C++ Qt开发之使用QUdpSocket实现UDP网络通信

　　函数描述QUdpSocket(QObject *parent = nullptr)构造函数，创建一个新的 QUdpSocket 对象。~QUdpSocket()析构函数，释放 QUdpSocket 对象及其资源。void bind(const QHostAddress &address, quint16 port, BindMode mode = DefaultForPlatform)将套接字绑定到指定的本地地址和端口。void close()关闭套接字。bool joinMulticastGroup(const QHostAddress &groupAddress, const QNetworkInterface &iface = QNetworkInterface())加入多播组。bool leaveMulticastGroup(const QHostAddress &groupAddress, const QNetworkInterface &iface = QNetworkInterface())离开多播组。qint64 pendingDatagramSize() const返回下一个待读取的数据报的大小。qint64 readDatagram(char *data, qint64 maxSize, QHostAddress *address = nullptr, quint16 *port = nullptr)读取数据报。QByteArray readDatagram(qint64 maxSize, QHostAddress *address = nullptr, quint16 *port = nullptr)读取数据报，返回 QByteArray 对象。qint64 writeDatagram(const char *data, qint64 size, const QHostAddress &address, quint16 port)发送数据报。qint64 writeDatagram(const QByteArray &datagram, const QHostAddress &address, quint16 port)发送数据报，接受 QByteArray 对象。QAbstractSocket::SocketState state() const返回套接字的当前状态。QAbstractSocket::SocketType socketType() const返回套接字的类型。bool isValid() const如果套接字有效，则返回 true；否则返回 false。int error() const返回套接字的当前错误代码。QHostAddress localAddress() const返回本地地址。quint16 localPort() const返回本地端口。int readBufferSize() const返回读取缓冲区的大小。void setReadBufferSize(int size)设置读取缓冲区的大小。QNetworkInterface multicastInterface() const返回多播组的网络接口。void setMulticastInterface(const QNetworkInterface &iface)设置多播组的网络接口。bool hasPendingDatagrams() const如果有待读取的数据报，则返回 true；否则返回 false。bool isReadable() const如果套接字可读，则返回 true；否则返回 false。bool isWritable() const如果套接字可写，则返回 true；否则返回 false。bool setSocketDescriptor(int socketDescriptor, QUdpSocket::SocketState socketState = ConnectedState, QIODevice::OpenMode openMode = ReadWrite)设置套接字描述符。int socketDescriptor() const返回套接字描述符。bool waitForReadyRead(int msecs = 30000)等待套接字可读取数据。bool waitForBytesWritten(int msecs = 30000)等待套接字已写入指定字节数的数据。void ignoreSslErrors(const QList &errors)忽略 SSL 错误。void abort()强制关闭套接字。QNetworkProxy proxy() const返回套接字的代理设置。void setProxy(const QNetworkProxy &networkProxy)设置套接字的代理设置。QString errorString() const返回套接字的错误消息字符串。