Use Dialog to configure the font selection dialog before the action fires or to read the selected font after the action executes the dialog. For example, you can set the font dialog's target device or limit the available font sizes at design time using the Object Inspector or read the Font property in an OnAccept event handler to make use of the font that the user selects. 

When using a font edit action, you do not place a TFontDialog component on the form or data module at design time. Instead, you add the TFontEdit to your action list and then use the Dialog property. The font selection dialog component is created by the TFontEdit constructor. 

OnAccept 

OnCancel 

Font