[英]custom QAbstractNetworkCache implementation; QAbstractNetworkCache::insert(QIODevice *device) device has no data
[英]Writing custom QIODevice with 2 channels
我正在嘗試實現自定義QIODevice。
我有一個檢測器,它將使用2個tcp套接字,一個用於發送命令和接收響應,另一個用於讀取數據。
我該怎么辦? 我試圖創建我的類,從QIODevice派生它並實現純虛擬方法,但是我遇到了一些麻煩。
我有以下代碼:
class Detector : public QIODevice {
Q_OBJECT
Q_DISABLE_COPY(MasterDevice)
public:
enum CHANNEL_TYPE {
DataChannel,
ControlChannel
};
private:
QTcpSocket *controlDevice;
QTcpSocket *dataDevice;
QHostAddress hostAddress;
quint16 dataPort;
quint16 controlPort;
public:
explicit Detector(QObject *parent, QHostAddress hostAddress, quint16 dataPort, quint16 controlPort)
: QIODevice(parent)
, hostAddress(hostAddress)
, dataPort(dataPort)
, controlPort(controlPort)
{
controlDevice = new QTcpSocket(this);
connect(controlDevice, SIGNAL(readyRead()),this, SLOT(controlChannelReadReady()));
dataDevice = new QTcpSocket(this);
connect(dataDevice, SIGNAL(readyRead()),this, SLOT(dataChannelReadReady()));
}
virtual ~Detector() {}
bool open(OpenMode mode) override {
QIODevice::open(mode);
controlDevice->connectToHost(hostAddress, controlPort, QTcpSocket::ReadWrite);
dataDevice->connectToHost(hostAddress, dataPort, QTcpSocket::ReadOnly);
}
qint64 readData(char *data, qint64 maxSize) override {
QTcpSocket *socket;
switch ( currentReadChannel() ) {
case DataChannel:
socket = dataDevice;
break;
case ControlChannel:
socket = controlDevice;
break;
default:
return -1;
break;
}
return socket->read(data, maxSize);
}
qint64 writeData(const char * data, qint64 maxSize) override {
QTcpSocket *socket;
switch ( currentWriteChannel() ) {
case DataChannel:
socket = dataDevice;
break;
case ControlChannel:
socket = controlDevice;
break;
default:
return -1;
break;
}
return socket->write(data, maxSize);
}
private slots:
void controlChannelReadReady() {
emit channelReadyRead(ControlChannel);
}
void dataChannelReadReady() {
emit channelReadyRead(DataChannel);
}
};
所以基本上我的問題是,我該如何處理這些渠道,因為例如從qt documentation
我有這個
bool QIODevice::open(OpenMode mode)
打開設備並將其OpenMode設置為mode。 如果成功,則返回true;否則,返回true。 否則返回false。 任何重新實現的open()或其他打開設備的函數都應調用此函數。
因此,我必須從重寫的Open()
方法中調用它,但是我查看了此方法的實現,發現該方法將通道數設置為1。如何更改此數字?
我要從QIODevice繼承的那些緩沖區是什么,該如何使用它們?
我是否缺少創建自定義QIODevice的意義? 如果是這樣,請向我解釋。
您可能不需要在這里將QIODevice
子類QIODevice
,只需使用所需的語義來設計和實現接口,例如:
sendCommand();
responseReceived();
dataReady();
...
etc
QIODevice
是一個通用接口,用於從/向不同的源(例如文件,套接字,串行端口等)讀取/寫入字節流。
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