相关疑难解决方法(0)

为了在谷歌地图google_maps_flutter上显示自定义小部件，我使用了一个非常方便的函数，可以将任何Widget（包括包含图像的）转换为Image，然后将其转换为Uint8List我需要的。它在 iOS 和 Android 上运行良好。

Future createImageFromWidget( Widget widget){
  final RenderRepaintBoundary repaintBoundary = RenderRepaintBoundary();
  final RenderView renderView = RenderView(
    child: RenderPositionedBox(alignment: Alignment.center, child: repaintBoundary),
    configuration: ViewConfiguration(size: const Size.square(300.0), devicePixelRatio: ui.window.devicePixelRatio),
    window: null,
  );

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

  final BuildOwner buildOwner = BuildOwner(focusManager: FocusManager());
  final RenderObjectToWidgetElement<RenderBox> rootElement = RenderObjectToWidgetAdapter<RenderBox>(
    container: repaintBoundary,
    child: Directionality(
      textDirection: TextDirection.ltr,
      child: IntrinsicHeight(child: IntrinsicWidth(child: widget)),
    ),
  ).attachToRenderTree(buildOwner);

  buildOwner..buildScope(rootElement)..finalizeTree();
  pipelineOwner..flushLayout()..flushCompositingBits()..flushPaint();

  return repaintBoundary.toImage(pixelRatio: ui.window.devicePixelRatio)
    .then((image) => image.toByteData(format: …