import java.awt.*;
public class BorderLayout {
public static void main (String []args) {
Frame frame = new Frame("this is a test");
Button b1 = new Button("north");
Button b2 = new Button("west");
Button b3 = new Button("south");
Button b4 = new Button("east");
Button b5 = new Button("center");
frame.add(b1,BorderLayout.NORTH);
frame.add(b2,BorderLayout.WEST);
frame.add(b3,BorderLayout.SOUTH);
frame.add(b4,BorderLayout.EAST);
frame.add(b5,BorderLayout.CENTER);
frame.setSize(400,400);
frame.setLocation(0,0);
frame.setBackground(Color.red);
frame.setVisible(true);
}
}
在命令行提示符中编译时提示变量NORTH,SOUTH,WEST,EAST,CENTER找不到符号,是怎么回事?