Once you have activated Visual Forms for your project you have 2 options to keep your captures in sync with the continual changes you make to your project. 

Manual 

The default mode for keeping forms in sync is manual. Manual mode means you determine when you want to update the captures of your forms. 

When manual mode is selected you can update the form by selecting the Capture Form menu item in the Visual Forms sub menu accessible from the View menu. You can also use the Refresh Selected toolbar button (or context menu item) on the Visual Forms Main Window. 

The form doesn't have to be visible when using either of these updating commands. You could have the code editor active at this time. 

Automatic after saving 

When you make changes to a form and save them the capture automatically updates as well. Depending on your capture options, this may involve changing the current editor view back to the designer. As some users may find this distracting (even though it is generally a very swift process) this update mode is off by default. 

You can also be prompted before updating the capture if you desire. This prompt can be disabled in the Options dialog in the Capture section.