QT信号槽总结-connect函数错误用法
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QT库的qobject.h
connect函数声明：connect函数用于建立信号与槽之间的连接，QT库提供了三种实现：
static QMetaObject::Connection connect(const QObject *sender, const char *signal,
const QObject *receiver, const char *member, Qt::ConnectionType = Qt::AutoConnection);
static QMetaObject::Connection connect(const QObject *sender, const QMetaMethod &signal,
const QObject *receiver, const QMetaMethod &method,
Qt::ConnectionType type = Qt::AutoConnection);
inline QMetaObject::Connection connect(const QObject *sender, const char *signal,
const char *member, Qt::ConnectionType type = Qt::AutoConnection) const;
class ConnectCamera : public QWidget
{
Q_OBJECT
public:
ConnectCamera(QWidget *parent = Q_NULLPTR);
~ConnectCamera();
public slots:
void onConnectBtnSolt();
void onCancelBtSolt();
void onErrorMess(const QString & _errorMess);
signals:
void signalConnectCamera(const QString& _ip, const QString& _user, const QString& _pass);
private:
Ui::ConnectCamera ui;
};
使用QT库提供的第一种实现方式，来绑定信号与槽
正确用法1：
connect(ui.okButton, SIGNAL(clicked()), this, SLOT(onConnectBtnSolt()));
connect(ui.cancelButton, SIGNAL(clicked()), this, SLOT(onCancelBtSolt()));
错误用法1：
connect(ui.okButton, SIGNAL(clicked()), this, SLOT(onConnectBtnSolt));
原因分析：
用法1调用的connect函数实际为：
static QMetaObject::Connection connect(const QObject *sender, const char *signal,
const QObject *receiver, const char *member, Qt::ConnectionType = Qt::AutoConnection);
// SLOT的定义
Q_CORE_EXPORT const char *qFlagLocation(const char *method);
# define SLOT(a) qFlagLocation("1"#a QLOCATION)
qt中的信号槽，实际用的是回调函数，onConnectBtnSolt（）被解析为函数，onConnectBtnSolt格式判断会出错
网上很详细的讲解，QT版本可能早于5.9.6
QT QObject：：connect函数的学习
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