Question

你能否帮我解决这个错误。我一直试图弄清楚这里的问题在哪里。也许是我没见过的东西。这是一个非常简单的程序。我没有太多java经验。

这是代码。

public class StudentInfo extends Application {
@Override // Override the start method in the Application class
  public void start(Stage primaryStage) {
    // Create a pane and set its properties

    BorderPane mainpane = new BorderPane();
    GridPane leftpane = new GridPane();
    leftpane.setAlignment(Pos.CENTER);
    leftpane.setPadding(new Insets(11.5, 12.5, 13.5, 14.5));
    leftpane.setHgap(5);
    leftpane.setVgap(5.5);
    //FlowPane pane = new FlowPane(Orientation.VERTICAL);
    //pane.setPadding(new Insets(11, 12, 13, 14));
    //pane.setHgap(5);
    //pane.setVgap(5);

    //String[] computerCourses = {"Select a course","Python", "C#", "Dephi","Java","XML"};
    //String[] businessCourses = {"Select a course","Finance","Marketing","Investment Analysis","Business Communications"};

    // Place nodes in the pane

    Label lblName = new Label("Name:");
    Label lblAddress = new Label("Adress:");
    Label lblProvince = new Label("Province");
    Label lblCity = new Label("City:");
    Label lblPostalCode = new Label("Postal Code:");
    Label lblPhoneNumber = new Label("Phone number:");
    Label lblEmail = new Label("Email:");

    //VBox vBox = new VBox(5);
    //vBox.setPadding(new Insets(15, 5, 5, 5));
    //vBox.getChildren().add(lblName);
    //vBox.getChildren().add(lblAddress);
    //vBox.getChildren().add(lblProvince);
    //vBox.getChildren().add(lblCity);
    //vBox.getChildren().add(lblPostalCode);
    //vBox.getChildren().add(lblPhoneNumber);
    //vBox.getChildren().add(lblEmail);

    //mainpane.setLeft(vBox);
    TextField tfName = new TextField();
    TextField tfAddress = new TextField();
    TextField tfProvince = new TextField();
    TextField tfCity = new TextField();
    TextField tfPostalCode = new TextField();
    TextField tfPhoneNumber = new TextField();
    TextField tfEmail = new TextField();

    leftpane.add(lblName, 0, 0);
    leftpane.add(tfName, 1, 0);
    leftpane.add(lblAddress, 0, 1); 
    leftpane.add(tfAddress, 1, 1);
    leftpane.add(lblProvince, 0, 2);
    leftpane.add(tfProvince, 1, 2);
    leftpane.add(lblPhoneNumber, 0, 3);
    leftpane.add(tfPhoneNumber, 1, 3);
    leftpane.add(lblCity, 0, 4);
    leftpane.add(tfCity, 1, 4);
    leftpane.add(lblPostalCode, 0, 5);
    leftpane.add(tfPostalCode, 1, 5);
    leftpane.add(lblPhoneNumber, 0, 6);
    leftpane.add(tfPhoneNumber, 1, 6);
    leftpane.add(lblEmail, 0, 7);
    leftpane.add(tfEmail, 1, 7);

    mainpane.setLeft(leftpane);
    //Button btDisplay = new Button("Display");

    //CheckBox chkStudentCouncil = new CheckBox("Bold");
    //CheckBox chkVolunteerWork = new CheckBox("Bold");

    //RadioButton rbComputerScience = new RadioButton("Computer Science");
    //RadioButton rbBusiness = new RadioButton("Business"); 
    //ComboBox<String> cbCourses = new ComboBox<>();
    //ListView<String> lvCourses = new ListView<>(); 
    //pane.getChildren().addAll(lblName, lblAddress, lblProvince, lblCity, lblPostalCode, lblPhoneNumber, lblEmail); 

    // Create a scene and place it in the stage
    Scene scene = new Scene(mainpane, 1000, 300);
    primaryStage.setTitle("Student Information"); // Set the stage title
    primaryStage.setScene(scene); // Place the scene in the stage
    primaryStage.show(); // Display the stage
  }

  /**
   * The main method is only needed for the IDE with limited
   * JavaFX support. Not needed for running from the command line.
   */
  public static void main(String[] args) {
    launch(args);
  }

}

这是错误。

Exception in Application start method
java.lang.reflect.InvocationTargetException

    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

    at java.lang.reflect.Method.invoke(Unknown Source)

    at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(Unknown Source)

    at com.sun.javafx.application.LauncherImpl.launchApplication(Unknown Source)

    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

    at java.lang.reflect.Method.invoke(Unknown Source)

    at sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)

Caused by: java.lang.RuntimeException: Exception in Application start method

    at com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)

    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$147(Unknown Source)

    at com.sun.javafx.application.LauncherImpl$$Lambda$48/128893786.run(Unknown Source)

    at java.lang.Thread.run(Unknown Source)

Caused by: java.lang.IllegalArgumentException: Children: duplicate children added: parent = Grid hgap=5.0, vgap=5.5, alignment=CENTER

    at javafx.scene.Parent$2.onProposedChange(Unknown Source)

    at com.sun.javafx.collections.VetoableListDecorator.add(Unknown Source)

    at javafx.scene.layout.GridPane.add(Unknown Source)

    at StudentInfo.start(StudentInfo.java:71)

    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$153(Unknown Source)

    at com.sun.javafx.application.LauncherImpl$$Lambda$51/488112689.run(Unknown Source)

    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$166(Unknown Source)

    at com.sun.javafx.application.PlatformImpl$$Lambda$45/1051754451.run(Unknown Source)

    at com.sun.javafx.application.PlatformImpl.lambda$null$164(Unknown Source)

    at com.sun.javafx.application.PlatformImpl$$Lambda$47/1184297595.run(Unknown Source)

    at java.security.AccessController.doPrivileged(Native Method)

    at com.sun.javafx.application.PlatformImpl.lambda$runLater$165(Unknown Source)

    at com.sun.javafx.application.PlatformImpl$$Lambda$46/1775282465.run(Unknown Source)

    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)

    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)

    at com.sun.glass.ui.win.WinApplication.lambda$null$141(Unknown Source)

    at com.sun.glass.ui.win.WinApplication$$Lambda$37/1109371569.run(Unknown Source)
        ... 1 more
    Exception running application StudentInfo

提前感谢你们的任何帮助

Answer 1

问题在于：

leftpane.add(lblPhoneNumber, 0, 6);
leftpane.add(tfPhoneNumber, 1, 6);

您已经添加了lblPhoneNumber，此处：

leftpane.add(lblPhoneNumber, 0, 3);
leftpane.add(tfPhoneNumber, 1, 3);

异常Caused by: java.lang.IllegalArgumentException: Children: duplicate children added只是试图告诉您，您无法在网格的另一个位置再次添加同一个对象。

javafx中java.lang.reflect.InvocationTargetException中的异常

1 个答案: