hyzp_ybqx/lib/pages/Works/DWDT/widget_to_image.dart

import 'dart:io';
import 'dart:typed_data';

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:path_provider/path_provider.dart';
import 'package:path/path.dart' as mypath;
import 'dart:ui' as ui;

Future getIconWidget(String name) async {
  // print("name length = ${name.length}");
  double _widthBtn = name.length * 40.0;
  double _text_height = 45;
  double _icon_width = 40;
  double _icon_height = 65;
  double _edge = 16;

  return Container(
    width: _widthBtn * 1.5 + _icon_width,
    height: _text_height + _icon_height,
    color: Colors.transparent,
    child: Column(
      children: [
        Container(
          width: _widthBtn,
          height: _icon_height,
          color: Colors.transparent,
          child: Directionality(
            textDirection: TextDirection.ltr,
            child: RichText(
              text: TextSpan(style: TextStyle(color: Colors.black, fontSize: 36.0), children: [
                WidgetSpan(
                    child: IconTheme(
                  data: IconThemeData(size: 64, color: Colors.red),
                  child: Icon(
                    new IconData(0xe60b, fontFamily: 'myfont', matchTextDirection: true),
                  ),
                )),
                // TextSpan(text: "\n白塔山公园", style: TextStyle(color: Colors.black, fontSize: 36.0)),
              ]),
              textAlign: TextAlign.center,
            ),
          ),
        ),
        Row(
          textDirection: TextDirection.ltr,
          children: [
            SizedBox(width: _widthBtn * 0.5 + _icon_width),
            Container(
              // margin: EdgeInsets.only(left: _widthBtn * 0.5),
              // padding: EdgeInsets.only(left: _widthBtn * 0.5),
              width: _widthBtn,
              height: _text_height,
              color: Colors.yellow,
              child: Directionality(
                  textDirection: TextDirection.ltr,
                  child: Text(name,
                      textAlign: TextAlign.center,
                      style: TextStyle(
                          color: Colors.black, fontWeight: FontWeight.bold, fontSize: 36.0))),
            ),
          ],
        ),
      ],
    ),
  );
}

Future createDir(String dirName) async {
  final appDir = await getApplicationDocumentsDirectory();
  final myDir = Directory('${appDir.path}/$dirName');

  // 查看目录是否存在
  bool isExist = await myDir.exists();
  if (!isExist) {
    myDir.create(recursive: true);
  }
  return myDir.path;
}

Future<void> saveImage(String dirName, String fileName, ByteData image) async {
  final appDir = await getApplicationDocumentsDirectory();
  final myDir = Directory('${appDir.path}/$dirName');

  // 查看目录是否存在
  bool isExist = await myDir.exists();
  if (!isExist) {
    myDir.create(recursive: true);
  }

  // final myDir = await Directory('${appDir.path}/$dirName').create(recursive: true);
  final localPath = mypath.join(myDir.path, fileName);
  print('localPath = $localPath');
  // localPath = /data/user/0/com.example.hyzp_yibin_bmfmap/app_flutter/myIcons/myIcon1.png
  File(localPath).writeAsBytesSync(image.buffer.asInt8List());
}

Future<ByteData> widgetToImage(Widget widget,
    {Alignment alignment = Alignment.center,
    Size size = const Size(double.maxFinite, double.maxFinite),
    double devicePixelRatio = 1.0,
    double pixelRatio = 1.0}) async {
  RenderRepaintBoundary repaintBoundary = RenderRepaintBoundary();

  RenderView renderView = RenderView(
    child: RenderPositionedBox(alignment: alignment, child: repaintBoundary),
    configuration: ViewConfiguration(
      size: size,
      devicePixelRatio: devicePixelRatio,
    ),
    window: ui.window,
  );

  PipelineOwner pipelineOwner = PipelineOwner();
  pipelineOwner.rootNode = renderView;
  renderView.prepareInitialFrame();

  BuildOwner buildOwner = BuildOwner();
  buildOwner.focusManager = FocusManager();
  RenderObjectToWidgetElement rootElement = RenderObjectToWidgetAdapter(
    container: repaintBoundary,
    child: widget,
  ).attachToRenderTree(buildOwner);
  buildOwner.buildScope(rootElement);
  buildOwner.finalizeTree();

  pipelineOwner.flushLayout();
  pipelineOwner.flushCompositingBits();
  pipelineOwner.flushPaint();

  ui.Image image = await repaintBoundary.toImage(pixelRatio: pixelRatio);
  // E/flutter (10823): [ERROR:flutter/flow/layers/transform_layer.cc(24)] TransformLayer is constructed with an invalid matrix.
  // E/flutter (10823): [ERROR:flutter/flow/layers/transform_layer.cc(24)] TransformLayer is constructed with an invalid matrix.
  ByteData byteData = await image.toByteData(format: ui.ImageByteFormat.png);

  return byteData;
}

// read image file from path
Future<File> getLocalFile(String filename) async {
  String dir = (await getApplicationDocumentsDirectory()).path;
  final directoryName = "myIcons";
  File file = new File('$dir/$directoryName/$filename');
  return file;
}