Flutter: Show Loading Dialog [Easy Method]

Loading dialog is useful for user experience. It is used to show users that something is happening at the backend.

For example

You are loading data from the server to the user’s device by using an API. Now, this process will take some time. And you can show a loading indicator. And users feel totally OK and wait for the data that will eventually show on the screen.

You can also use a loading UI when you are saving data to any database.

These processes are known as asynchronous operations because they take time. And we show some kind of indicator for these computations.

Let’s see how you can create your own loading indicator for async processes.

Example: Flutter Loading Dialog

In this app, you will see a simple flutter app that shows a dialog when we press the center save button.

App Preview:

App Code:

import 'package:flutter/material.dart';
void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(primarySwatch: Colors.green),
      debugShowCheckedModeBanner: false,
      home: const LoadingDialogScreen(),
    );
  }
}

class LoadingDialogScreen extends StatefulWidget {
  const LoadingDialogScreen({Key? key}) : super(key: key);

  @override
  State<LoadingDialogScreen> createState() => _LoadingDialogScreenState();
}

class _LoadingDialogScreenState extends State<LoadingDialogScreen> {
  void _saveData(BuildContext context) async {
    showDialog(
        barrierDismissible: false, //Don't close dialog when click outside
        context: context,
        builder: (_) {
          return Dialog(
            backgroundColor: Colors.white,
            child: Padding(
              padding: const EdgeInsets.symmetric(vertical: 50),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: const [
                  CircularProgressIndicator(), //Loading Indicator you can use any graphic
                  SizedBox(
                    height: 20,
                  ),
                  Text('Saving...')
                ],
              ),
            ),
          );
        });

    //Perform your async operation here
    await Future.delayed(const Duration(seconds: 3));

    Navigator.of(context).pop(); //Close the dialog
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        centerTitle: true,
        title: const Text('codewithhussain.com'),
      ),
      body: Center(
        child: ElevatedButton.icon(
          icon: const Icon(Icons.save),
          onPressed: () => _saveData(context),
          label: const Text('Save'),
        ),
      ),
    );
  }
}