相关疑难解决方法(0)

下面的代码列出了一个图表,我需要在图表中实现图表在垂直(高度)和水平(宽度)方向上的扩展.建议的方法(例如https://docs.flutter.io/flutter/widgets/Row-class.html)将Expanded在Row或中使用Column.

我正在尝试扩展的图表小部件扩展CustomPaint,没有孩子,所有内容都是使用CustomPainter画布绘制的CustomPainter.paint(canvas, size).

这段代码

return new Scaffold(
  appBar: new AppBar(
    title: new Text(widget.title),
  ),
  body: new Center(    
    child: new Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        new Text(
          'vvvvvvvv:',
        ),
        new RaisedButton(
          color: Colors.green,
          onPressed: _chartStateChanger,
        ),
        new Text(
          'vvvvvvvv:',
        ),    
        new Expanded( // Expanded in Column, no expansion vertically 
          child: new Row(
            children: [
              new Text('>>>'),    
              new Expanded(// Expanded in Row, expands horizontally
                child: new Chart(  // …