JAVA 引用对象形式 class A in other class

Question

我有一个 class:

public class RectangularSection {

public double widthRectangle;

public double getWidthRectangle() {
    return widthRectangle;
}

public void setWidthRectangle(double widthRectangle) {
    this.widthRectangle = widthRectangle;
}}

和 class 对象 "section":

public class RectangleController implements Initializable {

RectangularSection section = new RectangularSection();

public RectangularSection getObject(){
    return section;
}

public void setRectangularSection(RectangularSection obj){
    this.section = obj;
}

@FXML
private TextField widthRectangle;

public TextField getWidthRectangle() {
    return widthRectangle;
}

public void setWidthRectangle(TextField widthRectangle) {
    this.widthRectangle = widthRectangle;
}

@Override
public void initialize(URL arg0, ResourceBundle arg1) {
}}

我需要来自 RectangleController 的对象 "section" class

public class Controller implements Initializable  {

RectangularSection section = new RectangularSection();
RectangleController object2 = new RectangleController();

@FXML
private Label szer;

    @FXML
private void sendStrengthClassOfConcrete() {
    object2.setRectangularSection(section);
    object2.section.setWidthRectangle(Double.parseDouble(object2.getWidthRectangle().getText()));
    szerokosc.setText(String.valueOf(object2.getObjekt().getWidthRectangle()));


}}

我读到了这个，我也做了同样的事情，但它不起作用我做错了什么？ ..................................................... .....................

Answer 1

代码改进的范围很大，但我不会完全重构代码。

对于您的缺陷，您没有设置 widthRectangle 字段，而是试图通过 .getWidthRectangle().getText() 获取它，这会抛出 NullPointerException

要解决它，请在 sendStrengthClassOfConcrete() 方法中使用它之前设置 widthRectangle 值。

private void sendStrengthClassOfConcrete() {
        object2.setRectangularSection(section);
        TextField someNumberTextField = new TextField("24");
        object2.setWidthRectangle(someNumberTextField);
        object2.section.setWidthRectangle(Double.parseDouble(object2
                .getWidthRectangle().getText()));

JAVA 引用对象形式 class A in other class

JAVA Reference to object form class A in other class

java

javafx

fxml