package test
import java.awt.Color
import java.awt.Graphics
import java.awt.Graphics2D
import java.awt.event.ActionEvent
import java.awt.event.ActionListener
import javax.swing.JButton
import javax.swing.JFrame
import javax.swing.JLabel
import javax.swing.JPanel
import javax.swing.JTextField
import javax.swing.border.LineBorder
public class DrawFn extends JFrame{
private JTextField txt_interval
private JTextField txt_c
private JTextField txt_b
private JTextField txt_a
private drawFnPanel panel = new drawFnPanel()
/**
* @param args
*/
public static void main(String[] args) {
DrawFn frame=new DrawFn()
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)
frame.setVisible(true)
}
public DrawFn() {
super()
getContentPane().setLayout(null)
final JLabel aLabel = new JLabel()
aLabel.setText("a=")
aLabel.setBounds(10, 10, 21, 18)
getContentPane().add(aLabel)
txt_a = new JTextField()
txt_a.setBounds(31, 8, 87, 22)
getContentPane().add(txt_a)
final JLabel bLabel = new JLabel()
bLabel.setText("b=")
bLabel.setBounds(136, 10, 21, 18)
getContentPane().add(bLabel)
txt_b = new JTextField()
txt_b.setBounds(159, 8, 87, 22)
getContentPane().add(txt_b)
final JLabel cLabel = new JLabel()
cLabel.setText("c=")
cLabel.setBounds(267, 10, 32, 18)
getContentPane().add(cLabel)
txt_c = new JTextField()
txt_c.setBounds(290, 8, 87, 22)
getContentPane().add(txt_c)
final JLabel label = new JLabel()
label.setText("步长=")
label.setBounds(398, 10, 47, 18)
getContentPane().add(label)
txt_interval = new JTextField()
txt_interval.setBounds(440, 8, 87, 22)
getContentPane().add(txt_interval)
final JButton button = new JButton()
button.addActionListener(new draw_actionAdapter(this))
button.setText("绘制")
button.setBounds(533, 5, 61, 28)
getContentPane().add(button)
panel.setBorder(new LineBorder(Color.black, 1, false))
panel.setBounds(10, 36, 599, 389)
getContentPane().add(panel)
}
public void paintFn(ActionEvent e){
panel.paintFn(Integer.parseInt(txt_a.getText()), Integer.parseInt(txt_b.getText()), Integer.parseInt(txt_c.getText()), Integer.parseInt(txt_interval.getText()))
}
}
class drawFnPanel extends JPanel{
private int _a=0
private int _b=0
private int _c=0
private float _interval=0.01f
public void paintFn(int a,int b,int c,int interval){
_a=a
_b=b
_c=c
_interval=interval
repaint()
}
private double getY(float x){
return _a*x*x+_b*x+_c
}
public void paintComponent(Graphics g){
Graphics2D g2d=(Graphics2D)g
if(_a==0 &&_b==0 &&_c==0){
return
}
for(float i=-100fi<100fi=i+_interval){
g2d.drawRect((int)i, (int)getY(i), 1, 1)
}
}
}
class draw_actionAdapter implements ActionListener{
private DrawFn adapter
public draw_actionAdapter(DrawFn adapter){
this.adapter=adapter
}
public void actionPerformed(ActionEvent e) {
adapter.paintFn(e)
}
首先使用JXL读取excel的数据 然后使用JFreeChart把数据转成曲线图 说明: jxl.jar是通过java操作excel表格的工具类库支持Excel 95-2000的所有版本 JFreeChart是JAVA平台上的一个开放的图表绘制类库. 效果图
