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This article mainly introduces "how to understand the reflection mechanism". In the daily operation, I believe that many people have doubts about how to understand the reflection mechanism. The editor consulted all kinds of data and sorted out simple and easy-to-use operation methods. I hope it will be helpful for you to answer the doubts about "how to understand the reflection mechanism"! Next, please follow the editor to study!

For each derived class of the QObject class, qt uses the moc command to generate an additional moc_xxx.cpp file.

Additional information about QObject-derived classes is included in the moc_xxx.cpp file.

Define a class for Sender in the sender.h header file:

It has three signals and four slot functions respectively.

In the generated moc_sender.cpp:

Qt_meta_stringdata_Sender is a literal scale, which can also be called a symbol table.

It exists so that the corresponding string can be obtained with idx. For example, if idx = 4, the corresponding string is (const char *) (qt_meta_stringdata_Sender.stringdata0+29).

The other is qt_meta_data_Sender, which generates the following content:

As you can see from the above, the above data is sufficient to describe several signal and slot functions in the Sender class, and describe their parameters and return value types.

It is worth noting that the way to identify signals and slots is a string. Therefore, in order to cause individual problems: the Qt signal function uses the inner type of the class as a parameter, which leads to the analysis of the failure of connect.

This is also the basis of the Qt reflection mechanism.

At this point, the study of "how to understand the reflection mechanism" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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