Accessibility order on Xamarin
Assistive technologies try to determine a logical accessibility order based on the placement and properties of the elements on the screen. In Left-to-Right languages, the order goes from top to bottom, from left to right. If this order is not optimal, you can override the accessibility order that assistive technologies follow.
Xamarin Forms supports changing the accessibility order through the TabIndex property. The default value is 0. The lower the value, the higher the priority. For example, to reach the save button before reaching the cancel button, the cancel button's TabIndex needs to be higher than the save button.
<Label Text="Appt" />
<Button x:Name="cancelButton" TabIndex="20" />
<Button x:Name="saveButton" TabIndex="10"/>