debugNeedsPaint is not true

[mrtungdev]

Hello, just implemented this package, when I call:

final captureImage = await screenshotController.captureAsUiImage(pixelRatio: 2);
final data = await captureImage.toByteData(format: ui.ImageByteFormat.png);
return CaptureResult(data?.buffer?.asUint8List(), captureImage.width, captureImage.height);

I got this error:

E/flutter (25668): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: 'package:flutter/src/rendering/proxy_box.dart': Failed assertion: line 2958 pos 12: '!debugNeedsPaint': is not true.
E/flutter (25668): #0      ScreenshotController.captureAsUiImage.<anonymous closure>
package:screenshot/screenshot.dart:78
E/flutter (25668): #1      new Future.delayed.<anonymous closure> (dart:async/future.dart:326:39)
E/flutter (25668): #2      _rootRun (dart:async/zone.dart:1182:47)
E/flutter (25668): #3      _CustomZone.run (dart:async/zone.dart:1093:19)
E/flutter (25668): #4      _CustomZone.runGuarded (dart:async/zone.dart:997:7)
E/flutter (25668): #5      _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1037:23)
E/flutter (25668): #6      _rootRun (dart:async/zone.dart:1190:13)
E/flutter (25668): #7      _CustomZone.run (dart:async/zone.dart:1093:19)
E/flutter (25668): #8      _CustomZone.bindCallback.<anonymous closure> (dart:async/zone.dart:1021:23)
E/flutter (25668): #9      Timer._createTimer.<anonymous closure> (dart:async-patch/timer_patch.dart:18:15)
E/flutter (25668): #10     _Timer._runTimers (dart:isolate-patch/timer_impl.dart:397:19)
E/flutter (25668): #11     _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:428:5)
E/flutter (25668): #12     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:168:12)
E/flutter (25668):

Please help. Thank you.

[mrtungdev]

This error shows when I set offstage (Off screen), sometimes it works, sometimes not.

[ritheshSalyan]

@ImTung If you are rendering widget offscreen the you can make use of captureFromWidget function.

[yichaosun]

see here bro, the render tree haven't completed, not about offscreen. in old device or simulation, will happen frequency. let't do ensure the render complete

1、warp with WidgetsBinding.instance.addPostFrameCallback

    WidgetsBinding.instance.addPostFrameCallback((_) async {
      await screenshotController.capture(delay: const Duration(milliseconds: 100)).then((Uint8List? image) async {
        if (image != null) {
          final directory = await getApplicationDocumentsDirectory();
          final imagePath = await File('${directory.path}/image.png').create();
          await imagePath.writeAsBytes(image);

          logger.i("create img");
                final result =
                await ImageGallerySaver.saveImage(image);
        }
      });
    });

2、