当JavaFX中的选定选项卡更改时，如何聚焦特定节点? [英] How to focus a specific node when selected tab changes in JavaFX?

问题描述

我想将焦点设置到选项卡内容中的特定节点.我向 selectedItem 属性中添加了一个 ChangeListener ，如下所示(假设该类包含一个名为 secondNode 且类型为 Node 的字段):

I want to set focus to a specific node in the content of a Tab. I added a ChangeListener to selectedItem property as follows (assume that the class contains a field named secondNode of type Node):

tabPane.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<Tab>() {
    @Override
    public void changed(ObservableValue<? extends Tab> observable, Tab oldValue, Tab newValue) {
        if (newValue != null) {
            Platform.runLater(new Runnable() {
                @Override
                public void run() {
                    secondNode.requestFocus();
                }
            });
        }
    }
});

但是，这不起作用.我认为原因是因为在选择了新标签后，TabPane会执行一些其他操作，这些操作会影响焦点(但是，通过

However, this does not work. I assume the reason is because TabPane performs some additional actions, which affect focus, after the new tab has been selected (but, looking through TabPane source code, I can't figure out what). If I single-step through this code in a debugger, it works as expected, so it appears to be a race condition. If this is so, how can this be resolved?

推荐答案

您可以尝试将Runnable替换为Task:

You could try replacing the Runnable with a Task:

        new Thread( new Task<Void>() 
        {
            @Override
            public Void call() throws Exception // This is NOT on FX thread 
            {
                Thread.sleep(100);
                return null;
            }

            @Override
            public void succeeded()  // This is called on FX thread.
            {
                secondNode.requestFocus();
            }

        }).start();

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