Raised when changes occur which may affect the control's UI.
The UpdateUI event's data class is EventArgs.
This event signalizes that Bar or Ribbon user interface of the PDF Viewer is updated to reflect changes in the control's state. Certain commands may change their state from enabled to disabled, from visible to hidden and vice versa.
This event occurs:
- When the control gets focus or the focus is lost;
- When the current selection is changed;
- When the content of the control is changed;
- When its status (modified or read-only) is modified.