Aug. 28, 2016, 11:17 a.m.

Qt

Qt, C++, lambda, QSignalMapper, лямбда функция

QSignalMapper is a wonderful class to organize the work of the signals and slots dynamically created objects. For example, the dynamically created buttons or objects in QStackedWidget. This was particularly true in older versions of the software, that is, and relied on Qt 4.8, which signals and slots system was based on the use of macros. But in the current realities of the new syntax in the indexes is much more convenient, and also supports a lambda function that can afford and does get rid of the application QSignalMapper, which will look like a monstrous throwback to new projects that use the latest version of the framework Qt and C++ language standards.

And when you consider more and congestion map() and mapped(), then it does with QSignalMapper code even more terrible, if used to connect signals and slots with the use of pointers, since it is necessary to cast the signals and slots, but more on that later.

Therefore, let us consider a small project that will be based on the example of the official documentation of Qt. Namely, an example will next. We have QLabel, QPushButton and Vertical Layout . By pressing a button in the Vertical Layout will be added to other dynamic buttons, by clicking on which QLabel will display the text from the button number in the following form: "Button 2". In the following figure shows an example of the application whose appearance will not differ, while the software implementations of the code will be a few.

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a
Feb. 25, 2020, 5:40 a.m.
ayb

C++ - Test 005. Structures and Classes

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DZ
Feb. 24, 2020, 2:47 p.m.
Dmitrij Zlobin

C ++ - Test 004. Pointers, Arrays and Loops

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p
Feb. 17, 2020, 2:41 p.m.
pstMem

C++ - Тест 003. Условия и циклы

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Last comments
Feb. 24, 2020, 3:54 a.m.
Evgenij Legotskoj

Добрый день. Там будет url, на который указывает ссылка тега a в пагинаторе, если правильно помню )) Написал этот код и забыл.
B
Feb. 24, 2020, 12:37 a.m.
BahaMeirman

Евгений Здравствуйте! Не могу понять вот эту часть кода: url: jQuery(this).attr('action') наверное здесь должен быть путь к url, тогда 'action' на какой url указывает?
Feb. 17, 2020, 3:22 a.m.
Evgenij Legotskoj

Добрый день. Это кастомный тег, помещается в файл, который находится в каталоге templatetags myapp/ templatetags/ myapp.py
B
Feb. 16, 2020, 1:36 p.m.
BahaMeirman

Добрый вечер! Монжно по подробней о теге get_companion? ссылка не работает.
Now discuss on the forum
a
Feb. 25, 2020, 8:06 a.m.
ayb

Да
Feb. 24, 2020, 12:04 p.m.
Evgenij Legotskoj

Добрый день. Вот пример с дружественного ресурса с движением камеры
Feb. 24, 2020, 6:29 a.m.
Evgenij Legotskoj

Qt не предоставляет функционала по запросу root прав во время выполнения программы. Поэтому нужно использовать платформозависимый функционал, для Linux это будет выглядеть так: #include…
Feb. 24, 2020, 3:47 a.m.
Evgenij Legotskoj

Добрый день. Что означает клиентская область? Это изображение? Вам нужно распознавать символы текста или всё-таки пользователь будет вводить текст с клавиатуры, просто в любом месте "абстр…
VZ
Feb. 21, 2020, 5:19 a.m.
Vladimir Zhitkovsky

void sendImage(int sessid, int type, int dest, int format, QString imgBase64Data){ QNetworkRequest request; request.setUrl(QUrl(ipAddress + "ctlapi/cmd=preparereportimg&sessid=…
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