change background color of container with animation when app is running in flutter

Question

I want to change the background color of container with animation infinitely. I know that i can do that using AnimatedContainer like below code:

AnimatedContainer(
 duration: Duration(seconds: 2),
 color: _color,
 curve: Curves.fastOutSlowIn,
 height: 200,
 width: 200,
),
FlatButton(
 child: Text('Change Color'),
 onPressed: (){
   setState((){
     _color= Colors.red;
   });
 },
),

but i dont want to change the color and setState using press a button. I want to change it when the app start runnig, without press anything. How can i achieve this?

I think i must setState after changing value of color but i dont know how to setState without click on something.

also i did this:

AnimatedContainer(
 color: animatedBackgroundColor,
 duration: Duration(seconds: 2),
 onEnd: () => setState(() {
  animatedBackgroundColor = const Color.fromARGB(255, 197, 14, 14);
 }),
)

but it didnt change anything. I think that after the widget is created and its color is set, a button should be clicked at least once to change the animatedBackgroundColor and then the animation starts. but i want it without button click and start change from current color to the color i set in onEnd.

Answer 1

You can do something like this

@override
  void initState() {
    super.initState();
    // Start a timer to change the color after 2 seconds
    Timer(Duration(seconds: 2), () {
      setState(() {
        _color = Colors.red; // Change color to red after 2 seconds
      });
    });
  }

And in you animated container

AnimatedContainer(
            duration: Duration(seconds: 2),
            color: _color,
            curve: Curves.fastOutSlowIn,
            height: 200,
            width: 200,
            onEnd: () => setState(() { 
             animatedBackgroundColor = Colors.green;
           }),
          ),