How to call a function to update a value after popping a screen in Flutter?

user_9328725 0
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Screen 1: shows list of item with add button. Screen 2: form to add a new item to the list.

Screen 2 >> Screen 1 - While calling navigator.pop() in screen 2, how to call method/setState (to update list) in screen 1? Can anyone help me out?

I don't want to relaunch screen again. I just need to run a method to update my list after popping previous screen?

flutter-layout dart flutter mobile
4 Answers

When you navigate from Screen 1 to Screen 2, you use the push method. The push method returns a Future object. You can use the then method of Future to execute your code after Screen 2 was popped from the navigation stack.

Navigator.of(context)
  .push(MaterialPageRoute(
     builder: (context) => Screen2(),
  ))
  .then((value) {
    // you can do what you need here
    // setState etc.
  });
user_49044540

You can use Provider or BLoc or you can await for the result when you push the page

user_44140450

Navigator.pop has a second argument called result. You could then return the value that you need to the first page that will read it as the return value of Navigator.push

user_81715510

You can do it like this :

// this method waits for the pop to be called
var data = await Navigator.push(
  context,
  MaterialPageRoute(builder: (context) => LoginScreen()),
);

debugPrint(data); 

// here the second argument is the data 
Navigator.pop(context, "data");  // popped from LoginScreen().

output

data

Same method can also be done like below

   // this method waits for the pop to be called
Navigator.push(
  context,
  MaterialPageRoute(builder: (context) => LoginScreen()),
).then((data){
    // then will return value when the loginScreen's pop is called.
    debugPrint(data); 
});

Here is a good article to look into this https://medium.com/flutter-community/flutter-push-pop-push-1bb718b13c31

user_58305510
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