Flutter CustomPainter Canvas 图片质量模糊的问题

In Flutter, how to associate device pixel ratio with a canvas created from scratch?

    final MyCustomPainter p = MyCustomPainter(_counter);
    ui.PictureRecorder recorder = ui.PictureRecorder();
    Canvas canvas = Canvas(recorder);
    canvas.save();
    canvas.scale(ui.window.devicePixelRatio);
    //其他绘制在这里开始

    p.paint(canvas, const Size(SIZE, SIZE));
    canvas.restore();
    final imageSize = (SIZE * ui.window.devicePixelRatio).floor();
    recorder.endRecording().toImage(imageSize, imageSize).then((image) {
      image.toByteData(format: ui.ImageByteFormat.png).then((ByteData? data) {
        if (data != null) {
          _image = data.buffer.asUint8List();
          setState(() {});
        }
      });
    });

也就是说一定要先用

canvas.save();
canvas.scale(ui.window.devicePixelRatio);