共享和打印屏幕 Flutter

Question

import 'dart:io';
import 'dart:typed_data';
import 'package:cached_network_image/cached_network_image.dart';
import 'package:esys_flutter_share/esys_flutter_share.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';

Imports...

  screenshot: ^0.2.0
  esys_flutter_share: ^1.0.2

I only need to take a capture, and then share it I am using the following code but I receive the error:

    _takeScreenshotandShare() async {
    _imageFile = null;
    screenshotController
        .capture(delay: Duration(milliseconds: 10), pixelRatio: 2.0)
        .then((File image) async {
      setState(() {
        _imageFile = image;
      });
      final directory = (await getApplicationDocumentsDirectory()).path;
      Uint8List pngBytes = _imageFile.readAsBytesSync();
      File imgFile = new File('$directory/screenshot.png');
      imgFile.writeAsBytes(pngBytes);
      print("File Saved to Gallery");
      await Share.file('Anupam', 'screenshot.png', pngBytes, 'image/png');
    }).catchError((onError) {
      print(onError);
    });
  }

My mistake is:

I/flutter ( 2486): NoSuchMethodError: The method 'findRenderObject' was called on null.
I/flutter ( 2486): Receiver: null
I/flutter ( 2486): Tried calling: findRenderObject()

Answer 1

I face the same issue with screenshot package so my workaround is call same function again incase of error occur.

screenshotController.capture().then((File image) async {
      Uint8List pngBytes = image.readAsBytesSync();
      final directory = (await getApplicationDocumentsDirectory()).path;
      File imgFile = new File('$directory/${DateTime.now().millisecondsSinceEpoch}.png');
      await imgFile.writeAsBytes(pngBytes);
      if(pngBytes.length == 0)
        // call Same function again
      else 
       // your image
    }).catchError((onError) {
      print(onError);
      Future.delayed(Duration(seconds: 1)).then((value) => //call Same function again);
    });