Cannot read property 'scales' of undefined

該報錯在 antv f2 繪制柱狀圖文本是產生
原因： 在圖表渲染之前繪制
解決：在 chart.render(); 之后繪制

// ....

   chart.render();

      // 繪制柱狀圖文本
      const offset = -5;
      const canvas = chart.get("canvas");
      const group = canvas.addGroup();
      const shapes = {};
      data.forEach(function(obj) {
        const point = chart.getPosition(obj);
        const text = group.addShape("text", {
          attrs: {
            x: point.x,
            y: point.y + offset,
            text: obj.confirmedCount,
            textAlign: "center",
            textBaseline: "bottom",
            fill: "#808080"
          }
        });
        shapes[obj.year] = text; // 緩存該 shape, 便於后續查找
      });