更新:如需最新教程,请咨询the official documentation。在 2.2 中添加了很多 new stuff。此外,Introduction to FXML 涵盖了您需要了解的有关 FXML 的几乎所有内容。最后,Hendrik Ebbers 就自定义 UI 控件提供了非常有帮助的 blog post。
在查看API 并阅读一些文档(Intro to FXML、Getting started with FXMLProperty binding、Future of FXML)几天后,我想出了一个相当明智的解决方案。
我从这个小实验中学到的最不直接的信息是控制器的实例(在 FXML 中用 fx:controller 声明)由加载 FXML 文件的FXMLLoader 持有......最糟糕的是,这个在我看到的所有文档中,one place 只提到了重要的事实:
控制器通常只对创建它的 FXML 加载器可见
因此,请记住,为了以编程方式(从 Java 代码)获取对在 FXML 中使用 fx:controller 声明的控制器实例的引用,请使用 FXMLLoader.getController()(请参阅下面的 ChoiceCell 类的实现完整的例子)。
另外需要注意的是Property.bindBiderctional() 会将调用属性的值设置为作为参数传入的属性的值。给定两个布尔属性target(最初设置为false)和source(最初设置为true)调用target.bindBidirectional(source)会将target的值设置为true。显然,对任一属性的任何后续更改都会更改另一个属性的值(target.set(false) 将导致 source 的值设置为 false):
BooleanProperty target = new SimpleBooleanProperty();//value is false
BooleanProperty source = new SimpleBooleanProperty(true);//value is true
target.bindBidirectional(source);//target.get() will now return true
target.set(false);//both values are now false
source.set(true);//both values are now true
不管怎样,这里有完整的代码展示了 FXML 和 Java 如何协同工作(以及其他一些有用的东西)
包结构:
com.example.javafx.choice
ChoiceCell.java
ChoiceController.java
ChoiceModel.java
ChoiceView.fxml
com.example.javafx.mvc
FxmlMvcPatternDemo.java
MainController.java
MainView.fxml
MainView.properties
FxmlMvcPatternDemo.java
package com.example.javafx.mvc;
import java.util.ResourceBundle;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class FxmlMvcPatternDemo extends Application
{
public static void main(String[] args) throws ClassNotFoundException
{
Application.launch(FxmlMvcPatternDemo.class, args);
}
@Override
public void start(Stage stage) throws Exception
{
Parent root = FXMLLoader.load
(
FxmlMvcPatternDemo.class.getResource("MainView.fxml"),
ResourceBundle.getBundle(FxmlMvcPatternDemo.class.getPackage().getName()+".MainView")/*properties file*/
);
stage.setScene(new Scene(root));
stage.show();
}
}
MainView.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import java.lang.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<VBox
xmlns:fx="http://javafx.com/fxml"
fx:controller="com.example.javafx.mvc.MainController"
prefWidth="300"
prefHeight="400"
fillWidth="false"
>
<children>
<Label text="%title" />
<ListView fx:id="choicesView" />
<Button text="Force Change" onAction="#handleForceChange" />
</children>
</VBox>
MainView.properties
title=JavaFX 2.0 FXML MVC demo
MainController.java
package com.example.javafx.mvc;
import com.example.javafx.choice.ChoiceCell;
import com.example.javafx.choice.ChoiceModel;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.collections.FXCollections;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
import javafx.util.Callback;
public class MainController implements Initializable
{
@FXML
private ListView<ChoiceModel> choicesView;
@Override
public void initialize(URL url, ResourceBundle rb)
{
choicesView.setCellFactory(new Callback<ListView<ChoiceModel>, ListCell<ChoiceModel>>()
{
public ListCell<ChoiceModel> call(ListView<ChoiceModel> p)
{
return new ChoiceCell();
}
});
choicesView.setItems(FXCollections.observableArrayList
(
new ChoiceModel("Tiger", true),
new ChoiceModel("Shark", false),
new ChoiceModel("Bear", false),
new ChoiceModel("Wolf", true)
));
}
@FXML
private void handleForceChange(ActionEvent event)
{
if(choicesView != null && choicesView.getItems().size() > 0)
{
boolean isSelected = choicesView.getItems().get(0).isSelected();
choicesView.getItems().get(0).setSelected(!isSelected);
}
}
}
ChoiceView.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import java.lang.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<HBox
xmlns:fx="http://javafx.com/fxml"
fx:controller="com.example.javafx.choice.ChoiceController"
>
<children>
<CheckBox fx:id="isSelectedView" />
<Label fx:id="labelView" />
</children>
</HBox>
ChoiceController.java
package com.example.javafx.choice;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.CheckBox;
import javafx.scene.control.Label;
public class ChoiceController
{
private final ChangeListener<String> LABEL_CHANGE_LISTENER = new ChangeListener<String>()
{
public void changed(ObservableValue<? extends String> property, String oldValue, String newValue)
{
updateLabelView(newValue);
}
};
private final ChangeListener<Boolean> IS_SELECTED_CHANGE_LISTENER = new ChangeListener<Boolean>()
{
public void changed(ObservableValue<? extends Boolean> property, Boolean oldValue, Boolean newValue)
{
updateIsSelectedView(newValue);
}
};
@FXML
private Label labelView;
@FXML
private CheckBox isSelectedView;
private ChoiceModel model;
public ChoiceModel getModel()
{
return model;
}
public void setModel(ChoiceModel model)
{
if(this.model != null)
removeModelListeners();
this.model = model;
setupModelListeners();
updateView();
}
private void removeModelListeners()
{
model.labelProperty().removeListener(LABEL_CHANGE_LISTENER);
model.isSelectedProperty().removeListener(IS_SELECTED_CHANGE_LISTENER);
isSelectedView.selectedProperty().unbindBidirectional(model.isSelectedProperty())
}
private void setupModelListeners()
{
model.labelProperty().addListener(LABEL_CHANGE_LISTENER);
model.isSelectedProperty().addListener(IS_SELECTED_CHANGE_LISTENER);
isSelectedView.selectedProperty().bindBidirectional(model.isSelectedProperty());
}
private void updateView()
{
updateLabelView();
updateIsSelectedView();
}
private void updateLabelView(){ updateLabelView(model.getLabel()); }
private void updateLabelView(String newValue)
{
labelView.setText(newValue);
}
private void updateIsSelectedView(){ updateIsSelectedView(model.isSelected()); }
private void updateIsSelectedView(boolean newValue)
{
isSelectedView.setSelected(newValue);
}
}
ChoiceModel.java
package com.example.javafx.choice;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
public class ChoiceModel
{
private final StringProperty label;
private final BooleanProperty isSelected;
public ChoiceModel()
{
this(null, false);
}
public ChoiceModel(String label)
{
this(label, false);
}
public ChoiceModel(String label, boolean isSelected)
{
this.label = new SimpleStringProperty(label);
this.isSelected = new SimpleBooleanProperty(isSelected);
}
public String getLabel(){ return label.get(); }
public void setLabel(String label){ this.label.set(label); }
public StringProperty labelProperty(){ return label; }
public boolean isSelected(){ return isSelected.get(); }
public void setSelected(boolean isSelected){ this.isSelected.set(isSelected); }
public BooleanProperty isSelectedProperty(){ return isSelected; }
}
ChoiceCell.java
package com.example.javafx.choice;
import java.io.IOException;
import java.net.URL;
import javafx.fxml.FXMLLoader;
import javafx.fxml.JavaFXBuilderFactory;
import javafx.scene.Node;
import javafx.scene.control.ListCell;
public class ChoiceCell extends ListCell<ChoiceModel>
{
@Override
protected void updateItem(ChoiceModel model, boolean bln)
{
super.updateItem(model, bln);
if(model != null)
{
URL location = ChoiceController.class.getResource("ChoiceView.fxml");
FXMLLoader fxmlLoader = new FXMLLoader();
fxmlLoader.setLocation(location);
fxmlLoader.setBuilderFactory(new JavaFXBuilderFactory());
try
{
Node root = (Node)fxmlLoader.load(location.openStream());
ChoiceController controller = (ChoiceController)fxmlLoader.getController();
controller.setModel(model);
setGraphic(root);
}
catch(IOException ioe)
{
throw new IllegalStateException(ioe);
}
}
}
}