如何触发内部关闭请求？

Question

我在 JavaFX 中关闭 window 时遇到问题。

我根据需要定义 setOnCloseRequest，当我单击 window 中的 x 时它会起作用。但是，我还需要一个按钮来关闭 window 而这个 onCloseRequest 必须起作用，问题是它不起作用。该事件根本不会触发。

我正在使用 JavaFX 2.2 (Java 7)，我注意到 setOnCloseRequest 的参考资料说在 external 上关闭 window请求

Answer 1

解决方案

从您的内部关闭请求（在按下按钮时）触发一个事件，以便应用程序认为它收到了外部关闭请求。那么无论请求来自外部事件还是内部事件，您的关闭请求逻辑都可以相同。

private EventHandler<WindowEvent> confirmCloseEventHandler = event -> {
        // close event handling logic.
        // consume the event if you wish to cancel the close operation.
}

...

stage.setOnCloseRequest(confirmCloseEventHandler);

Button closeButton = new Button("Close Application");
closeButton.setOnAction(event ->
        stage.fireEvent(
                new WindowEvent(
                        stage,
                        WindowEvent.WINDOW_CLOSE_REQUEST
                )
        )
);

备注

这是一个Java 8+的解决方案，对于JavaFX 2，你将需要在匿名内部转换lambda函数类并且将无法使用Alert对话框，但需要提供您自己的警报对话框系统，因为 JavaFX 2 没有内置的系统。我强烈建议升级到 Java 8+ 而不是继续使用 JavaFX 2.

样本UI

示例代码

示例代码将向用户显示关闭确认警报，如果用户未确认关闭，则取消关闭请求。

import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.StackPane;
import javafx.stage.*;
import javafx.stage.WindowEvent;

import java.util.Optional;

public class CloseConfirm extends Application {

    private Stage mainStage;

    @Override
    public void start(Stage stage) throws Exception {
        this.mainStage = stage;
        stage.setOnCloseRequest(confirmCloseEventHandler);

        Button closeButton = new Button("Close Application");
        closeButton.setOnAction(event ->
                stage.fireEvent(
                        new WindowEvent(
                                stage,
                                WindowEvent.WINDOW_CLOSE_REQUEST
                        )
                )
        );

        StackPane layout = new StackPane(closeButton);
        layout.setPadding(new Insets(10));

        stage.setScene(new Scene(layout));
        stage.show();
    }

    private EventHandler<WindowEvent> confirmCloseEventHandler = event -> {
        Alert closeConfirmation = new Alert(
                Alert.AlertType.CONFIRMATION,
                "Are you sure you want to exit?"
        );
        Button exitButton = (Button) closeConfirmation.getDialogPane().lookupButton(
                ButtonType.OK
        );
        exitButton.setText("Exit");
        closeConfirmation.setHeaderText("Confirm Exit");
        closeConfirmation.initModality(Modality.APPLICATION_MODAL);
        closeConfirmation.initOwner(mainStage);

        // normally, you would just use the default alert positioning,
        // but for this simple sample the main stage is small,
        // so explicitly position the alert so that the main window can still be seen.
        closeConfirmation.setX(mainStage.getX());
        closeConfirmation.setY(mainStage.getY() + mainStage.getHeight());

        Optional<ButtonType> closeResponse = closeConfirmation.showAndWait();
        if (!ButtonType.OK.equals(closeResponse.get())) {
            event.consume();
        }
    };

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

}

如何触发内部关闭请求？

How can I fire internal close request?

java

javafx

javafx-2