Triggers take a trigger source such as an event and then can change a property on that control in response to the trigger. The basic principle is, a trigger is activated and you set properties or invoke code. Below are the following triggers you can use.
- Property
- Data
- Event
- Multi Trigger
Documentation: Working with Triggers
Example Use Case: Update the Background Color of Entry control when IsFocused becomes true.
public class BackgroundColorTrigger : TriggerAction<Entry> { protected override void Invoke(Entry sender) { sender.BackgroundColor = Color.Yellow; } }Then we can apply it to an Entry Control and define what triggers the trigger.
// Add to Page Attributes (Above Trigger is in Namespace Mobile.Trigger) xmlns:trigger="clr-namespace:Mobile.Trigger" <Entry Text="{Binding EntryField}"> <Entry.Triggers> <EventTrigger Event="Focused"> <trigger:BackgroundColorTrigger /> </EventTrigger> </Entry.Triggers> </Entry>Ref
https://docs.microsoft.com – https://xamarinhelp.com – https://blog.xamarin.com/