "serverh.h"
11 
12 namespace Ui {
13 class TcpServer;
14 }
15 
16 class TcpServer : public QDialog
17 {
18     Q_OBJECT
19 
20 public:
21     explicit TcpServer(QWidget *parent = 0);
22     ~TcpServer();
23 
24 private:
25     Ui::TcpServer *ui;
26     QListWidget *ContentListWidget;
27     QLabel *PortLabe;
28     QLineEdit *PortLineEdit;
29     QPushButton *CreateBtn;
30     QGridLayout *mainLayout;
31 
32 private:
33     int port;
34     serverh *server;
35 
36 public slots:
37     void slotCreateServer();
38     void updateServer(QString,int);
39 
40 };
41 
42 #endif // TCPSERVER_H

tcpserver.cpp

 1 #include "tcpserver.h"
 2 #include "ui_tcpserver.h"
 3 
 4 TcpServer::TcpServer(QWidget *parent) :
 5     QDialog(parent),
 6     ui(new Ui::TcpServer)
 7 {
 8     ui->setupUi(this);
 9 
10     setWindowTitle(tr("TCP Server"));
11 
12     ContentListWidget = new QListWidget;
13 
14     PortLabe = new QLabel(tr("端口: "));
15     PortLineEdit = new QLineEdit();
16 
17     CreateBtn = new QPushButton(tr("創建聊天室"));
18 
19     mainLayout=new QGridLayout(this);
20     mainLayout->addWidget(ContentListWidget,0,0,1,2);
21     mainLayout->addWidget(PortLabe,1,0);
22     mainLayout->addWidget(PortLineEdit,1,1);
23     mainLayout->addWidget(CreateBtn,2,0,1,2);
24 
25     port=8010;
26     PortLineEdit->setText(QString::number(port));
27 
28     connect(CreateBtn,SIGNAL(clicked(bool)),this,SLOT(slotCreateServer()));
29 }
30 
31 TcpServer::~TcpServer()
32 {
33     delete ui;
34 }
35 
36 void TcpServer::slotCreateServer()
37 {
38     //創建一個serverh對象
39     server = new serverh(this,port);
40     //將serverh對象的updateServer()信號與相應的槽函數進行連接
41     connect(server,SIGNAL(updateServer(QString,int)),this,SLOT(updateServer(QString,int)));
42 
43     CreateBtn->setEnabled(false);
44 }
45 
46 void TcpServer::updateServer(QString msg , int length)
47 {
48     ContentListWidget->addItem(msg.left(length));
49 }

server.h

 1 #ifndef SERVERH_H
 2 #define SERVERH_H
 3 
 4 #include <QTcpServer>
 5 #include <QObject>
 6 
 7 #include "tcpclientsocket.h"//包含TCP的套接字
 8 
 9 class serverh : public QTcpServer
10 {
11     Q_OBJECT
12 public:
13     serverh(QObject *parent=0,int port=0);
14     //用來保存與每一個客戶端連接的TcpClientSocket
15     QList<tcpclientsocket*> tcpClientSocketList;
16 
17 signals:
18     void updateServer(QString,int);
19 
20 public slots:
21     void updateClients(QString,int);
22     void slotDisconnected(int);
23 
24 protected:
25     void incomingConnection(int socketDescriptor);
26 };
27 
28 #endif // SERVERH_H

server.cpp

 1 #include "serverh.h"
 2 
 3 serverh::serverh(QObject *parent,int port):QTcpServer(parent)
 4 {
 5     //在指定的端口對任意地址進行監聽
 6     //QHostAddress定義了幾種特殊的IP地址
 7     //QHostAddress定義了幾種特殊的IP地址,QHostAddress::Null表示一個空的地址
 8     //QHostAddress::LocalHost表示IPV4的本機地址127.0.0.1
 9     //QHostAddress::LocalHostIPV6表示IPv6的本機地址
10     //QHostAddress::Broadcast表示廣播地址255.255.255.255
11     //QHostAddress::Any表示Ipv4的任意地址0.0.0.0
12     //QHostAddress::AnyIPv6表示IPv6的任意地址
13     listen(QHostAddress::Any,port);
14 }
15 
16 //當出現一個新的連接時,QTcpServer觸發incomingConnection()函數,參數
17 //socketDescriptor指定連接的Socket描述符
18 void serverh::incomingConnection(int socketDescriptor)
19 {
20     qDebug() << "receive connect" << endl;
21     //創建一個新的TcpClientSocket客戶端通信
22     tcpclientsocket  *tcpClientSocket = new tcpclientsocket(this);
23     //連接TcpClientSocket的updateClients信號
24     connect(tcpClientSocket,SIGNAL(updateClients(QString,int)),this,
25             SLOT(updateClients(QString,int)));
26     //連接TcpClientSocket的disconnect信號
27     connect(tcpClientSocket,SIGNAL(disconnected(int)),this,
28             SLOT(slotDisconnected(int)));
29 
30     //將tcpClient加入客戶端套接字列表以便管理
31     tcpClientSocket->setSocketDescriptor(socketDescriptor);
32 
33     tcpClientSocketList.append(tcpClientSocket);
34 }
35 
36 void serverh::updateClients(QString msg, int length)
37 {
38     //發出updateServer信號,來通知服務器對話框更新相應的顯示狀態
39     qDebug() << msg << endl;
40     emit updateServer(msg,length);
41     qDebug() << msg << endl;
42     for(int i=0;i<tcpClientSocketList.count();i++)
43     {
44         QTcpSocket *item = tcpClientSocketList.at(i);
45         if(item->write(msg.toLatin1(),length)!=length)
46         {
47             continue;
48         }
49     }
50 }
51 
52 void serverh::slotDisconnected(int descriptor)
53 {
54     for(int i=0;i<tcpClientSocketList.count();i++)
55     {
56         QTcpSocket *item = tcpClientSocketList.at(i);
57 
58         if(item->socketDescriptor()==descriptor)
59         {
60             tcpClientSocketList.removeAt(i);
61             return;
62         }
63     }
64     return;
65 }

tcpclientsocket.h

 1 #ifndef TCPCLIENTSOCKET_H
 2 #define TCPCLIENTSOCKET_H
 3 
 4 #include <QTcpSocket>
 5 #include <QObject>
 6 
 7 class tcpclientsocket : public QTcpSocket
 8 {
 9     Q_OBJECT        //添加宏是為了實現信號和槽的通信
10 public:
11     tcpclientsocket(QObject *parent=0);
12 
13 signals:
14     void updateClients(QString ,int);
15     void disconnected(int);
16 
17 protected slots:
18     void dataReceived();
19     void slotDisconnected();
20 };
21 
22 #endif // TCPCLIENTSOCKET_H

tcpclientsocket.cpp

 1 #include "tcpclientsocket.h"
 2 #include <QDebug>
 3 
 4 tcpclientsocket::tcpclientsocket(QObject *parent)
 5 {
 6     //指定信號與槽的連接關系
 7     //readyRead()是QIODevice的signal,由QTcpSocket繼承而來.QIODevice
 8     //是所有輸入/輸出設備的一個抽象類,其中定義了基本的接口,在Qt中,QTcpSocket也被
 9     //看做一個QIODevice,readyRead()信號在有數據到來時發出
10     connect(this,SIGNAL(readyRead()),this,SLOT(dataReceived()));
11     //信號在斷開連接時發出
12     connect(this,SIGNAL(disconnected()),this,SLOT(slotDisconnected()));
13 }
14 
15 //當有數據到來的時候觸發dataReceived()函數,從套接字中將有效數據取出,然后
16 //發出updateClients()信號.
17 //updateClients()信號是通知服務器向聊天室內的所有成員廣播信息
18 void tcpclientsocket::dataReceived()
19 {
20     qDebug() << "accept message" << endl;
21     while(bytesAvailable()>0)
22     {
23         int length = bytesAvailable();
24         char buf[1024];
25         read(buf,length);
26 
27         qDebug() << buf << endl;
28         QString msg=buf;
29         qDebug() << msg << endl;
30         emit updateClients(msg,length);
31     }
32 }
33 
34 //槽函數slotDisconnected
35 void tcpclientsocket::slotDisconnected()
36 {
37     emit disconnected(this->socketDescriptor());
38 }

客戶端

tcpclient.h

 1 #ifndef TCPCLIENT_H
 2 #define TCPCLIENT_H
 3 
 4 #include <QDialog>
 5 
 6 namespace Ui {
 7 class TcpClient;
 8 }
 9 
10 #include <QDialog>
11 #include <QListWidget>
12 #include <QLineEdit>
13 #include <QPushButton>
14 #include <QLabel>
15 #include <QGridLayout>
16 
17 #include <QHostAddress>
18 #include <QTcpSocket>
19 
20 class TcpClient : public QDialog
21 {
22     Q_OBJECT
23 
24 public:
25     explicit TcpClient(QWidget *parent = 0);
26     ~TcpClient();
27 
28 private:
29     Ui::TcpClient *ui;
30     QListWidget *contentListWidget;
31     QLineEdit *sendLineEdit;
32     QPushButton *sendBtn;
33     QLabel *userNameLabel;
34     QLineEdit *userNameLineEdit;
35     QLabel *serverIPLabel;
36     QLineEdit *serverIPLineEdit;
37     QLabel *portLabel;
38     QLineEdit *portLineEdit;
39     QPushButton *enterBtn;
40     QGridLayout *mainLayout;
41 
42 private:
43     bool status;
44     int port;
45     QHostAddress *serverIP;
46     QString userName;
47     QTcpSocket *tcpSocket;
48 
49 private slots:
50     void slotEnter();
51     void slotConnected();
52     void slotDisconnected();
53     void dataReceived();
54     void slotSend();
55 
56 
57 };
58 
59 #endif // TCPCLIENT_H

tcpclient.cpp

  1 #include "tcpclient.h"
  2 #include "ui_tcpclient.h"
  3 
  4 #include <QMessageBox>
  5 #include <QHostInfo>
  6 
  7 TcpClient::TcpClient(QWidget *parent) :
  8     QDialog(parent),
  9     ui(new Ui::TcpClient)
 10 {
 11     ui->setupUi(this);
 12     setWindowTitle(tr("TCP Client"));
 13 
 14     contentListWidget = new QListWidget;
 15 
 16     sendLineEdit = new QLineEdit;
 17     sendBtn = new QPushButton(tr("發送"));
 18 
 19     userNameLabel=new QLabel(tr("用戶名:"));
 20     userNameLineEdit = new QLineEdit;
 21 
 22     serverIPLabel = new QLabel(tr("服務器地址: "));
 23     serverIPLineEdit = new QLineEdit;
 24 
 25     portLabel = new QLabel(tr("端口: "));
 26     portLineEdit = new QLineEdit;
 27 
 28     enterBtn = new QPushButton(tr("進入聊天室"));
 29 
 30     mainLayout = new QGridLayout(this);
 31     mainLayout->addWidget(contentListWidget,0,0,1,2);
 32     mainLayout->addWidget(sendLineEdit,1,0);
 33     mainLayout->addWidget(sendBtn,1,1);
 34     mainLayout->addWidget(userNameLabel,2,0);
 35     mainLayout->addWidget(userNameLineEdit,2,1);
 36     mainLayout->addWidget(serverIPLabel,3,0);
 37     mainLayout->addWidget(serverIPLineEdit,3,1);
 38     mainLayout->addWidget(portLabel,4,0);
 39     mainLayout->addWidget(portLineEdit,4,1);
 40     mainLayout->addWidget(enterBtn,5,0,1,2);
 41 
 42     status = false;
 43 
 44     port = 8010;
 45 
 46     portLineEdit->setText(QString::number(port));
 47 
 48     serverIP=new QHostAddress();
 49 
 50     connect(enterBtn,SIGNAL(clicked(bool)),this,SLOT(slotEnter()));
 51     connect(sendBtn,SIGNAL(clicked(bool)),this,SLOT(slotSend()));
 52 
 53     sendBtn->setEnabled(false);
 54 }
 55 
 56 TcpClient::~TcpClient()
 57 {
 58     delete ui;
 59 }
 60 
 61 void TcpClient::slotEnter()
 62 {
 63     //status表示當前的狀態,true表示已經進入聊天室,false表示已經離開聊天室
 64     //這里根據status的狀態決定是進入還是離開操作
 65     if(!status)
 66     {
 67         //完成輸入合法性檢驗
 68         QString ip = serverIPLineEdit->text();
 69         //用來判斷給定的IP地址是否能夠被正確解析
 70         if(!serverIP->setAddress(ip))
 71         {
 72             QMessageBox::information(this,tr("error"),tr("server ip address error!"));
 73             return;
 74         }
 75 
 76         if(userNameLineEdit->text()=="")
 77         {
 78             QMessageBox::information(this,tr("error"),tr("User name error!"));
 79             return;
 80         }
 81 
 82         userName = userNameLineEdit->text();
 83 
 84         //創建QTcpSocket類對象,並將信號/槽連接起來
 85         tcpSocket = new QTcpSocket(this);
 86         connect(tcpSocket,SIGNAL(connected()),this,SLOT(slotConnected()));
 87         connect(tcpSocket,SIGNAL(disconnected()),this,SLOT(slotDisconnected()));
 88         connect(tcpSocket,SIGNAL(readyRead()),this,SLOT(dataReceived()));
 89 
 90         //與TCP服務器端連接,連接成功后發出connected
 91         tcpSocket->connectToHost(*serverIP,port);
 92 
 93         status = true;
 94     }
 95     else
 96     {
 97         int length = 0;
 98         //構建一條離開聊天室的消息
 99         QString msg = userName + tr(":Leave Chat Room");
100         //通知服務器端以上構造的消息
101         if( ( length=tcpSocket->write( msg.toLatin1(),msg.length() )  )!=msg.length())
102         {
103             return;
104         }
105 
106         //與服務器端口連接,斷開后發出disconnected()信號
107         tcpSocket->disconnectFromHost();
108 
109         //將status狀態復位
110         status = false;
111     }
112 }
113 
114 //當服務器連上成功后,客戶端構造一條進入聊天室的消息,並通知服務器
115 void TcpClient::slotConnected()
116 {
117     qDebug() << "進入服務器" << endl;
118     sendBtn->setEnabled(true);
119     enterBtn->setText(tr("離開"));
120 
121     int length=0;
122 
123     QString msg = userName+tr("Enter Chat Room");
124     if((length=tcpSocket->write(msg.toLatin1(),msg.length()))!=msg.length())
125     {
126         qDebug() << "發送失敗" << endl;
127         return;
128     }
129     else
130     {
131         qDebug() << "發送成功" << endl;
132     }
133 }
134 
135 void TcpClient::slotDisconnected()
136 {
137     sendBtn->setEnabled(false);
138     enterBtn->setText(tr("進入聊天室"));
139 }
140 
141 //當有數據到來時觸發此函數,從套接字中將有效數據提出並顯示
142 void TcpClient::dataReceived()
143 {
144     while(tcpSocket->bytesAvailable()>0)
145     {
146         QByteArray datagram;
147         datagram.resize(tcpSocket->bytesAvailable());
148 
149         tcpSocket->read(datagram.data(),datagram.size());
150 
151         QString msg = datagram.data();
152         contentListWidget->addItem(msg.left(datagram.size()));
153     }
154 }
155 
156 void TcpClient::slotSend()
157 {
158     if(sendLineEdit->text()=="")
159     {
160         return;
161     }
162 
163     QString msg=userName+":"+sendLineEdit->text();
164 
165     tcpSocket->write(msg.toLatin1(),msg.length());
166     sendLineEdit->clear();
167 }

main.cpp

 1 #include "tcpclient.h"
 2 #include <QApplication>
 3 
 4 int main(int argc, char *argv[])
 5 {
 6     QApplication a(argc, argv);
 7     TcpClient w;
 8     w.show();
 9 
10     return a.exec();
11 }

4　　網頁瀏覽實例

　　首先創建一個QNetworkAccessManager類的實例,它用來發送網絡請求和接收應答.然后關聯了管理器的finished信號和自定義的槽,每當網絡應答結束時都會發射這個信號.最后使用了get函數來發送一個網絡請求,網絡請求使用QNetwrokRequest類表示,get()函數返回一個QNetworkReply對象

mainwindow.h

 1 #ifndef MAINWINDOW_H
 2 #define MAINWINDOW_H
 3 
 4 #include <QMainWindow>
 5 
 6 #include <QNetworkReply>
 7 #include <QNetworkAccessManager>
 8 class QNetworkAccessManager;
 9 
10 namespace Ui {
11 class MainWindow;
12 }
13 
14 class MainWindow : public QMainWindow
15 {
16     Q_OBJECT
17 
18 public:
19     explicit MainWindow(QWidget *parent = 0);
20     ~MainWindow();
21 
22 private slots:
23     void replyFinished(QNetworkReply *);
24 
25 
26 private:
27     Ui::MainWindow *ui;
28 
29     QNetworkAccessManager *manager;
30 };
31 
32 #endif // MAINWINDOW_H

mainwindow.cpp

 1 #include "mainwindow.h"
 2 #include "ui_mainwindow.h"
 3 
 4 #include <QtNetwork>
 5 
 6 
 7 MainWindow::MainWindow(QWidget *parent) :
 8     QMainWindow(parent),
 9     ui(new Ui::MainWindow)
10 {
11     ui->setupUi(this);
12 
13     //創建QNetworkAccessManager類的實例,它用來發送網絡請求和接收應答.然后
14     //管理了管理器的finished()信號和自定義的槽,每當網絡應答結束時都會發射
15     //這個信號.最后使用了get()函數來發送一個網絡請求,網絡請求使用QNetworkRequest
16     //類表示,get()函數返回一個QNetworkReply對象
17     manager = new QNetworkAccessManager(this);
18     connect(manager,SIGNAL(finished(QNetworkReply*)),this,
19             SLOT(replyFinished(QNetworkReply*)));
20     manager->get(QNetworkRequest(QUrl("http://www.baidu.com")));
21 }
22 
23 MainWindow::~MainWindow()
24 {
25     delete ui;
26 }
27 
28 void MainWindow::replyFinished(QNetworkReply *reply)
29 {
30     QString all = reply->readAll();
31     ui->textBrowser->setText(all);
32     reply->deleteLater();
33 }

main.cpp

 1 #include "mainwindow.h"
 2 #include <QApplication>
 3 
 4 int main(int argc, char *argv[])
 5 {
 6     QApplication a(argc, argv);
 7     MainWindow w;
 8     w.show();
 9 
10     return a.exec();
11 }

文件下載示例

mianwindow.h

 1 #ifndef MAINWINDOW_H
 2 #define MAINWINDOW_H
 3 
 4 #include <QMainWindow>
 5 
 6 #include <QNetworkReply>
 7 #include <QNetworkAccessManager>
 8 class QNetworkAccessManager;
 9 
10 #include <QUrl>
11 class QFile;
12 
13 namespace Ui {
14 class MainWindow;
15 }
16 
17 class MainWindow : public QMainWindow
18 {
19     Q_OBJECT
20 
21 public:
22     explicit MainWindow(QWidget *parent = 0);
23     ~MainWindow();
24 
25     void startRequest(QUrl url);
26 
27 private slots:
28     void replyFinished(QNetworkReply *);
29     void httpFinished();
30     void httpReadyRead();
31     void updateDataReadProgress(qint64,qint64);
32 
33 
34     void on_pushButton_clicked();
35 
36 private:
37     Ui::MainWindow *ui;
38 
39     QNetworkAccessManager *manager;
40 
41     QNetworkReply *reply;
42     QUrl url;
43     QFile *file;
44 };
45 
46 #endif // MAINWINDOW_H

mainwindow.cpp

  1 #include "mainwindow.h"
  2 #include "ui_mainwindow.h"
  3 
  4 #include <QtNetwork>
  5 
  6 
  7 MainWindow::MainWindow(QWidget *parent) :
  8     QMainWindow(parent),
  9     ui(new Ui::MainWindow)
 10 {
 11     ui->setupUi(this);
 12 
 13     //創建QNetworkAccessManager類的實例,它用來發送網絡請求和接收應答.然后
 14     //管理了管理器的finished()信號和自定義的槽,每當網絡應答結束時都會發射
 15     //這個信號.最后使用了get()函數來發送一個網絡請求,網絡請求使用QNetworkRequest
 16     //類表示,get()函數返回一個QNetworkReply對象
 17     manager = new QNetworkAccessManager(this);
 18     connect(manager,SIGNAL(finished(QNetworkReply*)),this,
 19             SLOT(replyFinished(QNetworkReply*)));
 20 //    manager->get(QNetworkRequest(QUrl("http://www.baidu.com")));
 21 
 22     //ui->progressBar->hide();
 23 }
 24 
 25 MainWindow::~MainWindow()
 26 {
 27     delete ui;
 28 }
 29 
 30 void MainWindow::startRequest(QUrl url)
 31 {
 32     //使用get()函數發送網絡請求
 33     reply = manager->get(QNetworkRequest(url));
 34     //readyRead()信號繼承自QIODevice類,每當有新的數據可以讀取時,都會發射該信號
 35     connect(reply,SIGNAL(readyRead()),this,SLOT(httpReadyRead()));
 36 
 37     //每當網絡請求的下載進度更新時都會發射downloadProgress()信號,用於更新進度條;
 38     connect(reply,SIGNAL(downloadProgress(qint64,qint64)),this,
 39             SLOT(updateDataReadProgress(qint64,qint64)));
 40 
 41     //每當應答處理結束時,都會發射finished()信號
 42     connect(reply,SIGNAL(finished()),this,SLOT(httpFinished()));
 43 }
 44 
 45 void MainWindow::replyFinished(QNetworkReply *reply)
 46 {
 47     QString all = reply->readAll();
 48     ui->textBrowser->setText(all);
 49     reply->deleteLater();
 50 }
 51 
 52 //完成下載后,重新隱藏進度條,刪除reply和file對象
 53 void MainWindow::httpFinished()
 54 {
 55     ui->progressBar->hide();
 56     file->flush();
 57     file->close();
 58     reply->deleteLater();
 59     reply = 0;
 60     delete file;
 61     file = 0;
 62 }
 63 
 64 //首先判斷是否創建了文件,如果是,則讀取返回的所有數據,然后寫入文件中.
 65 //該文件示后面的下載按鈕單機信號槽中創建並打開的
 66 void MainWindow::httpReadyRead()
 67 {
 68     if(file)
 69     {
 70         file->write(reply->readAll());
 71     }
 72 }
 73 
 74 //設置進度條的最大值和當前值
 75 void MainWindow::updateDataReadProgress(qint64 bytesRead, qint64 totalBytes)
 76 {
 77     ui->progressBar->setMaximum(totalBytes);
 78     ui->progressBar->setValue(bytesRead);
 79 }
 80 
 81 //使用要下載的文件名創建了本地文件,使用輸入的url進行網絡請求,並顯示進度條
 82 void MainWindow::on_pushButton_clicked()
 83 {
 84     url = ui->lineEdit->text();
 85     QFileInfo info(url.path());
 86     QString fileName(info.fileName());
 87     qDebug() << fileName<<endl;
 88     file = new QFile(fileName);
 89 
 90     if(!file->open(QIODevice::WriteOnly))
 91     {
 92         qDebug()<<"file open error";
 93         delete file;
 94         file = 0;
 95         return;
 96     }
 97     startRequest(url);
 98     ui->progressBar->setValue(0);
 99     ui->progressBar->show();
100 }

免責聲明！

本站轉載的文章為個人學習借鑒使用，本站對版權不負任何法律責任。如果侵犯了您的隱私權益，請聯系本站郵箱yoyou2525@163.com刪除。

猜您在找 網絡與通信基礎 Android的網絡與通信 [轉]Android的網絡與通信計算機網絡與通信網絡 37.Qt Creator安裝及配置CMake編譯器的方法 2021粵港澳大灣區智能網絡與通信系統論壇-1026~1027-線上 QT socket網絡通信 37.qt quick- 高仿微信實現局域網聊天V3版本(添加登錄界面、UDP校驗登錄、皮膚更換、3D旋轉) 48.QT-網絡通信講解1 Qt開源作品37-網絡中轉服務器