编辑：如果用户单击“删除”以删除列表视图中的项目，我会弹出一个警报框。它有效，但我希望它能在原始舞台上弹出。它出现在我的第一台显示器上。有没有办法设置警报显示时的位置？
注意，“owner”在不同的类中，我用Scenebuilder/FXML创建了一切。我不知道如何让initOwner()工作。下面是“主”类:
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class Assignment_5 extends Application {
public Stage primaryStage;
@Override
public void start(Stage primaryStage) throws Exception{
Parent root = FXMLLoader.load(getClass().getResource("Assignment_5.fxml"));
primaryStage.setTitle("Plant Pack");
primaryStage.setScene(new Scene(root, 1200, 500));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
下面是控制器类中的工作代码。没有必要实现这个警报的模态，但是这将是一个很好的补充，使它更加方便。我只是不知道如何将主窗口从主类传递到这个:
protected void handleDeleteButtonClick(ActionEvent event) {
Alert alertBox = new Alert(Alert.AlertType.CONFIRMATION, "Confirm Delete", ButtonType.OK, ButtonType.CANCEL);
alertBox.setContentText("Are you sure you want to delete this " + plantType.getValue().toString().toLowerCase() + "?");
alertBox.showAndWait();
if(alertBox.getResult() == ButtonType.OK) {
int selectedPlant = plantList.getSelectionModel().getSelectedIndex();
observablePlantList.remove(selectedPlant);
}
else {
alertBox.close();
}
}
我知道这是相当新的，所以很难找到很多资源。如果有人知道任何我可能遗漏的信息，请告诉我。感谢提供的任何帮助。我用的是Java 8和IntelliJ 14.1.5。
正如@jewelsea所建议的，设置警报框的模式和所有者将确保警报将显示在舞台上，即使舞台被移动也是如此。
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.ButtonType;
import javafx.scene.control.ListView;
import javafx.scene.layout.BorderPane;
import javafx.stage.Modality;
import javafx.stage.Stage;
public class DeleteAlertDemo extends Application {
Stage owner;
ObservableList<String> observablePlantList;
ListView<String> plantList;
protected void handleDeleteButtonClick(ActionEvent event) {
String item = plantList.getSelectionModel().getSelectedItem();
Alert alertBox = new Alert(Alert.AlertType.CONFIRMATION, "Confirm Delete",
ButtonType.OK, ButtonType.CANCEL);
alertBox.setContentText("Are you sure you want to delete this "
+ item.toLowerCase() + "?");
alertBox.initModality(Modality.APPLICATION_MODAL); /* *** */
alertBox.initOwner(owner); /* *** */
alertBox.showAndWait();
if (alertBox.getResult() == ButtonType.OK) {
int selectedPlant = plantList.getSelectionModel().getSelectedIndex();
observablePlantList.remove(selectedPlant);
} else {
alertBox.close();
}
}
@Override
public void start(Stage primaryStage) {
owner = primaryStage; /* *** */
Button deleteBtn = new Button();
deleteBtn.setText("Delete");
deleteBtn.setOnAction(this::handleDeleteButtonClick);
observablePlantList = FXCollections.observableArrayList("Begonia",
"Peony", "Rose", "Lilly", "Chrysanthemum", "Hosta");
plantList = new ListView<>(observablePlantList);
plantList.getSelectionModel().select(0);
BorderPane root = new BorderPane();
root.setCenter(plantList);
root.setRight(deleteBtn);
Scene scene = new Scene(root, 300, 250);
primaryStage.setTitle("Delete Alert Demo");
primaryStage.setScene(scene);
primaryStage.show();
}
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
}
