Question

我想做以下事情：

点击按钮
将矩形颜色设为
等待1秒
颜色为矩形蓝色

在以下代码中：

GraphicsContext gc;
Button myButton = new Button("Button!");
myButton.setOnAction(new EventHandler<ActionEvent>(){
        @Override
        public void handle(ActionEvent event){
            SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    gc.setFill(Color.RED);
                    gc.fillRect(0, 0, 100, 100);
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                    }
                    gc.setFill(Color.BLUE);
                    gc.fillRect(0, 0, 100, 100);
                }
            });
        }
    });

这很好用。它创建一个0,0的红色框，宽度和宽度为0。高度为100.但是当我尝试修改一个标签时，它会崩溃。

GraphicsContext gc;
Pane root = new Pane();
Button myButton = new Button("Button!");
Label myLabel = new Label("HELLO!"); // added
root.getChildren.add(myLabel);
myButton.setOnAction(new EventHandler<ActionEvent>(){
        @Override
        public void handle(ActionEvent event){
            SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    gc.setFill(Color.RED);
                    gc.fillRect(0, 0, 100, 100);
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                    }
                    gc.setFill(Color.BLUE);
                    gc.fillRect(0, 0, 100, 100);
                    myLabel.setText("WORLD!"); // modified here
                }
            });
        }
    });

我期待的结果是，

点击按钮
将矩形颜色设为
等待1秒
将矩形颜色设为
然后更改HELLO的标签文字！世界！

但是我收到了错误。为什么会这样？我可以不修改SwingUtilities中的任何Pane元素吗？

任何建议都会有所帮助。

修改

这是我按下按钮时出现的错误

Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: Not on FX application thread; currentThread = AWT-EventQueue-0
at com.sun.javafx.tk.Toolkit.checkFxUserThread(Toolkit.java:229)
at com.sun.javafx.tk.quantum.QuantumToolkit.checkFxUserThread(QuantumToolkit.java:423)
at javafx.scene.Parent$2.onProposedChange(Parent.java:367)
at com.sun.javafx.collections.VetoableListDecorator.setAll(VetoableListDecorator.java:113)
at com.sun.javafx.collections.VetoableListDecorator.setAll(VetoableListDecorator.java:108)
at com.sun.javafx.scene.control.skin.LabeledSkinBase.updateChildren(LabeledSkinBase.java:575)
at com.sun.javafx.scene.control.skin.LabeledSkinBase.handleControlPropertyChanged(LabeledSkinBase.java:204)
at com.sun.javafx.scene.control.skin.LabelSkin.handleControlPropertyChanged(LabelSkin.java:49)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase.lambda$registerChangeListener$61(BehaviorSkinBase.java:197)
at com.sun.javafx.scene.control.MultiplePropertyChangeListenerHandler$1.changed(MultiplePropertyChangeListenerHandler.java:55)
at javafx.beans.value.WeakChangeListener.changed(WeakChangeListener.java:89)
at com.sun.javafx.binding.ExpressionHelper$SingleChange.fireValueChangedEvent(ExpressionHelper.java:182)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
at javafx.beans.property.StringPropertyBase.fireValueChangedEvent(StringPropertyBase.java:103)
at javafx.beans.property.StringPropertyBase.markInvalid(StringPropertyBase.java:110)
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:144)
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:49)
at javafx.beans.property.StringProperty.setValue(StringProperty.java:65)
at javafx.scene.control.Labeled.setText(Labeled.java:145)
at Lego$1$1.run(Lego.java:63)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

Answer 1

这是因为任何Java FX components必须由JavaFX Application Thread管理，因为它们不是线程安全的（这与任何Swing components必须完全相同的原因由AWT event dispatching Thread管理，因此您需要使用Platform.runLater(runnable)作为下一个间接修改您的标签：

使用Java 8

Platform.runLater(() -> myLabel.setText("WORLD!"));

使用以前版本的Java

Platform.runLater(new Runnable() {
        public void run() {
            myLabel.setText("WORLD!"); 
        }
    }
);

我们使用SwingUtilities.invokeLater(runnable)让AWT event dispatching thread执行一些将在未来某个未指定的时间修改Swing components的代码，如果Platform.runLater(runnable)与Java FX components相同Swing。

NB：仅使用Java FX个组件或仅使用Swing个组件，除非您没有其他选择，否则请避免混用JavaFX和lm(1_T1 ~ CRP, data = exposure)个组件。

Answer 2

永远不要暂停JFXAT，不要在它上面睡觉，你要杀死响应，创建一个线程，在它上面睡觉，然后在里面使用Platform.runLater来更新UI。

updateLbl(){
    new Thread(new Runnable(){
         Thread.sleep();//sleep //try catch
         Platform.runLater ... //inside update ui
    }).start();
}

Javafx修改＆＃34;标签＆＃34;在SwingUtilities.invokeLater中

2 个答案: