JavaFX2.0 超链接Hyperlink.doc

Hyperlink类呈现的是Labeled控件的另一种形式，主要用来格式化超链接文本。Figure 17-1显示了默认超链接的三个实现状态。Figure 17-1 Three States of a Hyperlink ControlDescription of Figure 17-1 Three States of a Hyperlink Control创建Hyperlink这些代码将产生上面的效果Example 17-1.Example 17-1 Typical HyperlinkHyperlink link = new Hyperlink(); link.setText(); link.setOnAction(new EventHandler() Override public void handle(ActionEvent e) System.out.println(This link is clicked); );setText实例方法定义了超链接的文本。由于Hyperlink类继承了Labeled类，所以可以为超链接指定特定的字体和内容。setOnAction方法定义了任何时候点击超链接的行为，和Button控件很像。在Example 17-1中，这种行为只是用来打印一个字符串。实际上，它可以实现更多更复杂的认为。连接到本地内容Figure 17-2中的应用显示了本地的图片。Figure 17-2 Viewing ImagesDescription of Figure 17-2 Viewing Images看下它的代码Example 17-2.Example 17-2 Using Hyperlinks to VIew Imagesimport javafx.application.Application; import javafx.event.ActionEvent; import javafx.event.EventHandler; import javafx.scene.*; import javafx.scene.control.*; import javafx.scene.image.Image; import javafx.scene.image.ImageView; import javafx.scene.layout.VBox; import javafx.stage.Stage; public class Main extends Application final static String imageFiles = new String product.png, education.png, partners.png, support.png ; final static String captions = new String Products, Education, Partners, Support ; final ImageView selectedImage = new ImageView(); final ScrollPane list = new ScrollPane(); final Hyperlink hpls = new Hyperlinkcaptions.length; final Image images = new ImageimageFiles.length; public static void main(String args) Application.launch(args); Override public void start(Stage stage) Scene scene = new Scene(new Group(); stage.setTitle(Hyperlink Sample); stage.setWidth(300); stage.setHeight(200); selectedImage.setLayoutX(100); selectedImage.setLayoutY(10); for (int i = 0; i captions.length; i+) final Hyperlink hpl = hplsi = new Hyperlink(captionsi); final Image image = imagesi = new Image( getClass().getResourceAsStream(imageFilesi) ); hpl.setOnAction(new EventHandler() Override public void handle(ActionEvent e) selectedImage.setImage(image); ); final Button button = new Button(Refresh links); button.setOnAction(new EventHandler() Override public void handle(ActionEvent e) for (int i = 0; i captions.length; i+) hplsi.setVisited(false); selectedImage.setImage(null); ); VBox vbox = new VBox(); vbox.getChildren().addAll(hpls); vbox.getChildren().add(button); vbox.setSpacing(5); (Group) scene.getRoot().getChildren().addAll(vbox, selectedImage); stage.setScene(scene); stage.show(); 该应用在for循环中创建了四个Hyperlink对象。点击特点的超链接会调用setOnAction方法产生不同的行为。这样，images数组中相应的图片就设置给selectedImage变量。当点击一个超链接时，它就成为了访问过的（visited）。可以使用Hyperlink类的setVisited方法刷新链接。见Example 17-3中的代码。Example 17-3 Refreshing the HyperlInksfinal Button button = new Button(Refresh links); button.setOnAction(new EventHandler() Override public void handle(ActionEvent e) for (int i = 0; i captions.length; i+) hplsi.setVisited(false); selectedImage.setImage(null); );点击Refresh Links按钮就会就把超链接都充值为未访问状态。见Figure 17-3.Figure 17-3 Unvisited HyperlinksDescription of Figure 17-3 Unvisited Hyperlinks由于Hyperlink类继承了Labeled类，所以除了文本还可以为其指定图片。下一部分的应用就使用了文本和图片链接并加载远程HTML页面。链接到远程内容可以在JavaFX应用中显示HTML内容，方法是在场景内绑定WebView浏览器。WebView组件提供了网页的基本浏览功能。除此之外，还支持用户交互，如导航和执行JavaScript命令。研究Example 17-4中的代码，它创建了带有文本和图像的超链接。点击超链接后，相应的值就作为URL传递给绑定的浏览器。Example 17-4 Loading Remote Web Pagesimport javafx.application.Application; import javafx.event.ActionEvent; import javafx.event.EventHandler; import javafx.scene.*; import javafx.scene.control.*; import javafx.scene.image.Image; import javafx.scene.image.ImageView; import javafx.scene.layout.HBox; import javafx.scene.layout.Priority; import javafx.scene.layout.VBox; import javafx.scene.text.Font; import javafx.scene.web.WebEngine; import javafx.scene.web.WebView; import javafx.stage.Stage; public class Main extends Application final static String imageFiles = new String product.png, education.png, partners.png, support.png ; final static String captions = new String Products, Education, Partners, Support ; final static String urls = new String /us/products/index.html, /, /partners/index.html, /us/support/index.html ; final ImageView selectedImage = new ImageView(); final Hyperlink hpls = new Hyperlinkcaptions.length; final Image images = new ImageimageFiles.length; public static void main(String args) launch(args); Override public void start(Stage stage) VBox vbox = new VBox(); Scene scene = new Scene(vbox); stage.setTitle(Hyperlink Sample); stage.setWidth(570); stage.setHeight(550); selectedImage.setLayoutX(100); selectedImage.setLayoutY(10); final WebView browser = new WebView(); final WebEngine webEngine = browser.getEngine(); for (int i = 0; i captions.length; i+) final Hyperlink hpl = hplsi = new Hyperlink(captionsi); final Image image = imagesi = new Image(getClass().getResourceAsStream(imageFilesi); hpl.setGraphic(new ImageView (image); hpl.setFont(Font.font(Arial, 14); final String url = urlsi; hpl.setOnAction(new EventHandler() Override public void handle(ActionEvent e) webEngine.load(url); ); HBox hbox = new HBox(); hbox.getChildren().addAll(hpls); vbox.getChildren().addAll(hbox, browser); VBox.setVgrow(brows