谁能帮我解决这个问题 这个图形总是不能显示在画布上 我纠结啊 我做了很久没有做出来。大家帮帮忙，你们可以到Eclipse运行，我描述问题能力有限 谢谢大
package Test;import java.awt.Canvas;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JTextField;
public class jisuan {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
new pwx();
}
}
class pwx extends JFrame implements ActionListener{
Canvas c;
//public final double PI=3.14f;
JRadioButton tuoyuan,juxing;
JTextField t1,t2,t3,t4;
JButton bt;
JLabel l1,l2,l3,l4;
int lt1,lt2;
public pwx(){
super("图形计算");
Dimension di=getToolkit().getScreenSize();
this.setBounds(di.width/4, di.height/4, di.width/2, di.height/2);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
JPanel jp=new JPanel();
this.getContentPane().add(jp,"West");
JPanel dx=new JPanel(new GridLayout(1,2));
jp.add(dx);
ButtonGroup bg=new ButtonGroup();
juxing=new JRadioButton("矩形",true);
bg.add(juxing);
dx.add(juxing);
tuoyuan=new JRadioButton("椭圆");
bg.add(tuoyuan);
dx.add(tuoyuan);
l1=new JLabel("长度");
t1=new JTextField(10);
jp.add(l1);
jp.add(t1);
l2=new JLabel("宽度");
t2=new JTextField(10);
jp.add(l2);
jp.add(t2);
bt=new JButton("绘图");
jp.add(bt);
JPanel jp1=new JPanel();
this.getContentPane().add(jp1,"South");
l3=new JLabel("周长");
t3=new JTextField(10);
jp1.add(l3);
jp1.add(t3);
l4=new JLabel("面积");
t4=new JTextField(10);
jp1.add(l4);
jp1.add(t4);
//c=new Canvas(Color.red);
//this.getContentPane().add(c,"Center");
//jp.add(c);
bt.addActionListener(this);
juxing.addActionListener(this);
tuoyuan.addActionListener(this);
this.setVisible(true);
}
@Override
public void actionPerformed(ActionEvent a) {
// TODO Auto-generated method stub
if(a.getSource()==bt||a.getSource()==juxing){
//try{
double cd=Double.parseDouble(t1.getText());
double kd=Double.parseDouble(t2.getText());
t3.setText(String.valueOf(cd*2+kd*2));
t4.setText(String.valueOf(cd*kd));
}
//lt1=(int)cd;
//lt2=(int)kd;
//c=new Canvas(lt1,lt2);
// }
//catch(Exception e){}
if(a.getSource()==bt&a.getSource()==tuoyuan)
{
double cd1=Double.parseDouble(t1.getText());
double kd1=Double.parseDouble(t2.getText());
t3.setText(String.valueOf(2*3.14f*(kd1+cd1)));
t4.setText(String.valueOf(3.14f*(kd1+cd1)));
}
}
class pw extends Canvas{
Color co;
public pw(Color co){
//this.setColor(co);
}
public void paint(Graphics g){
g.setColor(Color.black);
g.fillRect(this.getWidth()/2,this.getHeight()/2, 100, 300);
g.setColor(Color.black);
g.fillOval(this.getWidth()/2,this.getHeight()/2, 100, 300);
}
}
}
