javafx.fxml.LoadException: Root hasn't been set. Use method setRoot() before load.
阿新 • • 發佈:2018-11-27
一、問題描述:
二、程式碼:
<!-- PersonOverview.fxml --> <?xml version="1.0" encoding="UTF-8"?> <?import java.lang.*?> <?import javafx.scene.control.*?> <?import javafx.scene.layout.*?> <?import javafx.scene.control.Button?> <?import javafx.scene.control.Label?> <?import javafx.scene.control.SplitPane?> <?import javafx.scene.control.TableColumn?> <?import javafx.scene.control.TableView?> <?import javafx.scene.layout.AnchorPane?> <?import javafx.scene.layout.ColumnConstraints?> <?import javafx.scene.layout.GridPane?> <?import javafx.scene.layout.HBox?> <?import javafx.scene.layout.RowConstraints?> <!--告訴 PersonOverview.fxml使用的是哪個控制器以及元素與控制器中的屬性的對應關係.fx:controller="ch.makery.address.view.PersonOverviewController"--> <fx:root prefHeight="400.0" prefWidth="600.0" type="AnchorPane" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="ch.makery.address.view.PersonOverviewController"> <children> <SplitPane dividerPositions="0.29797979797979796" layoutX="44.0" layoutY="14.0" prefHeight="400.0" prefWidth="600.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0"> <items> <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="160.0" prefWidth="100.0"> <children> <TableView fx:id="personTable" layoutX="-12.0" prefHeight="200.0" prefWidth="200.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0"> <columns> <TableColumn fx:id="firstNameColumn" prefWidth="75.0" text="FirstName" /> <TableColumn fx:id="lastNameColumn" prefWidth="75.0" text="LastName" /> </columns> <columnResizePolicy> <TableView fx:constant="CONSTRAINED_RESIZE_POLICY" /> </columnResizePolicy> </TableView> </children> </AnchorPane> <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="160.0" prefWidth="100.0"> <children> <Label layoutX="14.0" layoutY="7.0" text="Person Details" AnchorPane.leftAnchor="5.0" AnchorPane.topAnchor="5.0" /> <GridPane layoutX="46.0" layoutY="109.0" AnchorPane.leftAnchor="5.0" AnchorPane.rightAnchor="5.0" AnchorPane.topAnchor="30.0"> <columnConstraints> <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" /> <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" /> </columnConstraints> <rowConstraints> <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /> </rowConstraints> <children> <Label fx:id="firstNameLabel" text="First Name" /> <Label text="Label" GridPane.columnIndex="1" /> <Label fx:id="lastNameLabel" text="Last Name" GridPane.rowIndex="1" /> <Label text="Label" GridPane.columnIndex="1" GridPane.rowIndex="1" /> <Label fx:id="streetLabel" text="Street" GridPane.rowIndex="2" /> <Label text="Label" GridPane.columnIndex="1" GridPane.rowIndex="2" /> <Label fx:id="cityLabel" text="City" GridPane.rowIndex="3" /> <Label text="Label" GridPane.columnIndex="1" GridPane.rowIndex="3" /> <Label fx:id="postalCodeLabel" text="Postal code" GridPane.rowIndex="4" /> <Label text="Label" GridPane.columnIndex="1" GridPane.rowIndex="4" /> <Label fx:id="birthdayLabel" text="Birthday" GridPane.rowIndex="5" /> <Label text="Label" GridPane.columnIndex="1" GridPane.rowIndex="5" /> </children> </GridPane> <HBox layoutX="209.0" layoutY="328.0" spacing="8.0"> <children> <Button mnemonicParsing="false" text="New" /> <Button mnemonicParsing="false" text="Edit" /> <Button mnemonicParsing="false" text="Delete" /> </children> </HBox> </children> </AnchorPane> </items> </SplitPane> </children> </fx:root>
// mainApp package ch.makery.address; // 這裡的 Stage 是一個主容器,它就是我們通常所認為的視窗(有邊,高和寬,還有關閉按鈕)。 // 在這個 Stage 裡面,你可以放置一個 Scene,當然你可以切換別的 Scene,而在這個 Scene 裡面,我們就可以放置各種各樣的控制元件 import java.io.IOException; import ch.makery.address.model.Person; import ch.makery.address.view.PersonOverviewController; import javafx.application.Application; import javafx.collections.FXCollections; import javafx.collections.ObservableList; import javafx.fxml.FXMLLoader; import javafx.scene.Scene; import javafx.scene.layout.AnchorPane; import javafx.scene.layout.BorderPane; import javafx.stage.Stage; public class mainApp extends Application { private Stage primaryStage; private BorderPane rootLayout; /** * The data as an observable list of Persons. */ /** * The data as an observable list of Persons. */ private ObservableList<Person> personData = FXCollections.observableArrayList(); /** * Constructor */ public mainApp() { // Add some sample data personData.add(new Person("Hans", "Muster")); personData.add(new Person("Ruth", "Mueller")); personData.add(new Person("Heinz", "Kurz")); personData.add(new Person("Cornelia", "Meier")); personData.add(new Person("Werner", "Meyer")); personData.add(new Person("Lydia", "Kunz")); personData.add(new Person("Anna", "Best")); personData.add(new Person("Stefan", "Meier")); personData.add(new Person("Martin", "Mueller")); } /** * Returns the data as an observable list of Persons. * @return */ public ObservableList<Person> getPersonData() { return personData; } @Override public void start(Stage primaryStage) { this.primaryStage = primaryStage; this.primaryStage.setTitle("AddressApp"); initRootLayout(); showPersonOverview(); } /** * Initializes the root layout. */ public void initRootLayout() { try { // Load root layout from fxml file. FXMLLoader loader = new FXMLLoader(); loader.setLocation(mainApp.class.getResource("view/RootLayout.fxml")); rootLayout = (BorderPane) loader.load(); // Show the scene containing the root layout. Scene scene = new Scene(rootLayout); primaryStage.setScene(scene); primaryStage.show(); } catch (IOException e) { e.printStackTrace(); } } /** * Shows the person overview inside the root layout. */ public void showPersonOverview() { try { // Load person overview. FXMLLoader loader = new FXMLLoader(); loader.setLocation(mainApp.class.getResource("view/PersonOverview.fxml")); AnchorPane personOverview = (AnchorPane) loader.load(); // Set person overview into the center of root layout. rootLayout.setCenter(personOverview); // Give the controller access to the main app. PersonOverviewController controller = loader.getController(); controller.setMainApp(this); } catch (IOException e) { e.printStackTrace(); } } /** * Returns the main stage. * @return */ public Stage getPrimaryStage() { return primaryStage; } public static void main(String[] args) { launch(args); } }
三、原因:(截圖來自 https://stackoverflow.com/questions/23729277/javafx-fxml-load-file-issues-with-setting-root)
四、解決:用 Scene Builder 開啟 PersonOverview.fxml(根據你自己的檔名),找到Document下的Controller組(一般在左下角),取消對的選擇
儲存,然後回到 IDEA中,執行mainApp,就可以正常執行啦!下面是修改過後的PersonOverview.fxml中的程式碼(注意:在Scene Builder中修改並儲存,那麼它的程式碼也是會自動修改的)
<?xml version="1.0" encoding="UTF-8"?>
<?import java.lang.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.SplitPane?>
<?import javafx.scene.control.TableColumn?>
<?import javafx.scene.control.TableView?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.RowConstraints?>
<!--告訴 PersonOverview.fxml使用的是哪個控制器以及元素與控制器中的屬性的對應關係.fx:controller="ch.makery.address.view.PersonOverviewController"-->
<AnchorPane prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="ch.makery.address.view.PersonOverviewController">
<children>
<SplitPane dividerPositions="0.29797979797979796" layoutX="44.0" layoutY="14.0" prefHeight="400.0" prefWidth="600.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<items>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="160.0" prefWidth="100.0">
<children>
<TableView fx:id="personTable" layoutX="-12.0" prefHeight="200.0" prefWidth="200.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<columns>
<TableColumn fx:id="firstNameColumn" prefWidth="75.0" text="FirstName" />
<TableColumn fx:id="lastNameColumn" prefWidth="75.0" text="LastName" />
</columns>
<columnResizePolicy>
<TableView fx:constant="CONSTRAINED_RESIZE_POLICY" />
</columnResizePolicy>
</TableView>
</children>
</AnchorPane>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="160.0" prefWidth="100.0">
<children>
<Label layoutX="14.0" layoutY="7.0" text="Person Details" AnchorPane.leftAnchor="5.0" AnchorPane.topAnchor="5.0" />
<GridPane layoutX="46.0" layoutY="109.0" AnchorPane.leftAnchor="5.0" AnchorPane.rightAnchor="5.0" AnchorPane.topAnchor="30.0">
<columnConstraints>
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
</columnConstraints>
<rowConstraints>
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
</rowConstraints>
<children>
<Label fx:id="firstNameLabel" text="First Name" />
<Label text="Label" GridPane.columnIndex="1" />
<Label fx:id="lastNameLabel" text="Last Name" GridPane.rowIndex="1" />
<Label text="Label" GridPane.columnIndex="1" GridPane.rowIndex="1" />
<Label fx:id="streetLabel" text="Street" GridPane.rowIndex="2" />
<Label text="Label" GridPane.columnIndex="1" GridPane.rowIndex="2" />
<Label fx:id="cityLabel" text="City" GridPane.rowIndex="3" />
<Label text="Label" GridPane.columnIndex="1" GridPane.rowIndex="3" />
<Label fx:id="postalCodeLabel" text="Postal code" GridPane.rowIndex="4" />
<Label text="Label" GridPane.columnIndex="1" GridPane.rowIndex="4" />
<Label fx:id="birthdayLabel" text="Birthday" GridPane.rowIndex="5" />
<Label text="Label" GridPane.columnIndex="1" GridPane.rowIndex="5" />
</children>
</GridPane>
<HBox layoutX="209.0" layoutY="328.0" spacing="8.0">
<children>
<Button mnemonicParsing="false" text="New" />
<Button mnemonicParsing="false" text="Edit" />
<Button mnemonicParsing="false" text="Delete" />
</children>
</HBox>
</children>
</AnchorPane>
</items>
</SplitPane>
</children>
</AnchorPane>