迅為4412開(kāi)發(fā)板Qt網(wǎng)絡(luò)編程

1、迅為4412開(kāi)發(fā)板qt網(wǎng)絡(luò)編程步驟二：編寫(xiě)代碼1.創(chuàng)建 qudpsocket 對(duì)象，用法 bind 函數(shù)綁定端口號(hào)和套接字，數(shù)據(jù)報(bào)到來(lái)后會(huì)發(fā)出信 號(hào)()，在綁定的槽函數(shù)內(nèi)去讀取數(shù)據(jù)。2.讀取數(shù)據(jù)，數(shù)據(jù)到來(lái) haspendingdatagrams()返回 true，再用 pendingdatagramsize（）獵取數(shù)據(jù)報(bào)的長(zhǎng)度，假如數(shù)據(jù)沒(méi)有被讀取完，haspendingdatagrams()就會(huì)返回 true，直至數(shù)據(jù)都被讀取完。readdatagram(data，size）；參數(shù) data 為讀取的數(shù)據(jù)，size 為數(shù)據(jù)長(zhǎng)度。3.發(fā)送數(shù)據(jù)，用法 writedatagram 函數(shù)，writed

2、atagram(const char *data, qint64 len, const qhostaddress &host, quint16 port)；data:發(fā)送的數(shù)據(jù)。len：發(fā)送的數(shù)據(jù)長(zhǎng)度。host：目標(biāo) ip 地址。port：目標(biāo)端口號(hào)。4.關(guān)閉 socket 套接字。代碼如下：udp.hincludeincludenamespace ui class udp;class udp : public qmainwindowq_objectpublic:explicit udp(qwidget *parent = 0); udp();qudpsocket * udpsocke

3、t;private slots:void on_pushbutton_clicked();void readyread_slot(void);void on_pushbutton_3_clicked();void on_pushbutton_2_clicked();private:ui:udp *ui;udp.cpp:udp:udp(qwidget *parent) :qmainwindow(parent), ui(new ui:udp)ui->setupui(this);udpsocket = new qudpsocket(this);udp:udp()delete ui;/* 打開(kāi)按

4、鈕*/void udp:on_pushbutton_clicked()/綁定本端口的端口號(hào)if(udpsocket->bind(ui->cliedit->text().touint() = true)qmessagebox:information(this,"提醒","勝利");elseqmessagebox:information(this,"提醒","失敗");/綁定數(shù)據(jù)信號(hào)和槽函數(shù)connect(udpsocket,signal(readyread(),this,slot(readyread

5、_slot();/*讀取數(shù)據(jù)槽函數(shù)*/void udp:readyread_slot()qstring buf;qbytearray array;/haspendingdatagrams()返回 true 時(shí)表示起碼有一個(gè)數(shù)據(jù)報(bào)在等待被讀取while(udpsocket->haspendingdatagrams()/獵取數(shù)據(jù)array.resize(udpsocket->pendingdatagramsize();udpsocket->readdatagram(array.data(),array.size();buf = array.data();ui->recved

6、it->appendplaintext(buf);/* 發(fā)送數(shù)據(jù)*/void udp:on_pushbutton_3_clicked()quint16 port;qstring sendbuff;qhostaddress address;address.setaddress(ui->ipedit->text();/目標(biāo)機(jī)地址port = ui->portedit->text().toint();/目標(biāo)機(jī)端口號(hào)sendbuff = ui->sendedit->text();/發(fā)送的數(shù)據(jù)/發(fā)送udpsocket->writedatagram(sendbuff.tolocal8bit().data(),sendbuff.length(),address,p