Today, we’ll talk about the “simplest” class of Qt, a class we use every day, a class we often do need to care about the details – QString. Despite the […]

Suppose you have a myprogrammingnotes.dll that contains a COM object. You want to instantiate and use that COM object in your Qt app. How to do that? If myprogrammingnotes.dll contains […]

When running “regsvr32 some.dll”, what keys/names/values are added in the registry?(note that regsvr32 can register both 32bit dll and 64 bit dll on 64bit Windows) Computer\HKEY_CLASSES_ROOT\yourapp.YOURCLASSBinder\ CLSID CurVer Computer\HKEY_CLASSES_ROOT\yourapp.YOURCLASSBinder.1\ CLSID […]

You must know how to use QSslSocket::supportsSsl in your app to check if your Qt lib supports ssl. How does QSslSocket::supportsSsl decide if it supports ssl or not? The function […]

As an old programmer, when I debug a program, the first option is neither using qDebug()<<“helloworld”, nor using cout<<“helloworld”, not mention QMessageBox::information(this,”hello”,”world”). I’d like to use the old printf function. […]

Look at this simple code: QString s=”abcd”; char * ts=s.toLocal8Bit().data(); QMessageBox::information(NULL,”length”,QString(“s length:%1, ts length:%2”).arg(s.length()).arg(strlen(ts))); What do you think about the length of s and ts? Are they both 4? No, […]

Yes, you really can build out the dll that contains your COM server according to this guide. But the story just begins. When you register your dll with “regsvr32 myprogrammingnotes.dll”, […]

I used to work with Qt5/Qt4, where you can open a project by clicking the .pro file in the folder of the project. But today after downloading a QT6 project, […]

Download and install software required to build Qt6 with VS To build Qt6 on Windows using Visual Studio, you need to install several software: cmake perl python3 ninja Visual Studio […]