Javafx 2 应用程序和控制器类之间的JavaFXML通信
我试图获取并销毁我在FXML应用程序close中通过ProcessBuilder创建的外部进程,但它不起作用。这是基于有用的建议 我尝试过在子类顶部和底部使用“//myController.setApp(this);”和“//super.stop();”(请参阅MyApp中注释掉/插入的那一行),但没有任何组合可以工作 这可能与FXML或JavaFX无关,尽管我认为这是在JavaFX上开发应用程序的常见模式。我想我要的是一个Java最佳实践,用于关闭基于UI的应用程序中的依赖进程,比如这个应用程序(在本例中为:FXML/JavaFX-based),其中有一个控制器类和一个应用程序类 你能解释一下我做错了什么吗?或者更好:建议我应该做什么?谢谢 在我的应用程序中,我执行以下操作:Javafx 2 应用程序和控制器类之间的JavaFXML通信,javafx-2,processbuilder,fxml,Javafx 2,Processbuilder,Fxml,我试图获取并销毁我在FXML应用程序close中通过ProcessBuilder创建的外部进程,但它不起作用。这是基于有用的建议 我尝试过在子类顶部和底部使用“//myController.setApp(this);”和“//super.stop();”(请参阅MyApp中注释掉/插入的那一行),但没有任何组合可以工作 这可能与FXML或JavaFX无关,尽管我认为这是在JavaFX上开发应用程序的常见模式。我想我要的是一个Java最佳实践,用于关闭基于UI的应用程序中的依赖进程,比如这个应用程
public class MyApp extends Application {
@Override
public void start(Stage primaryStage) throws Exception {
FXMLLoader fxmlLoader = new FXMLLoader();
Scene scene = (Scene)FXMLLoader.load(getClass().getResource("MyApp.fxml"));
MyAppController myController = (MyAppController)fxmlLoader.getController();
primaryStage.setScene(scene);
primaryStage.show();
// myController.setApp(this);
}
@Override
public void stop() throws Exception {
// super.stop();
// this is called on fx app close, you may call it in an action handler too
if (MyAppController.getScriptProcess() != null) {
MyAppController.getScriptProcess().destroy();
}
super.stop();
}
public static void main(String[] args) {
launch(args);
}
}
public class MyAppController implements Initializable {
private Application app;
private static Process scriptProcess;
public void setApp(Application a) {
app = a;
}
public static Process getScriptProcess() {
return scriptProcess;
}
}
在我的控制器中,我执行以下操作:
public class MyApp extends Application {
@Override
public void start(Stage primaryStage) throws Exception {
FXMLLoader fxmlLoader = new FXMLLoader();
Scene scene = (Scene)FXMLLoader.load(getClass().getResource("MyApp.fxml"));
MyAppController myController = (MyAppController)fxmlLoader.getController();
primaryStage.setScene(scene);
primaryStage.show();
// myController.setApp(this);
}
@Override
public void stop() throws Exception {
// super.stop();
// this is called on fx app close, you may call it in an action handler too
if (MyAppController.getScriptProcess() != null) {
MyAppController.getScriptProcess().destroy();
}
super.stop();
}
public static void main(String[] args) {
launch(args);
}
}
public class MyAppController implements Initializable {
private Application app;
private static Process scriptProcess;
public void setApp(Application a) {
app = a;
}
public static Process getScriptProcess() {
return scriptProcess;
}
}
当我使用未注释掉的“注释掉的setApp()”运行时(即,保留在start方法中),结果如下:启动后立即(主场景闪烁,然后消失,然后出现此对话框):
"JavaFX Launcher Error:
Exception while running Application"
它在控制台中也给出了一个“应用程序启动方法中的异常”
当我在上面MyApp中省略“注释掉的代码”(即从start方法中删除“setApp()”)时,结果是我的应用确实关闭了,但在关闭时会出现以下错误:
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1440)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:69)
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.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.Button.fire(Button.java:179)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:193)
at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:336)
at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:329)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:64)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:33)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3324)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3164)
at javafx.scene.Scene$MouseHandler.access$1900(Scene.java:3119)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1559)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2261)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:228)
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.gtk.GtkApplication._runLoop(Native Method)
at com.sun.glass.ui.gtk.GtkApplication$3$1.run(GtkApplication.java:82)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1435)
... 44 more
Caused by: java.lang.NullPointerException
at mypackage.MyController.handleCancel(MyController.java:300)
... 49 more
Clean up...
方法是正确的,但问题很少 您已经创建了名为
fxmloader
的fxmloader
,但随后调用了fxmloader.load()
,它是静态方法,不与您以前创建的实例连接
另外,使用静态方法进行交互也不是很好(假设您需要几个进程)。最好将myController
存储到一个字段中,并在stop()
方法中调用它
更好的做法是将相应的实用程序方法添加到控制器中,并从主应用程序调用它,因为主应用程序似乎不使用进程本身
下面是一个简短的应用程序,用于演示所描述的所有内容:
public class DoTextAreaLog extends Application {
private LoggController controller;
@Override
public void start(Stage stage) throws IOException{
FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("logg.fxml"));
VBox root = (VBox)fxmlLoader.load();
controller = (LoggController) fxmlLoader.getController();
stage.setScene(new Scene(root, 400, 300));
stage.show();
}
@Override
public void stop() throws Exception {
super.stop();
controller.destroy();
}
public static void main(String[] args) { launch(); }
}
控制器:
public class LoggController implements Initializable {
@FXML private TextArea textarea;
@FXML private void onAction(ActionEvent event) {
destroy();
}
private Process p;
public void destroy() {
if (p != null) {
p.destroy();
}
}
@Override
public void initialize(URL url, ResourceBundle rb) {
try {
p = new ProcessBuilder("ping", "stackoverflow.com", "-n", "100").start();
new Thread(new Runnable() {
@Override
public void run() {
try {
try (BufferedReader bri = new BufferedReader(new InputStreamReader(p.getInputStream()))) {
String line;
while ((line = bri.readLine()) != null) {
log(line);
}
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
}).start();
} catch (IOException ex) {
ex.printStackTrace();
}
}
private void log(final String st) {
Platform.runLater(new Runnable() {
@Override
public void run() {
textarea.setText(st + "\n" + textarea.getText());
}
});
}
}
logg.fxml:
<VBox id="root" prefHeight="400.0" prefWidth="600.0" xmlns:fx="http://javafx.com/fxml" fx:controller="fxml.LoggController">
<TextArea fx:id="textarea"/>
<Button text="Stop The Madness!" onAction="#onAction"/>
</VBox>
方法是正确的,但问题很少 您已经创建了名为
fxmloader
的fxmloader
,但随后调用了fxmloader.load()
,它是静态方法,不与您以前创建的实例连接
另外,使用静态方法进行交互也不是很好(假设您需要几个进程)。最好将myController
存储到一个字段中,并在stop()
方法中调用它
更好的做法是将相应的实用程序方法添加到控制器中,并从主应用程序调用它,因为主应用程序似乎不使用进程本身
下面是一个简短的应用程序,用于演示所描述的所有内容:
public class DoTextAreaLog extends Application {
private LoggController controller;
@Override
public void start(Stage stage) throws IOException{
FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("logg.fxml"));
VBox root = (VBox)fxmlLoader.load();
controller = (LoggController) fxmlLoader.getController();
stage.setScene(new Scene(root, 400, 300));
stage.show();
}
@Override
public void stop() throws Exception {
super.stop();
controller.destroy();
}
public static void main(String[] args) { launch(); }
}
控制器:
public class LoggController implements Initializable {
@FXML private TextArea textarea;
@FXML private void onAction(ActionEvent event) {
destroy();
}
private Process p;
public void destroy() {
if (p != null) {
p.destroy();
}
}
@Override
public void initialize(URL url, ResourceBundle rb) {
try {
p = new ProcessBuilder("ping", "stackoverflow.com", "-n", "100").start();
new Thread(new Runnable() {
@Override
public void run() {
try {
try (BufferedReader bri = new BufferedReader(new InputStreamReader(p.getInputStream()))) {
String line;
while ((line = bri.readLine()) != null) {
log(line);
}
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
}).start();
} catch (IOException ex) {
ex.printStackTrace();
}
}
private void log(final String st) {
Platform.runLater(new Runnable() {
@Override
public void run() {
textarea.setText(st + "\n" + textarea.getText());
}
});
}
}
logg.fxml:
<VBox id="root" prefHeight="400.0" prefWidth="600.0" xmlns:fx="http://javafx.com/fxml" fx:controller="fxml.LoggController">
<TextArea fx:id="textarea"/>
<Button text="Stop The Madness!" onAction="#onAction"/>
</VBox>
FXMLLoader FXMLLoader=new FXMLLoader(getClass().getResource(“logg.fxml”);对我不起作用,我收到一个错误,没有适合FXMLLoader(URL)的构造函数,虽然有。我不明白原因。请将此作为一个单独的问题提问,提供您的代码、完整的异常和您正在使用的JavaFX版本。FXMLLoader FXMLLoader=new FXMLLoader(getClass().getResource(“logg.fxml”);对我不起作用,我收到一个错误,FXMLLoader(URL)没有合适的构造函数,虽然有。我不明白这是什么原因。请将此作为一个单独的问题提问,提供您的代码、完整的异常和您正在使用的JavaFX版本。