GUI File linking is when a button in one GUI file forces iViewer to load an additional GUI file.

The first time a linked GUI file is loaded, it must be served by a HTTP server. Then it is stored in cache on your mobile device.

If the iViewer setting Reload GUI Layout is turned off, the GUI is loaded from cache and won't need to be downloaded again.

Simply enter the URL to the GUI file into the URL parameter of button properties, replacing http:// with cf://.

You can also link between GUI files that are stored in the same folder using the guiDesigner Upload Service.
The GUI files must be in the same folder, and then you can use your upload service URL as the base URL and append the other GUI filename to the end.

For example, if the upload service URL was http://192.168.0.10:8019 then the special URL used to link between GUIs via button presses would look like this:
cf://192.168.0.10:8019/yourGUIFile.gui - replace 'yourGUIFile.gui' with the filename of the project you want to link to.