QT add library (static library and dynamic library)
The method of adding dynamic library (dll library): **
It is to put all the required dll libraries into the folder where the exe is located, in the same level directory as the exe .
The method of adding a static library (lib library):
1. Right-click the project file, click Add Library
2. Select an external library
3. Perform the following configuration, 
4. Click Next and click Finish. If an error is reported when running, you need to comment out the last line of else code that adds the code automatically generated by each library in the pro file.