How to use OpenFile and SaveFile dialogs

We are willing to implement the ability to start our application with a classic Open File dialog where users can browse for their files to import and use them in the running application.

We have tried to find a solution to do that but so far we couldn’t make it work. Is there any sample or documentation about such functionality?

The same applies for a regular Save File dialog where users can browse a folder on their computer and type in a name to save their content just like in a regular Windows application.

Thank you in advance for any help.