我是 JavaFX 编程的新手。我有一个应用程序，其中包含一个简单的登录页面，如此处示例中所述，我将 StringProperty 添加到 actiontarget 元素。因此，当 actiontarget 中的文本发生更改时，我想要一个内部带有 webview 的新 FXML 文件，从 FXMLLoader 加载并在屏幕上显示。下面是我得到的例外。我可以加载任何其他 fxml 文件，其中没有 webview，没有问题。在此先感谢。下面的代码示例异常：
java.lang.IllegalStateException: Not on FX application thread; currentThread = Thread-3
at com.sun.javafx.tk.Toolkit.checkFxUserThread(Toolkit.java:237)
at com.sun.javafx.tk.quantum.QuantumToolkit.checkFxUserThread(QuantumToolkit.java:397)
at com.sun.webpane.sg.prism.InvokerImpl.checkEventThread(InvokerImpl.java:33)
at com.sun.webpane.platform.WebPage.<init>(WebPage.java:189)
at com.sun.webpane.sg.ImplementationManager.createPage(ImplementationManager.java:57)
at com.sun.webpane.sg.ImplementationManager.createPage(ImplementationManager.java:51)
at javafx.scene.web.WebEngine.<init>(WebEngine.java:704)
at javafx.scene.web.WebEngine.<init>(WebEngine.java:691)
at javafx.scene.web.WebView.<init>(WebView.java:245)
at student.WebBrowser.<init>(WebBrowser.java:31)
at Login.Login.replaceSceneContent(Login.java:171)
at Login.Login.access$000(Login.java:66)
at Login.Login$2.changed(Login.java:143)
at Login.Login$2.changed(Login.java:137)
at com.sun.javafx.binding.ExpressionHelper$SingleChange.fireValueChangedEvent(ExpressionHelper.java:196)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:100)
at javafx.beans.property.StringPropertyBase.fireValueChangedEvent(StringPropertyBase.java:121)
at javafx.beans.property.StringPropertyBase.markInvalid(StringPropertyBase.java:128)
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:161)
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:67)
at javafx.scene.text.Text.setText(Text.java:188)
at Login.Client.run(Client.java:66)
首先我的听众：
// Add change listener
sp.addListener(new ChangeListener<String>() {
@Override
public void changed(ObservableValue<? extends String> ov, String t, String t1) {
if(t1.equalsIgnoreCase("user authenticated successfully")){
try {
replaceSceneContent(cb.getSelectionModel().getSelectedItem().toString()+".fxml",primaryStage);
System.out.println("everything ok");
} catch (Exception ex) {
System.out.println("something went wrong");
ex.printStackTrace();
}
}
}
});
第二个我的方法：replaceSceneContent(String fxml, Stage stage)
private Parent replaceSceneContent(String fxml, Stage stage) throws Exception {
Parent page = (Parent) FXMLLoader.load(getClass().getResource("/FXML_Files/"+fxml), null, new JavaFXBuilderFactory());
Scene scene = stage.getScene();
if (scene == null) {
scene = new Scene(page, 700, 450);
stage.setScene(scene);
} else {
stage.getScene().setRoot(page);
}
if(fxml.equalsIgnoreCase("Student.fxml")){
Pane spane = (Pane) page.lookup("#pane");
WebBrowser wb = new WebBrowser();
spane.getChildren().add(wb);
}
return page;
}
和我的 WebBrowser 类类似 NetBeans7.2 中的例子：
public class WebBrowser extends Pane {
public WebBrowser() {
WebView view;
final WebEngine eng;
view = new WebView();
view.setMinSize(10, 10);
view.setPrefSize(500, 400);
eng = view.getEngine();
eng.load("http://www.oracle.com/us/index.html");
VBox.setVgrow(this, Priority.ALWAYS);
setMaxWidth(Double.MAX_VALUE);
setMaxHeight(Double.MAX_VALUE);
final TextField locationField = new TextField("http://www.oracle.com/us/index.html");
locationField.setMaxHeight(Double.MAX_VALUE);
Button goButton = new Button("Go");
goButton.setDefaultButton(true);
EventHandler<ActionEvent> goAction = new EventHandler<ActionEvent>() {
@Override public void handle(ActionEvent event) {
eng.load(locationField.getText().startsWith("http://") ? locationField.getText() :
"http://" + locationField.getText());
}
};
goButton.setOnAction(goAction);
locationField.setOnAction(goAction);
eng.locationProperty().addListener(new ChangeListener<String>() {
@Override public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {
locationField.setText(newValue);
}
});
GridPane grid = new GridPane();
ButtonsEvents be = new ButtonsEvents();
TilePane tp = be;
tp.setAlignment(Pos.CENTER);
grid.setVgap(5);
grid.setHgap(5);
GridPane.setConstraints(locationField, 0, 0, 1, 1, HPos.CENTER, VPos.CENTER, Priority.ALWAYS, Priority.SOMETIMES);
GridPane.setConstraints(goButton,1,0);
GridPane.setConstraints(view, 0, 1, 2, 1, HPos.CENTER, VPos.CENTER, Priority.ALWAYS, Priority.ALWAYS);
GridPane.setConstraints(tp, 0, 2, 2, 1, HPos.CENTER, VPos.CENTER, Priority.ALWAYS, Priority.NEVER);
grid.getColumnConstraints().addAll(
new ColumnConstraints(100, 100, Double.MAX_VALUE, Priority.ALWAYS, HPos.CENTER, true),
new ColumnConstraints(40, 40, 40, Priority.ALWAYS, HPos.CENTER, true)
);
grid.getChildren().addAll(locationField, goButton,view, tp);
getChildren().add(grid);
}
@Override
protected void layoutChildren() {
List<Node> managed = getManagedChildren();
double width = getWidth();
double height = getHeight();
double top = getInsets().getTop();
double right = getInsets().getRight();
double left = getInsets().getLeft();
double bottom = getInsets().getBottom();
for (int i = 0; i < managed.size(); i++) {
Node child = managed.get(i);
layoutInArea(child, left, top,
width - left - right, height - top - bottom,
0, Insets.EMPTY, true, true, HPos.CENTER, VPos.CENTER);
}
}
}