How to take a screenshot of the current widget - Flutter

Question

I need to take a screenshot of the current screen or widget and I need to write it into a file.

Answer 1

This answer applies if you want to take a screenshot of the widget outside of your dart code.

To take a screenshot of your widget, make sure your dart file has a void main() async { function.

From the terminal, go to your app folder, and run your widget, like this:

flutter run lib/my_test.dart

Or if you want to run your entire app, just run:

flutter run

Then your widget will start.

Press the s key to print a screenshot.

You will see a message like this:

Taking screenshot for SM S757BL... 1,580ms Screenshot written to flutter_01.png (38kB).

The image is saved in your app folder.

Answer 2

I tried and found the solution,

import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:typed_data';
import 'dart:ui' as ui;
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';
import 'package:path_provider/path_provider.dart';
import 'dart:io';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);
  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  static GlobalKey previewContainer = new GlobalKey();
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {

    return RepaintBoundary(
        key: previewContainer,
      child: new Scaffold(
      appBar: new AppBar(

        title: new Text(widget.title),
      ),
      body: new Center(
        child: new Column(

          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            new Text(
              'You have pushed the button this many times:',
            ),
            new Text(
              '$_counter',
              style: Theme.of(context).textTheme.display1,
            ),
            new RaisedButton(
                onPressed: takeScreenShot,
              child: const Text('Take a Screenshot'),
            ),
          ],
        ),
      ),
      floatingActionButton: new FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: new Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    )
    );
  }
  takeScreenShot() async{
    RenderRepaintBoundary boundary = previewContainer.currentContext.findRenderObject();
    ui.Image image = await boundary.toImage();
    final directory = (await getApplicationDocumentsDirectory()).path;
    ByteData byteData = await image.toByteData(format: ui.ImageByteFormat.png);
    Uint8List pngBytes = byteData.buffer.asUint8List();
    print(pngBytes);
    File imgFile =new File('$directory/screenshot.png');
    imgFile.writeAsBytes(pngBytes);
  }
}

Finally check your application directory You will find screenshot.png !!

Answer 3

let's say you want to take a screenshot of the FlutterLogo widget . wrap it in a RepaintBoundary with will creates a separate display list for its child . and provide with a key

var scr= new GlobalKey();
RepaintBoundary(
         key: scr,
         child: new FlutterLogo(size: 50.0,))

and then you can get the pngBytes by converting the boundary to an image

takescrshot() async {
  RenderRepaintBoundary boundary = scr.currentContext.findRenderObject();
  var image = await boundary.toImage();
  var byteData = await image.toByteData(format: ImageByteFormat.png);
  var pngBytes = byteData.buffer.asUint8List();
  print(pngBytes);
  }

Answer 4

You can use screenshot plugin to take a widget screenshot.

A screenshot is a simple plugin to capture widgets as Images. This plugin wraps your widgets inside RenderRepaintBoundary

Use this package as a library

1. Add this to your package's pubspec.yaml file:

   dependencies:
     screenshot: ^0.2.0
   

2. Now in your Dart code, Import it:

   import 'package:screenshot/screenshot.dart';
   

This handy plugin can be used to capture any Widget including full-screen screenshots & individual widgets like Text().

3. Create Instance of Screenshot Controller

   class _MyHomePageState extends State<MyHomePage> {
     int _counter = 0;
     File _imageFile;
   
     //Create an instance of ScreenshotController
     ScreenshotController screenshotController = ScreenshotController(); 
   
     @override
     void initState() {
       // TODO: implement initState
       super.initState();
     }
   ...
   }
   

4. Wrap the widget that you want to capture inside Screenshot Widget. Assign the controller to screenshotController that you have created earlier

   Screenshot(
     controller: screenshotController,
     child: Text("This text will be captured as image"),
   ),
   

5. Take the screenshot by calling the capture method. This will return a File

   screenshotController.capture().then((File image) {
    //Capture Done
    setState(() {
        _imageFile = image;
    });
   }).catchError((onError) {
    print(onError);
   });