javafx-8 - JavaFX 加载 FXML 的性能问题

Question

我有一个带有切换按钮的主文件，单击其中一个按钮后，我将启动一个新的 FXMLLoader，其中包含大约 10 个 SVG、15 个文本字段和 6 个微调器。此外，它还具有 CSS 来相应地渲染节点...它可以正常加载，没有错误或任何问题，但在显示场景之前需要一两秒。

我猜这是由于同时初始化的节点数量所致。有没有办法在节点开始初始化之前显示场景？

注意:我的项目要求我在点击时导航到不同的场景。

从选择它的地方切换按钮

   if(settings.isSelected()){
        Stage stage = (Stage) mainWrapper.getScene().getWindow();
        Parent root = FXMLLoader.load(getClass().getResource("/fxmlFiles/settings.fxml"));
        stage.setScene(new Scene(root, Screen.getPrimary().getVisualBounds().getWidth(),
                Screen.getPrimary().getVisualBounds().getHeight()));
        stage.centerOnScreen();
        //stage.setMaximized(true);
        stage.show();
    }

fxml文件

    <FlowPane xmlns:fx="http://javafx.com/fxml"
    fx:controller="controllers.motelInfoController"
    stylesheets="/cssFiles/motelInfo.css"
    fx:id="content">

    <VBox fx:id="mainWrapper">
    <VBox fx:id="validationWrapper">
        <Label fx:id="validationLabel" visible="false"/>
    </VBox>
    <VBox fx:id="generalInfo">
    <HBox> <!--First Row-->
            <HBox>
            <Group>
                <SVGPath fx:id="iconMotelName" scaleX="0.05" scaleY="0.05" fill="white"/>
            </Group>
            <Group>
                <TextField fx:id="miName" promptText="Motel Name"/>
            </Group>
            </HBox>
            <HBox>
                <Group>
                    <TextField fx:id="miFranchiseName" promptText="Franchise Name"/>
                </Group>
            </HBox>
        </HBox>
    <HBox> <!--Second Row-->
            <HBox>
                <Group>
                    <SVGPath fx:id="iconMotelAddress" scaleX="0.05" scaleY="0.05" fill="white"/>
                </Group>
                <Group>
                    <TextField fx:id="miAddress" promptText="Street Name"/>
                </Group>
            </HBox>
            <HBox>
                <Group>
                <TextField fx:id="miCity" promptText="City/Town Name"/>
                </Group>
            </HBox>
        </HBox>
    <HBox><!--Third Row-->
            <HBox style="-fx-spacing: 25px;">
                <Label></Label> <!--Empty label for purpose of leaving icon gap since N/A here-->
                <Group>
                    <TextField fx:id="miState" promptText="State"/>
                </Group>
            </HBox>
            <HBox>
                <Group>
                    <TextField fx:id="miZipCode" promptText="Zip Code"/>
                </Group>
            </HBox>
            <HBox>
                <Group>
                    <SVGPath fx:id="iconMotelContact" scaleX="0.05" scaleY="0.05" fill="white"/>
                </Group>
                <Group>
                    <TextField fx:id="miContact" promptText="Contact no."/>
                </Group>
            </HBox>
        </HBox>
    <HBox> <!--Fourth Row-->
            <HBox>
                <Group>
                    <SVGPath fx:id="iconMotelFax" scaleX="0.05" scaleY="0.05" fill="white"/>
                </Group>
                <Group>
                    <TextField fx:id="miFax" promptText="Fax no."/>
                </Group>
            </HBox>
            <HBox>
                <Group>
                    <SVGPath fx:id="iconMotelEmail" scaleX="0.05" scaleY="0.05" fill="white"/>
                </Group>
                <Group>
                    <TextField fx:id="miEmail" promptText="Email id"/>
                </Group>
            </HBox>
            <HBox>
                <Group>
                    <SVGPath fx:id="iconMotelNoOfRooms" scaleX="0.05" scaleY="0.05" fill="white"/>
                </Group>
                <Group>
                    <TextField fx:id="miNOR" promptText="No. of Rooms"/>
                </Group>
            </HBox>
        </HBox>
    <HBox style="-fx-spacing: 50px"> <!--Fifth Row-->
            <HBox>
                <Group>
                    <SVGPath fx:id="iconMotelCheckInTime" scaleX="0.05" scaleY="0.05" fill="white"/>
                </Group>
                <Group>
                    <Spinner fx:id="hourSpinnerCIT"/>
                </Group>
                <Group>
                    <Spinner fx:id="minSpinnerCIT"/>
                </Group>
                <Group>
                    <Spinner fx:id="secSpinnerCIT"/>
                </Group>
            </HBox>
            <HBox>
                <Group>
                    <SVGPath fx:id="iconMotelCheckOutTime" scaleX="0.05" scaleY="0.05" fill="white"/>
                </Group>
                <Group>
                    <Spinner fx:id="hourSpinnerCOT"/>
                </Group>
                <Group>
                    <Spinner fx:id="minSpinnerCOT"/>
                </Group>
                <Group>
                    <Spinner fx:id="secSpinnerCOT"/>
                </Group>
            </HBox>
        </HBox>
    </VBox>
    <VBox fx:id="roomOccupancy">
    <HBox> <!--First Row-->
            <Label fx:id="labelMaxGuestSelection"
                   text="Maximum Allowed Guest in individual Rooms. Please state the max count in adjacent cells"/>
            <VBox>
                <HBox>
                    <Group>
                        <SVGPath fx:id="iconMotelSingleBed" scaleX="0.05" scaleY="0.05" fill="white"/>
                    </Group>
                    <Group>
                        <TextField fx:id="miSB" promptText="Single Bed"/>
                    </Group>
                </HBox>
                <HBox>
                    <Group>
                        <SVGPath fx:id="iconMotelTwoBeds" scaleX="0.05" scaleY="0.05" fill="white"/>
                    </Group>
                    <Group>
                        <TextField fx:id="miTB" promptText="Two Beds"/>
                    </Group>
                </HBox>
                <HBox>
                    <Group>
                        <SVGPath fx:id="iconMotelfamilyRoom" scaleX="0.05" scaleY="0.05" fill="white"/>
                    </Group>
                    <Group>
                        <TextField fx:id="miFR" promptText="Family Room"/>
                    </Group>
                </HBox>
            </VBox>
        </HBox>
    <HBox> <!--Second Row-->
            <Label fx:id="labelMaxGuestCharged"
                    text="Rate Charged per Guest after max. allowed guest exceeds in a room"/>
            <HBox>
                <Group>
                    <SVGPath fx:id="iconMotelGuestExceedRate" scaleX="0.05" scaleY="0.05" fill="white"/>
                </Group>
                <Group>
                    <TextField fx:id="miGER" promptText="Rate/Guest Exceeded"/>
                </Group>
            </HBox>
        </HBox>
    </VBox>
    <VBox fx:id="submissionWrapper">
    <Group>
    <Button fx:id="submit" text="UPDATE" onAction="#saveData"/>
    </Group>
    </VBox>
    </VBox>

    </FlowPane>

FXML Controller

@Override
public void initialize(URL location, ResourceBundle resources) {

    //Load the data if the motelInfo file exist
    File checkTemp = new File("motelDetails.ser");
    if(checkTemp.exists()){
        readDataFromFile();
    }

    //Getting Values for the spinner
    for(int i=0;i<24;i++){
        hourList.add(String.format("%02d", i));
    }
    final SpinnerValueFactory<String> hourValuesCIT = new SpinnerValueFactory.ListSpinnerValueFactory<>(hourList);
    final SpinnerValueFactory<String> hourValuesCOT = new SpinnerValueFactory.ListSpinnerValueFactory<>(hourList);
    for(int i=0; i<60; i++){
        minList.add(String.format("%02d", i));
        secList.add(String.format("%02d", i));
    }
    final SpinnerValueFactory<String> minValuesCIT = new SpinnerValueFactory.ListSpinnerValueFactory<>(minList);
    final SpinnerValueFactory<String> minValuesCOT = new SpinnerValueFactory.ListSpinnerValueFactory<>(minList);
    final SpinnerValueFactory<String> secValuesCIT = new SpinnerValueFactory.ListSpinnerValueFactory<>(secList);
    final SpinnerValueFactory<String> secValuesCOT = new SpinnerValueFactory.ListSpinnerValueFactory<>(secList);

    styleSpinner(hourSpinnerCIT, hourValuesCIT);
    styleSpinner(hourSpinnerCOT, hourValuesCOT);
    styleSpinner(minSpinnerCIT, minValuesCIT);
    styleSpinner(minSpinnerCOT, minValuesCOT);
    styleSpinner(secSpinnerCIT, secValuesCIT);
    styleSpinner(secSpinnerCOT, secValuesCOT);


} 

Answer 1

看来你有两个问题:

1. 在阻止更新的 UI 线程上运行长时间操作 (readDataFromFile())
2. 在 FXMLLoader.load() 中完成这一切，在完成之前不允许绘制任何东西

我建议通过在不同的线程中运行加载并在加载时显示加载屏幕来解决这两个问题。看下一个例子:

public class Main extends Application {

    @Override
    public void start(Stage stage) throws Exception {
        StackPane loadingRoot = new StackPane();

        loadingRoot.getChildren().setAll(new ProgressIndicator());
        final Scene scene = new Scene(loadingRoot);

        stage.setWidth(400);
        stage.setHeight(400);
        stage.setScene(scene);
        stage.show();

        new Thread(() -> {
            veryLongOperation();

            // we need to wrap UI code in Platform
            Platform.runLater(() -> {
                Parent root;
                try {
                    root = FXMLLoader.load(Main.class.getResource("FXMLDocument.fxml"));
                    scene.setRoot(root);
                } catch (IOException ex) {
                }
            });
        }).start();
    }

    public static void veryLongOperation() {
            try {
                // long-long operation
                Thread.sleep(5000);
            } catch (Exception ex) {
            }

    }
}