Flutter - Show alert dialog after StreamBuilder loaded data and UI

Question

I want to show an alert dialog after I get data from StreamBuilder. I also have a UI to render. Currently, I'm having an error like this when I'm trying to build dialog inside _loadUI method before returning actual UI.

setState() or markNeedsBuild() called during build.

Code:

if (dataSnapshot.hasData) {
            return dataSnapshot.data ? _loadUI(dataSnapshot.data) : _emptyView();
          }

Answer 1

You can do like this:

void _loadUI(snapshot) {
...

  WidgetsBinding.instance.addPostFrameCallback((_){
    showDialog(
      context: context, 
      ...
    );
  });
}

addPostFrameCallback run during a frame, just after the persistent frame callbacks (which is when the main rendering pipeline has been flushed).