State Triggers
Explore how to implement state triggers in .NET MAUI to enable dynamic UI updates based on changes in screen orientation, window size, or device state. Understand different trigger types such as OrientationStateTrigger and AdaptiveTrigger, and learn how to define VisualStateGroups to control layout and behavior, enhancing the responsiveness of your cross-platform applications.
We'll cover the following...
State triggers are fired when the state of some element changes. For example, we might have a trigger that monitors the screen orientation. The setter on the trigger will then rearrange the elements depending on whether the screen is in portrait or landscape mode. There might also be a trigger that monitors the state of a specific property on a specific element. For example, we might have a trigger that monitors the dimensions of the app window and hides some elements when it becomes too small. There are multiple types of state triggers in .NET MAUI, but they all follow similar principles.
We'll cover state triggers in .NET MAUI with the aid of the following project setup:
<?xml version = "1.0" encoding = "UTF-8" ?>
<Application xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:StateTriggerDemo"
x:Class="StateTriggerDemo.App">
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Resources/Styles/Colors.xaml" />
<ResourceDictionary Source="Resources/Styles/Styles.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
Adding a state trigger to a page
In the example above, we add global state triggers to the ContentPage.Resources element on lines 6–33 of the MainPage.xaml file. This is because we change the state ...