Use Dialog to configure the graphics file selection dialog before the action fires or to read the selected file name after the action executes the dialog. For example, you can set the dialog's default extension or initially selected file at design time using the Object Inspector or read the dialog's FileName property from an OnAccept event handler to use the file that the user selected. 

When using an open picture action, you do not place a TOpenPicture Dialog component on the form or data module at design time. Instead, you add the TOpenPicture object to your action list and then use the Dialog property. The dialog component is created by the TOpenPicture constructor. 

onaccept 

oncancel 

FileName