JTabbedPane：在显示所选选项卡之前执行的操作 [英] JTabbedPane: Actions performed before displaying selected tab

问题描述

当点击 JTabbedPane 中的某个面板时，我需要在开始时执行一些操作。比如说，我需要检查用户名和密码。只有当这些匹配时，才需要执行特定的面板操作。你能建议任何方法吗？

When one of the panels present in a JTabbedPane is clicked, I need to perform a few actions at the start. Say, for example, I need to check the username and password. Only if those match, the particular panel operations need to be performed. Can you suggest any methods?

推荐答案

我不确定我是否完全理解你的问题，但我会这样做：

Not sure I fully understand your question, but I would do something like:

• 将一个ChangeListener添加到JTabbedPane以监听第一个标签点击。


• 当发生ChangeEvent时执行登录在使用SwingWorker的后台线程上。


• 如果登录成功，请在事件派发线程上执行所需的UI操作。

例如：

    tabbedPane.addChangeListener(new ChangeListener() {
    private boolean init;

    public void stateChanged(ChangeEvent e) {
        if (!init) {                                        
            init = true;

            new SwingWorker<Boolean, Void>() {
                @Override
                protected void done() {
                    try {
                        boolean loggedIn = get();

                        if (loggedIn) {
                            // Success so perform tab operations.
                        }
                    } catch (InterruptedException e1) {
                        e1.printStackTrace(); // Handle this.
                    } catch (ExecutionException e1) {
                        e1.printStackTrace(); // Handle this.
                    }
                }

                protected Boolean doInBackground() throws Exception {
                    // Perform login on background thread.  Return true if successful.
                    return true;
                }
            }.execute();
        }
        }
    });

这篇关于JTabbedPane：在显示所选选项卡之前执行的操作的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！