JavaFX8-选项卡窗格和选项卡，每个选项卡具有单独的FXML和控制器

我希望得到一些关于使用fx的答案：在tabpane中包含每个选项卡的语句。我已经很容易地让内容显示出来，但引用关联控制器类的方法只会给我一个nullpointerreference异常，不管我如何构造它。包含的FXML布局的控制器既没有构造函数也没有initialize（）方法，是否需要它们？我尝试了一些不同的东西，但总是得到相同的例外

我所做的只是在tabpane中添加一个更改侦听器，当按下一个选项卡时，我想用从全局可访问的arraylist获得的一些值填充一些文本字段。注意：arraylist不是问题所在，使用主控制器执行此操作可以正常工作

我将很快添加一个代码示例，但现在无法添加。如果您需要更多信息，请告诉我，否则我将在今天晚些时候发布代码

*编辑，这是我的代码示例，取自StackOverflow上的另一个线程。

TestApp.java：

public class TestApp extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {
        Scene scene = new Scene(new StackPane());

        FXMLLoader loader = new FXMLLoader(getClass().getResource("/view/MainTestWindow.fxml"));
        scene.setRoot(loader.load());
        MainTestController controller = loader.getController();
        controller.init();

        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

主控制器，其中我要引用子控制器

public class MainTestController {

    @FXML private TabPane tabPane;
    // Inject tab content.
    @FXML private Tab fooTabPage;
    // Inject controller
    @FXML private FooTabController fooTabPageController;

    // Inject tab content.
    @FXML private Tab barTabPage;
    // Inject controller
    @FXML private BarTabController barTabPageController;

    public void init() {
        tabPane.getSelectionModel().selectedItemProperty().addListener((ObservableValue<? extends Tab> observable,
                                                                        Tab oldValue, Tab newValue) -> {
            if (newValue == barTabPage) {
                System.out.println("Bar Tab page");
                barTabPageController.handleButton();
            } else if (newValue == fooTabPage) {
                System.out.println("Foo Tab page");
                fooTabPageController.handleButton();
            }
        });
    }
}

FooTab的.fxml：

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

<?import javafx.scene.layout.VBox?>
<?import javafx.scene.control.Label?>

<?import javafx.scene.control.Button?>
<VBox xmlns:fx="http://www.w3.org/2001/XInclude" fx:controller="controller.FooTabController">
    <Label fx:id="lblText" text="Helllo"/>
    <Button fx:id="btnFooTab" onAction="#handleButton" text="Change text"/>
</VBox>

BarTab's.fxml

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

<?import javafx.scene.layout.VBox?>
<?import javafx.scene.control.Label?>

<?import javafx.scene.control.Button?>
<VBox xmlns:fx="http://www.w3.org/2001/XInclude" fx:controller="controller.BarTabController">
    <Label fx:id="lblText" text="Helllo" />
    <Button fx:id="btnBarTab" onAction="#handleButton" text="Change text"/>
</VBox>

---

上述FooTab和BarTab的onAction都与各自的按钮一起工作。当此方法（handleButton）是来自主控制器的引用时，我会得到一个异常。

要为包含的FMXL文件插入控制器，您需要在

元素上添加

fx:id

属性。控制器将被注入到一个字段中，该字段的

fx:id

值后面附加了

“controller”

如果您还想插入实际的

选项卡

，则需要一个单独的

fx:id

因此：

及

---

结论：样本模板“注射分包商”
-上面的例子最终帮助我理解了注入机制。谢谢。
-我重新编写了代码，使其更加透明和清晰
-以下代码已完成并正在运行

tab1footcontroller.java

public class TabPaneRootController {

    @FXML private TabPane tabPane;

    //###################################Inject part#############################################
    // Inject tab content
    @FXML private Tab tab1_foo; //from TabPaneRootView.fxml: <Tab fx:id="tab1_foo" ...>
    @FXML private Tab tab2_bar; //from TabPaneRootView.fxml: <Tab fx:id="tab2_bar" ...>

    // Inject tab controller
    @FXML private Tab1fooController xxx_tab1foo_xxxController;//TabPaneRootView.fxml_include_fx:id="xxx_tab1foo_xxx" + "Controller"
    @FXML private Tab2barController xxx_tab2bar_xxxController;//TabPaneRootView.fxml_include_fx:id="xxx_tab2bar_xxx" + "Controller"
   //###########################################################################################

        public void init() {
               tabPane.getSelectionModel().selectedItemProperty().addListener((ObservableValue<? extends Tab> observable,
                                                                    Tab oldValue, Tab newValue) -> {                                                                                                    
            if (newValue == tab2_bar) {
                System.out.println("- 2.Tab bar -");
                System.out.println("xxx_tab2bar_xxxController=" + xxx_tab2bar_xxxController); //if =null => inject problem 
                xxx_tab2bar_xxxController.handleTab2ButtonBar();
            } else if (newValue == tab1_foo) {
                System.out.println("- 1.Tab foo -");
                System.out.println("xxx_tab1foo_xxxController=" + xxx_tab1foo_xxxController); //if =null => inject problem
                xxx_tab1foo_xxxController.handleTab1ButtonFoo();
            } else {
                System.out.println("- another Tab -");
            }
        });
    }
}

tab1fooView.fxml

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

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.VBox?>

<VBox xmlns="http://javafx.com/javafx/8.0.111" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controller.Tab1fooController">
    <Label fx:id="tab1_label_showText" text="Tab1_start" />
    <Button fx:id="tab1_button_foo" onAction="#handleTab1ButtonFoo" text="tab1_button_foo" />
</VBox>

tab2barView.fxml

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

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.VBox?>

<VBox xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.111" fx:controller="controller.Tab2barController">
    <Label fx:id="tab2_label_showText" text="Tab2_start" />
    <Button fx:id="tab2_button_bar" onAction="#handleTab2ButtonBar" text="tab2_button_bar" />
</VBox>

---

“引用关联控制器类的方法只会给我一个nullpointerreference异常，无论我如何构造它”。你能用你的问题来展示你尝试了什么吗？我现在已经用我目前拥有的测试代码更新了，请注意，非常感谢你，它立刻就起了作用！

@FXML private TabPane tabPane;
// Inject tab content.
@FXML private Tab fooTab;
// Inject controller
@FXML private FooTabController fooTabPageController;

// Inject tab content.
@FXML private Tab barTab;
// Inject controller
@FXML private BarTabController barTabPageController;

public class TabPaneRootController {

    @FXML private TabPane tabPane;

    //###################################Inject part#############################################
    // Inject tab content
    @FXML private Tab tab1_foo; //from TabPaneRootView.fxml: <Tab fx:id="tab1_foo" ...>
    @FXML private Tab tab2_bar; //from TabPaneRootView.fxml: <Tab fx:id="tab2_bar" ...>

    // Inject tab controller
    @FXML private Tab1fooController xxx_tab1foo_xxxController;//TabPaneRootView.fxml_include_fx:id="xxx_tab1foo_xxx" + "Controller"
    @FXML private Tab2barController xxx_tab2bar_xxxController;//TabPaneRootView.fxml_include_fx:id="xxx_tab2bar_xxx" + "Controller"
   //###########################################################################################

        public void init() {
               tabPane.getSelectionModel().selectedItemProperty().addListener((ObservableValue<? extends Tab> observable,
                                                                    Tab oldValue, Tab newValue) -> {                                                                                                    
            if (newValue == tab2_bar) {
                System.out.println("- 2.Tab bar -");
                System.out.println("xxx_tab2bar_xxxController=" + xxx_tab2bar_xxxController); //if =null => inject problem 
                xxx_tab2bar_xxxController.handleTab2ButtonBar();
            } else if (newValue == tab1_foo) {
                System.out.println("- 1.Tab foo -");
                System.out.println("xxx_tab1foo_xxxController=" + xxx_tab1foo_xxxController); //if =null => inject problem
                xxx_tab1foo_xxxController.handleTab1ButtonFoo();
            } else {
                System.out.println("- another Tab -");
            }
        });
    }
}

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

<?import javafx.scene.control.Tab?
<?import javafx.scene.control.TabPane?>

<TabPane fx:id="tabPane" xmlns="http://javafx.com/javafx/8.0.111" xmlns:fx="http://javafx.com/fxml/1"  fx:controller="controller.TabPaneRootController">
<tabs>
    <Tab fx:id="tab1_foo" text="myTab1foo">
        <fx:include fx:id="xxx_tab1foo_xxx" source="tab1fooView.fxml" />
    </Tab>
    <Tab fx:id="tab2_bar" text="myTab2bar">
        <fx:include fx:id="xxx_tab2bar_xxx" source="tab2barView.fxml" />
    </Tab>
</tabs>

public class Tab1fooController {
    @FXML private Label tab1_label_showText;

    public void handleTab1ButtonFoo() {
        if( tab1_label_showText.getText().equals("tab1 aaa") ) {
            tab1_label_showText.setText("tab1 iii");
        } else {
            tab1_label_showText.setText("tab1 aaa");
        }
    }
}

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

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.VBox?>

<VBox xmlns="http://javafx.com/javafx/8.0.111" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controller.Tab1fooController">
    <Label fx:id="tab1_label_showText" text="Tab1_start" />
    <Button fx:id="tab1_button_foo" onAction="#handleTab1ButtonFoo" text="tab1_button_foo" />
</VBox>

public class Tab2barController {
    @FXML private Label tab2_label_showText;

    public void handleTab2ButtonBar() {             
        if( tab2_label_showText.getText().equals("tab2 bbb") ) {
            tab2_label_showText.setText("tab2 jjj");
        } else {
            tab2_label_showText.setText("tab2 bbb");
        }
    }
}

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

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.VBox?>

<VBox xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.111" fx:controller="controller.Tab2barController">
    <Label fx:id="tab2_label_showText" text="Tab2_start" />
    <Button fx:id="tab2_button_bar" onAction="#handleTab2ButtonBar" text="tab2_button_bar" />
</VBox>

public class TestApp extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {
        Scene scene = new Scene(new StackPane());

        FXMLLoader loader = new FXMLLoader(getClass().getResource("/view/tabPaneRootView.fxml"));
        scene.setRoot(loader.load());
        TabPaneRootController controller = loader.getController();
        controller.init();

        primaryStage.setScene(scene);
        primaryStage.setTitle("Inject TabController");
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}