How to use the Charm button of Win10 system?

In the Windows 10 Technology Preview, Microsoft added the “Share” button in the toolbar sharing of File Explorer (the first black share button in the title map). The following small series tells you how to use the Win10 system share button. As long as you select the appropriate file in the file manager, click the "share” button to open the shared Charm on the right.

For example, if you choose an image file, click Share to send it as an email attachment, or share it to Facebook or Twitter (provided you install these apps). Microsoft said that this feature is still in its early stages and needs to be improved. If you are a developer, you can pay attention to the development of Share Contract.
The current Win10 feature relies heavily on shared Charm, which Microsoft says will continue to improve the Charm interface. Also, clicking twice from the toolbar to share is a bit more than that.