java - 更改 Java 图形对象的颜色

Question

我正在尝试通过更改颜色并调用 repaint() 方法来刷新 Java 图形对象。颜色仅随着最终更改颜色调用而更新。这是我的代码:

public void start() {
    try {
        Color origColor = node.getColor();
        for (int i=0; i<noOfFlashes; i++) {
            Manager.gui.getDrawGraph().changeNodeColor(node, Color.WHITE);
            Thread.sleep(500);
            Manager.gui.getDrawGraph().changeNodeColor(node, origColor);
            Thread.sleep(500);
        }
        Manager.gui.getDrawGraph().changeNodeColor(node, Graph.VISITED_NODE);       
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

改变节点颜色的方法是:

public void changeNodeColor(Node node, Color c) {
    node.setColor(c);
    repaint();
}

更改节点颜色与绘制组件属于同一类。

任何帮助将不胜感激。

Answer 1

您需要使用单独的线程来管理 GUI 事件。 您可以使用SwingWorker来做到这一点，按照 Amine 的建议，或实现 Runnable接口(interface)，或扩展Thread类，开发 run()方法，那就是你的线程的任务。

您可以阅读SO的这个老问题:How do I use SwingWorker in Java?

SwingWorker 教程:http://docs.oracle.com/javase/tutorial/uiswing/concurrency/worker.html

创建主题的教程:http://docs.oracle.com/javase/tutorial/essential/concurrency/

The color is only updating with the final change color call.

如果你不使用单独的线程，你的 gui 将卡住，直到该方法完全执行，并且你不会看到由 Thread.sleep(500); 分隔的颜色变化。 .

更新

在 this链接，在为什么 Swing GUI 卡住或锁定？段落中，您可以通过使用单线程来理解为什么 Java Swing GUI 卡住。

另请检查this官方链接，在创建线程段落中，以及this页面，返回:

Swing's single-thread rule says that Swing components can only be accessed by a single thread. This rule applies to both gets and sets, and the single thread is known as the event-dispatch thread.

The single-thread rule is a good match for UI components because they tend to be used in a single-threaded way anyway, with most actions being initiated by the user. Furthermore, building thread safe components is difficult and tedious: it's a good thing not to be doing if it can be avoided. But for all its benefits, the single-thread rule has far-reaching implications.

Swing components will generally not comply with the single-thread rule unless all their events are sent and received on the event-dispatch thread. For example, property-change events should be sent on the event-dispatch thread, and model-change events should be received on the event-dispatch thread.

For model-based components such as JTable and JTree, the single-thread rule implies that the model itself can only be accessed by the event-dispatch thread. For this reason, the model's methods must execute quickly and should never block, or the entire user interface will be unresponsive.

我认为上面的句子对于更好地理解Swing非常有用。包。

我报告了trashgod的建议。

您可以使用Timer类，来自javax.swing.Timer包裹。这也是一个不错的选择。

在 this问题，trashgod 报告了一些 Timer 的例子.

检查here有关 Timer 的教程.