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829天前import java.awt.*; |
import java.awt.event.*; |
import javax.swing.*; |
public class Chp13_1 extends JFrame{ |
private JButton jisuan; |
private JPanel panel1,panel2,panel3,panel4; |
private JTextField field1,field2,field3; |
private JLabel label1,label2,label3,label4; |
private JTextArea area; |
private Container container; |
|
Chp13_1(){ |
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super("计算一元二次方程的根"); |
container = getContentPane(); |
container.setLayout(new FlowLayout()); |
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label4 = new JLabel("请依次输入一元二次方程的三个系数，并点击计算显示实根"); |
container.add(label4); |
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panel1 = new JPanel(); |
label1 = new JLabel("系数a"); |
field1 = new JTextField(10); |
panel1.add(label1); |
panel1.add(field1); |
|
panel2 = new JPanel(); |
label2 = new JLabel("系数b"); |
field2 = new JTextField(10); |
panel2.add(label2); |
panel2.add(field2); |
|
panel3 = new JPanel(); |
label3 = new JLabel("系数c"); |
field3 = new JTextField(10); |
panel3.add(label3); |
panel3.add(field3); |
|
panel4 = new JPanel(); |
panel4.setLayout(new GridLayout(1,3,1,2)); |
panel4.add(panel1); |
panel4.add(panel2); |
panel4.add(panel3); |
container.add(panel4); |
|
jisuan = new JButton("计算"); |
jisuan.addActionListener( |
new ActionListener(){ |
public void actionPerformed(ActionEvent event) { |
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double a = Double.parseDouble(field1.getText()); |
double b = Double.parseDouble(field2.getText()); |
double c = Double.parseDouble(field3.getText()); |
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double deerta = b*b-4*a*c; |
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if(deerta < 0){ |
area.setText("无实根"); |
}else { |
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double x1 = (Math.sqrt(deerta)-b)/(2*a); |
double x2 = (-Math.sqrt(deerta)-b)/(2*a); |
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area.setText("实根1 = "+x1+"\n实根2 = "+x2); |
} |
} |
} |
); |
|
|
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container.add(jisuan); |
|
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area = new JTextArea(10,15); |
area.setText("该方程的实根为"); |
container.add(area); |
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setSize(500,400); |
setVisible(true); |
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} |
|
public static void main(String[] args) { |
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Chp13_1 application = new Chp13_1(); |
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); |
|
} |
|
} |
