Java panel画图程序的问题
程序一直都不画图形 找不到什么原因 求大牛指点～
//test.javapackage jwindows;import java.awt.Color;import java.awt.Graphics;import java.util.Random;import javax.swing.JPanel;public class Test extends JPanel { int x1, x2, y1, y2; public static Random a = new Random(); public void paintComponent(Graphics g) { super.paintComponent(g); //g.fillArc(x, y, width, height, startAngle, arcAngle) g.setColor(Color.CYAN); g.drawLine(1, 1, 30, 30); int i = 0; while (i <= hi.num) { x1 = a.nextInt(this.getWidth()); y1 = a.nextInt(this.getHeight()); hi.xing[i].draw(g, x1, y1); i++; } } int type;}//hi.javapackage jwindows;import java.awt.Color;import javax.swing.JFrame;import javax.swing.JOptionPane;public class hi { public static Shape[] xing = new Shape[10]; public static int num = 0; public static void main(String args[]) { int i = 0; while (i < 10) { String hi = JOptionPane .showInputDialog("Please type 1 for Circle\nPlease type 2 for Rectangle\nPlease type 0 to exit\n"); int type = Integer.parseInt(hi); if (type == 0) break; switch (type) { case 1: xing[num] = new Circle(); break; case 2: xing[num] = new Rectangle(); break; default: { JOptionPane.showMessageDialog(null, "Error!"); num--; break; } } // xing.draw(g); num++; } JFrame app = new JFrame(); app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); app.setTitle("DrawBoard"); Test panel = new Test(); panel.setBackground(Color.WHITE); app.add(panel); app.setSize(200, 400); app.setVisible(true); }}//Shape.java 图形继承的基类 子类有rectangle circlepublic abstract class Shape { abstract public void init(); //abstract public double area(); //abstract public void display(); public abstract void draw(Graphics g,int dx,int dy); //public abstract void ram(); Scanner input=new Scanner(System.in);// }