Visual Studio说这里是错误C2665。但是为什么呢？我100%确定我的代码是正确的。QComboBox有一个只接受一个int参数的信号currentIndexChanged。我有一个只接受一个int参数的插槽。那么连接它们有什么问题呢？
//Defined in ui_MyDialog.h
QComboBox *messageType;
...
//Constructor of MyDialog
connect(ui.messageType, &QComboBox::currentIndexChanged, this, &MyDialog::IndexChanged, Qt::QueuedConnection);
...
//Prototype of signal in MyDialog class definition
public slots:
void IndexChanged(int index);
...
//Definition of IndexChanged signal
void MyDialog::IndexChanged(int index)
{
}错误文本：
1>MyDialog.cpp(61,119): error C2665: QObject::connect: none of the 3 overloads can convert all argument types
1>F:\Qt\5.15.2\msvc2019_64\include\QtCore\qobject.h(225,36): message : can be "QMetaObject::Connection QObject::connect(const QObject *,const QMetaMethod &,const QObject *,const QMetaMethod &,Qt::ConnectionType)" (source file MyDialog.cpp is compiled)
1>F:\Qt\5.15.2\msvc2019_64\include\QtCore\qobject.h(222,36): message : or "QMetaObject::Connection QObject::connect(const QObject *,const char *,const QObject * ,const char *,Qt::ConnectionType)" (compiles source file MyDialog.cpp)
1>MyDialog.cpp(61,5): message : "QMetaObject::Connection QObject::connect(const QObject *,const char *,const QObject *,const char *,Qt::ConnectionType)": cannot convert argument 2 from "overloaded-function" to "const char *"
1>MyDialog.cpp(61,41): message : Context does not allow overloaded function disambiguation
1>F:\Qt\5.15.2\msvc2019_64\include\QtCore\qobject.h(222,36): message : see "QObject::connect" declaration (source file MyDialog.cpp is compiled)
1>MyDialog.cpp(61,119): message : when trying to match argument list "(QComboBox *, overloaded-function, MyDialog *, void (__cdecl MyDialog::* )(int), Qt::ConnectionType)"
1条答案
按热度按时间osh3o9ms1#
编译器对插槽和信号一无所知，所以它不会比较插槽签名和信号签名。如果某个插槽或信号有重载，指向这个插槽的链接或指针将是不明确的。为了避免这种情况，我们需要显式指定我们在这里使用的重载方法，使用
QOverload。连接此信号的正确方法：