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Question

当我运行这个程序时：

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

public class DrawApplet extends JApplet{

    public void init () {

        Container content_pane = getContentPane ();
        // Create an instance of DrawingPanel
        int x=1000, y=1000;

        content_pane.setSize(x, y);

        // And add the DrawingPanel to the content pane.
        main_panel drawing_panel = new main_panel(x,y);
        content_pane.add(drawing_panel);
    }
}

显示错误：

DrawApplet.java:16: error: cannot find symbol
main_panel drawing_panel = new main_panel(x,y);
     ^
symbol:   class main_panel
location: class DrawApplet
DrawApplet.java:16: error: cannot find symbol
main_panel drawing_panel = new main_panel(x,y);
                                    ^
symbol:   class main_panel
location: class DrawApplet
2 errors

Answer 1

my是您创建的课程吗？如果是这样，它不遵循典型的命名标准 - 因为类应以大写字母开头。它在类路径上吗？

此外，您的错误与您发布的代码（my与main_panel）不符。确保您的文件和构建是最新的。