flutter截取当前widget并分享

RepaintBoundary(
      key: repaintWidgetKey,
      child: Container(
        width: _boxWidth + Adapter.px(30),
        height:_boxHeight + Adapter.px(isPhone ? 30 : 44),
        padding: EdgeInsets.only(top: Adapter.px(10), bottom: Adapter.px(isPhone ? 20 : 34), left: Adapter.px(15), right: Adapter.px(15)),
        color: Color(0xFFD3F4FD),
        child:  Container(
            width: _boxWidth,
            height: _boxHeight,
            decoration: BoxDecoration(
              color: Colors.white,
              boxShadow: [
                BoxShadow(
                  offset: Offset(0, Adapter.px(2)),
                  blurRadius: Adapter.px(14),
                  color: Color(0x29000000),
                  spreadRadius: 0,
                )
              ],
              borderRadius: BorderRadius.circular(_borderRadius),
            ),
            child: Stack(
              children: <Widget>[
                _renderRecord(),
                _renderDivider(),
                _renderDownTip(),
                _renderQRCode(),
              ],
            )),
      ),
    )

GlobalKey repaintWidgetKey = GlobalKey(); // 绘图key值

import 'dart:ui' as ui;
import 'dart:async';

  /// 截屏图片生成图片流ByteData
Future<ByteData> _capturePngToByteData() async {
    try {
      RenderRepaintBoundary boundary = repaintWidgetKey.currentContext
          .findRenderObject();
      double dpr = ui.window.devicePixelRatio; // 获取当前设备的像素比
      ui.Image image = await boundary.toImage(pixelRatio: dpr);
      ByteData _byteData = await image.toByteData(format: ui.ImageByteFormat.png);
      return _byteData;
    } catch (e) {
      print(e);
    }
    return null;
  }

void saveImage() async {
    // 截屏
    ByteData byteData = await QSCommon.capturePngToByteData(key);

    Uint8List pngBytes = byteData.buffer.asUint8List();
    print(pngBytes);

    final result = await ImageGallerySaver.saveImage(
      Uint8List.fromList(pngBytes),
      quality: 100,
    );

    Fluttertoast.showToast(msg: "保存成功");
    print(result);
  }

void shareVxImage() async {
    ByteData byteData = await QSCommon.capturePngToByteData(key);

    Uint8List pngBytes = byteData.buffer.asUint8List();
    Directory tempDir = await getTemporaryDirectory();

    String storagePath = tempDir.path;
    File file = new File('$storagePath/enarate.png');
    if (!file.existsSync()) {
      file.createSync();
    }
    file.writeAsBytesSync(pngBytes);

    print(file);

    WxSdk.ShareImage(
      //分享图片

      file: "/data/user/0/com.xinxing.cixi_community/cache/enarate.png",
    );
  }