addListener method Null safety Adds a listener callback that is called whenever a new concrete ImageInfo object is available or an error is reported . If a concrete image is already available, or if an error has been already reported, this object will notify the listener synchronously.
Read moreHow do you update value in flutter?
To update the value of data points, re-initialize the data source collection and use the setState() method . In the following example, we have called the setState() method in the onPressed() event of a button. For more information, refer to the Updating the Existing Flutter Chart Data Point Value project demo.
Read moreWhat is ValueNotifier flutter?
ValueNotifier is a special type of class that extends Changenotifier, which can hold a single value and notifies the widgets which are listening to it whenever its holding value gets change .15 Eki 2021
Read moreWhat is ValueListenableBuilder?
ValueListenableBuilder will listen for changes to a value notifier and automatically rebuild its children when the value changes . If you have more complex data, create a custom notifier for your data classes by extending ValueNotifier.
Read moreWhat is value notifier flutter?
ValueNotifier is a special type of class that extends Changenotifier , which can hold a single value and notifies the widgets which are listening to it whenever its holding value gets change.
Read moreWhat is the alternative of setState in Flutter?
The short answer is that just add currentIndex as one of the parameter inside your navBarSection . Inside home. dart , just pass the currentIndex of the page.
Read moreWhat is Valuelistenablebuilder in Flutter?
A widget whose content stays synced with a ValueListenable . Given a ValueListenable<T> and a builder which builds widgets from concrete values of T , this class will automatically register itself as a listener of the ValueListenable and call the builder with updated values when the value changes.
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