我正在学习JavaFX，并且一直坚持绘制图表。 任务如下：我有四个选项卡的TabPane，每个选项卡中都有LineChart。 当我以第一张图表结束时，我发现IDE显示无法使用为第一张图表创建的xAxis和yAxis。我真的需要为每个LineChart创建不同的NumberAxis吗？

代码：

public class Controller implements Initializable {
    @FXML
    private NumberAxis xAxis = new NumberAxis();
    @FXML
    private NumberAxis yAxis = new NumberAxis();
    @FXML
    private LineChart<Number,Number> exactChart,eulerChart,eulerImpchart,rungeKuttaChart; 

    @Override
     public void initialize(URL url,ResourceBundle resourceBundle) {
        xAxis.setLowerBound(x0);
        xAxis.setUpperBound(X);
        xAxis.setTickUnit(xScale);

        yAxis.setLowerBound(-2);
        yAxis.setUpperBound(2);
        yAxis.setTickUnit(yScale);
        plotExact();
   }
   //More code 
}

FXML文件：

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.chart.*?>
<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<TabPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="720.0" prefWidth="1024.0" tabClosingPolicy="UNAVAILABLE" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.SecondStage">
  <tabs>
    <Tab text="Exact">
      <content>
        <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="200.0">
               <children>
                  <LineChart fx:id="exactChart" layoutY="7.0" prefHeight="676.0" prefWidth="1024.0">
                    <xAxis>
                      <NumberAxis fx:id="xAxis" side="BOTTOM" autoRanging="false"/>
                    </xAxis>
                    <yAxis>
                      <NumberAxis fx:id="yAxis" side="LEFT" autoRanging="false" />
                    </yAxis>
                  </LineChart>
               </children></AnchorPane>
      </content>
    </Tab>
    <Tab text="Euler">
      <content>
        <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="200.0">
          <children>
            <LineChart fx:id="eulerChart" layoutY="7.0" prefHeight="676.0" prefWidth="1024.0">
              <xAxis>
                <NumberAxis fx:id="xAxis" side="BOTTOM" autoRanging="false" />
              </xAxis>
              <yAxis>
                <NumberAxis fx:id="yAxis" side="LEFT" autoRanging="false" />
              </yAxis>
            </LineChart>
          </children></AnchorPane>
      </content>
    </Tab>
  </tabs>
</TabPane>