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採取例13-3「實現細胞工廠」從 http://docs.oracle.com/javafx/2/ui_controls/tree-view.htm 並添加線簡單JavaFX的事件處理程序拋出異常
box.addEventHandler(EventType.ROOT, new EventHandler<Event>() {
@Override
public void handle(Event event) {
System.out.println("event "+event);
}
});
在啓動方法則以下的例外將當雙擊 拋出僱員節點：
java.lang.ClassCastException: javafx.scene.layout.VBox cannot be cast to javafx.scene.control.TreeView
at javafx.scene.control.TreeView$EditEvent.getSource(TreeView.java:988)
at javafx.scene.control.TreeView$EditEvent.getSource(TreeView.java:965)
at com.sun.javafx.event.EventHandlerManager.fixEventSource(EventHandlerManager.java:225)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:216)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:28)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Node.fireEvent(Node.java:6863)
at javafx.scene.control.TreeCell.startEdit(TreeCell.java:315)
at test.TreeViewSample$TextFieldTreeCellImpl.startEdit(TreeViewSample.java:100)
at javafx.scene.control.TreeCell.updateEditing(TreeCell.java:435)
at javafx.scene.control.TreeCell.access$500(TreeCell.java:67)
at javafx.scene.control.TreeCell$6.invalidated(TreeCell.java:151)
at javafx.beans.WeakInvalidationListener.invalidated(WeakInvalidationListener.java:80)
at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:359)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:100)
at javafx.beans.property.ReadOnlyObjectWrapper$ReadOnlyPropertyImpl.fireValueChangedEvent(ReadOnlyObjectWrapper.java:195)
at javafx.beans.property.ReadOnlyObjectWrapper.fireValueChangedEvent(ReadOnlyObjectWrapper.java:161)
at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:130)
at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:163)
at javafx.scene.control.TreeView.setEditingItem(TreeView.java:573)
at javafx.scene.control.TreeView.edit(TreeView.java:771)
at com.sun.javafx.scene.control.behavior.TreeCellBehavior.simpleSelect(TreeCellBehavior.java:257)
at com.sun.javafx.scene.control.behavior.TreeCellBehavior.doSelect(TreeCellBehavior.java:213)
at com.sun.javafx.scene.control.behavior.TreeCellBehavior.mouseReleased(TreeCellBehavior.java:132)
at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:336)
at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:329)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:64)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:33)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3328)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3168)
at javafx.scene.Scene$MouseHandler.access$1900(Scene.java:3123)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1563)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2265)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:250)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:173)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:292)
at com.sun.glass.ui.View.handleMouseEvent(View.java:528)
at com.sun.glass.ui.View.notifyMouse(View.java:922)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:29)
at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:73)
at java.lang.Thread.run(Unknown Source)
這是一個錯誤還是我有什麼問題？
完整的示例代碼（需要包含的文件在同一目錄「root.png」和「department.png」）：
package test;
import java.util.*;
import javafx.application.*;
import javafx.beans.property.*;
import javafx.event.*;
import javafx.scene.*;
import javafx.scene.control.*;
import javafx.scene.image.*;
import javafx.scene.input.*;
import javafx.scene.layout.*;
import javafx.scene.paint.*;
import javafx.stage.*;
import javafx.util.*;
public class TreeViewSample extends Application {
private final Node rootIcon =
new ImageView(new Image(getClass().getResourceAsStream("root.png")));
private final Image depIcon =
new Image(getClass().getResourceAsStream("department.png"));
List<Employee> employees = Arrays.<Employee>asList(
new Employee("Ethan Williams", "Sales Department"),
new Employee("Emma Jones", "Sales Department"),
new Employee("Michael Brown", "Sales Department"),
new Employee("Anna Black", "Sales Department"),
new Employee("Rodger York", "Sales Department"),
new Employee("Susan Collins", "Sales Department"),
new Employee("Mike Graham", "IT Support"),
new Employee("Judy Mayer", "IT Support"),
new Employee("Gregory Smith", "IT Support"),
new Employee("Jacob Smith", "Accounts Department"),
new Employee("Isabella Johnson", "Accounts Department"));
TreeItem<String> rootNode =
new TreeItem<String>("MyCompany Human Resources", rootIcon);
public static void main(String[] args) {
Application.launch(args);
}
@Override
public void start(Stage stage) {
rootNode.setExpanded(true);
for (Employee employee : employees) {
TreeItem<String> empLeaf = new TreeItem<String>(employee.getName(), new ImageView(depIcon));
boolean found = false;
for (TreeItem<String> depNode : rootNode.getChildren()) {
if (depNode.getValue().contentEquals(employee.getDepartment())){
depNode.getChildren().add(empLeaf);
found = true;
break;
}
}
if (!found) {
TreeItem<String> depNode = new TreeItem<String>(
employee.getDepartment(),
new ImageView(depIcon)
);
rootNode.getChildren().add(depNode);
depNode.getChildren().add(empLeaf);
}
}
stage.setTitle("Tree View Sample");
VBox box = new VBox();
final Scene scene = new Scene(box, 400, 300);
scene.setFill(Color.LIGHTGRAY);
TreeView<String> treeView = new TreeView<String>(rootNode);
treeView.setEditable(true);
treeView.setCellFactory(new Callback<TreeView<String>,TreeCell<String>>(){
@Override
public TreeCell<String> call(TreeView<String> p) {
return new TextFieldTreeCellImpl();
}
});
box.getChildren().add(treeView);
stage.setScene(scene);
stage.show();
box.addEventHandler(EventType.ROOT, new EventHandler<Event>() {
@Override
public void handle(Event event) {
System.out.println("event "+event);
}
});
}
private final class TextFieldTreeCellImpl extends TreeCell<String> {
private TextField textField;
public TextFieldTreeCellImpl() {
}
@Override
public void startEdit() {
super.startEdit();
if (textField == null) {
createTextField();
}
setText(null);
setGraphic(textField);
textField.selectAll();
}
@Override
public void cancelEdit() {
super.cancelEdit();
setText((String) getItem());
setGraphic(getTreeItem().getGraphic());
System.out.println(" item canceled "+getItem());
}
@Override
public void updateItem(String item, boolean empty) {
super.updateItem(item, empty);
if (empty) {
setText(null);
setGraphic(null);
} else {
if (isEditing()) {
if (textField != null) {
textField.setText(getString());
}
setText(null);
setGraphic(textField);
} else {
setText(getString());
setGraphic(getTreeItem().getGraphic());
}
}
}
private void createTextField() {
textField = new TextField(getString());
textField.setOnKeyReleased(new EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent t) {
if (t.getCode() == KeyCode.ENTER) {
commitEdit(textField.getText());
} else if (t.getCode() == KeyCode.ESCAPE) {
cancelEdit();
}
}
});
}
private String getString() {
return getItem() == null ? "" : getItem().toString();
}
}
public static class Employee {
private final SimpleStringProperty name;
private final SimpleStringProperty department;
private Employee(String name, String department) {
this.name = new SimpleStringProperty(name);
this.department = new SimpleStringProperty(department);
}
public String getName() {
return name.get();
}
public void setName(String fName) {
name.set(fName);
}
public String getDepartment() {
return department.get();
}
public void setDepartment(String fName) {
department.set(fName);
}
}
}