你不对。少了数据库模块的引入
时间: 2023-08-12 22:04:35 浏览: 38
非常抱歉,我漏掉了数据库模块的引入。下面是修正后的代码:
```cpp
#include <QtNetwork>
#include <QtSql>
class TcpClient : public QObject
{
Q_OBJECT
public:
TcpClient(QObject *parent = nullptr) : QObject(parent)
{
connect(&m_socket, &QTcpSocket::connected, this, &TcpClient::onConnected);
connect(&m_socket, &QTcpSocket::disconnected, this, &TcpClient::onDisconnected);
connect(&m_socket, QOverload<QAbstractSocket::SocketError>::of(&QTcpSocket::errorOccurred),
this, &TcpClient::onErrorOccurred);
connect(&m_timer, &QTimer::timeout, this, &TcpClient::onTimeout);
}
public slots:
void connectToServer(const QString &host, quint16 port, int timeout)
{
m_host = host;
m_port = port;
m_timeout = timeout;
m_socket.connectToHost(m_host, m_port);
m_timer.start(m_timeout);
}
signals:
void connected();
void disconnected();
void errorOccurred(QAbstractSocket::SocketError error);
void timeout();
private slots:
void onConnected()
{
m_timer.stop();
emit connected();
}
void onDisconnected()
{
emit disconnected();
}
void onErrorOccurred(QAbstractSocket::SocketError error)
{
emit errorOccurred(error);
}
void onTimeout()
{
m_socket.abort();
emit timeout();
}
private:
QTcpSocket m_socket;
QTimer m_timer;
QString m_host;
quint16 m_port;
int m_timeout;
};
```
在这个代码中,我们增加了`#include <QtSql>`语句,以引入数据库模块。同样的,使用TcpClient类的代码也需要增加对数据库模块的引入。
```cpp
#include <QtSql>
//...
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
//...
QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
db.setHostName("localhost");
db.setDatabaseName("mydb");
db.setUserName("user");
db.setPassword("password");
if (!db.open()) {
qDebug() << "Failed to connect to database";
return 1;
}
//...
return a.exec();
}
```
在这个代码中,我们使用`QSqlDatabase`类来连接MySQL数据库。首先调用`QSqlDatabase::addDatabase`函数添加MySQL数据库驱动,然后设置数据库主机名、数据库名、用户名和密码,最后调用`QSqlDatabase::open`函数来连接数据库。如果连接失败,将会输出一条错误信息。