Try It Yourself

The interactive playground at the end of this lesson contains a .NET MAUI project that was set up with various types of triggers and action classes associated with them. We can apply the following modifications to it and see how they would affect the structure of the compiled application:

  • Applying a property trigger.

  • Adding a data trigger.

  • Applying an event trigger.

  • Applying a device state trigger.

  • Applying changes to the EnterActions and ExitActions triggers.

Applying a property trigger

In the setup at the end of this lesson, we have two Entry elements. The second element doesn't have any triggers. We'll need to apply a property trigger to it that will set the Background property of this element to Green when focused.

Adding a data trigger

Next, we'll apply another trigger to the second Entry element. The trigger will use the first Entry element as its BindingSource. To enable such a relationship, we would need to add the x:Name attribute to the first Entry element.

The data trigger will read the Length property of the Text field of the first Entry element. If the first element is empty (i.e., if the Length value is 0)the second Entry element should be disabled. This can be achieved by setting the IsEnabled property to False inside the trigger's Setter.

Applying an event trigger

We'll now add another Entry element and add an EventTrigger element to it. We'll associate the trigger with the TextChanged event. The ChangeTextColorAction will represent the trigger action.

Applying a device state trigger

In the MainPage.xaml file in the setup at the end of the lesson, we have orientation state triggers that will toggle between the horizontal and vertical alignment of the elements on the screen, depending on whether the screen is in the portrait or landscape orientation. Let's now change our original OrientationStateTrigger to DeviceStateTrigger. This is how it can be set:

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