Designer - UIファイルまたはコードによるGUIを書く最善の方法は何ですか？
I'm beginner to Qt and I see that most of widgets that are build in in Qt do not appear in the widgets tool box.
How can I add all the widget to tool box? (Like
QSystemTrayIcon that does not appear by default in tool box)
what is the best way to write gui - by the designer - ui file or by code - cpp file?
The designer just shows widgets which are displayed in a window. It doesn't make sense to 'design' a QSystemTrayIcon in a window design tool. Just create it from code during startup.
Wether you write the UI code by hand or use the designer is really up to you. Speaking of me, I consider Qt's designer a very mature tool that helps designing my user interfaces quickly. So yes, I use it...</div
I would advice to not use designer, in order to work with a pure c++ code and do not deal with some qt code generations. It is flexible approach in my opinion, though, I guess, lot of people use Qt designer, and even like it. So this is something personal. But, honestly, I used Qt designer when I was a beginner. Configuring widgets with a visual editor was a great help for me. No I prefer only coding.
WRT adding the widgets you listed - no it is not possible. You should instantiate them manually.</div