更改javafx中fxml標簽的文本時出現空點異常

Question

公共類SerialCommunicationController {

    @FXML public Label tempReading;
    @FXML public Label errorReading;

    private final Logger logger = LoggerFactory.getLogger(getClass());
    private ArduinoInterfaceControl arduinoInterfaceControl;
    private Stage stage;
    private String prop;
    private String inte;
    private String deri;
    private boolean lastCommandSuccessful;
    public static final String LOCAL_SIMULATOR = "Local Simulator";
    private String[] params;
    private ArduinoInterfaceControl arduinoInterface;
    public SerialCommunicationController() {
    }
    public SerialCommunicationController(String cmd){
        setValues(cmd);
    }

    public void setValues(String readings){
        String[] params = readings.split("\\s+");
        // something went wrong, just decode to blank.
        if(params.length < 1) {
            lastCommandSuccessful = false;
        }
        else {
            tempReading.setText(params[0]);
            errorReading.setText(params[1]);
            // successful command received.
            lastCommandSuccessful = Boolean.valueOf(params[1]);
        }
    }

}

嗨，大家好，我在嘗試執行tempReading.setText()和errorReading.setText()時遇到了NullPointException errorReading.setText() 。 我在fxml文件中定義了標簽文本的默認值。

Answer 1

看來tempReading和errorReading都為null。 也許綁定到FXML是不正確的？

確保FXML文件中的fx:id與Java類中Label字段的名稱匹配。