Gets or sets the visual position of the current custom button within the combined list of the built-in and custom buttons.
A zero-based value that specifies the visual position of the current custom button within the combined list of the built-in and custom buttons. -1 if the custom button is displayed at the end of this list.
When custom buttons are added to the NavigatorButtonsBase.CustomButtons collection, the navigator control displays them after the built-in buttons (NavigatorButtonsBase.ButtonCollection), by default. Use the Index property to change the visual position of custom buttons.
Before displaying buttons, the navigator control creates a combined list of the built-in and custom buttons. First, it adds the built-in buttons to this list. Then, custom buttons are inserted to this list according to their Index property values. For instance, if a custom button has the Index property set to 1, this button is inserted at the second position (indexes are zero-based). If the Index property is set to -1, this custom button is added at the end of the combined list. Thus, the Index property allows you to insert custom buttons before the built-in buttons or between them.