asImage method
Implementation
Future<ImageData> asImage() async {
RenderRepaintBoundary boundary =
globalKey.currentContext!.findRenderObject() as RenderRepaintBoundary;
ui.Image image = await boundary.toImage(pixelRatio: 6.0);
ByteData? byteData = await image.toByteData(format: ui.ImageByteFormat.png);
Uint8List pngBytes = byteData!.buffer.asUint8List();
return img.decodePng(Uint8List.view(pngBytes.buffer))!;
}