BlueJ：找不到类CanvasPane

Question

当我尝试在BlueJ中使用类CanvasPane时，它会抛出一个编译错误，说＆＃34;找不到符号 - 类CanvasPane＆＃34;即使我添加这些导入：

import javax.swing.*;
import java.awt.*;

可能是什么问题？

Answer 1

以下套餐不包含CanvasPane

    import javax.swing.*;
    import java.awt.*;

选中此URL，CanvasPane是BlueJ.java中的私有内部类，您无法导入它。否则，您可以定义自己的canvasPane并将其嵌入到您的 public class MyClass{ private CanvasPane myCanvasPane; public class CanvasPane extends JPanel { public void paint(Graphics g) { g.drawImage(canvasImage, 0, 0, null); } } } 中类：

Attempt to unlock a mutex which is locked by another thread