能发送数据报，却接收不到（udp）

bzyzhang

使用writeDatagram()发送一个数据报给485模块，485模块收到后将对应传感器的信息（9字节的16进制）返回。现在的问题是，成功发送数据报，可是却接收不到。代码如下：

1. #include<QNetworkInterface>
   
2. #include<QMessageBox>
   
3. #include<QHostInfo>
   
4. #include"networkinformation.h"
   
5. 
   
6. 
   
7. NetworkInformation::NetworkInformation(QWidget *parent)
   
8.         :QWidget(parent)
   
9. {
   
10.         hostLabel=new QLabel(tr("tem:"));
    
11.         LineEditLocalHostName=new QLineEdit;
    
12.         ipLabel=new QLabel(tr("hum："));
    
13.         LineEditAddress=new QLineEdit;
    
14. 
    
15.         detailBtn=new QPushButton(tr("send"));
    
16. 
    
17.         mainLayout=new QGridLayout(this);
    
18.         mainLayout->addWidget(hostLabel,0,0);
    
19.         mainLayout->addWidget(LineEditLocalHostName,0,1);
    
20.         mainLayout->addWidget(ipLabel,1,0);
    
21.         mainLayout->addWidget(LineEditAddress,1,1);
    
22.         mainLayout->addWidget(detailBtn,2,0,1,2);
    
23. 
    
24.         setWindowTitle("Network");
    
25. 
    
26.         connect(detailBtn,SIGNAL(clicked()),this,SLOT(slotDetail()));
    
27.        
    
28.         //port=8000;
    
29.         udpsocket=new QUdpSocket(this);
    
30.         receiver=new QUdpSocket(this);
    
31.         //receiver->bind(8000,QUdpSocket::ShareAddress);
    
32.         connect(receiver,SIGNAL(readyRead()),this,SLOT(processPendingDatagram()));
    
33. 
    
34. }
    
35. 
    
36. 
    
37. 
    
38. void NetworkInformation::slotDetail()
    
39. {
    
40.         //char str[128]={0x01,0x04,0x00,0x00,0x00,0x02,0x71,0xcb};
    
41.         QByteArray ba;
    
42.         ba.resize(8);
    
43.         ba[0]=0x01;
    
44.         ba[1]=0x04;
    
45.         ba[2]=0x00;
    
46.         ba[3]=0x00;
    
47.         ba[4]=0x00;
    
48.         ba[5]=0x02;
    
49.         ba[6]=0x71;
    
50.         ba[7]=0xcb;
    
51.         qint64 len;
    
52.         QHostAddress adr=QHostAddress("192.168.1.33");
    
53. 
    
54.         //len=udpsocket->writeDatagram(str,32,adr,port);
    
55.         len=udpsocket->writeDatagram(ba,adr,8000);
    
56. 
    
57.         if(len==-1)
    
58.         {
    
59.                 QMessageBox::information(this,tr("error"),tr("writedatagram failed!"));
    
60.                 return;
    
61.         }
    
62.         qDebug()<<"yes"<<len;
    
63. }
    
64. 
    
65. void NetworkInformation::processPendingDatagram()
    
66. {
    
67.         while(receiver->hasPendingDatagrams())
    
68.         {
    
69.                 qDebug()<<"hasPendingDatagrams";
    
70.                 QByteArray datagram;
    
71.                 qint64 rlen;
    
72.                 datagram.resize(receiver->pendingDatagramSize());
    
73. 
    
74.                 rlen=receiver->readDatagram(datagram.data(),datagram.size());
    
75. 
    
76.                 if(rlen==-1)
    
77.                 {
    
78.                         QMessageBox::information(this,tr("error"),tr("readdatagram failed!"));
    
79.                         return;
    
80.                 }
    
81.         }
    
82. }

复制代码