java代码写亲戚计算器 java的计算器代码( 三 )


buttonequal.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// 该判断中间变量是否为空
if (!"".equals(sBuilder.toString())(!(a == 0.0))) {
b = Double.parseDouble(sBuilder.toString());
if (i == 0) {
double1 = a + b;
label.setText(double1.toString());
sBuilder = new StringBuilder();
sBuilder.append(double1);
} else if (i == 1) {
double1 = a - b;
label.setText(double1.toString());
sBuilder = new StringBuilder();
sBuilder.append(double1);
} else if (i == 2) {
double1 = a * b;
label.setText(double1.toString());
sBuilder = new StringBuilder();
sBuilder.append(double1);
} else if (i == 3) {
double1 = a / b;
label.setText(double1.toString());
sBuilder = new StringBuilder();
sBuilder.append(double1);
} else {
label.setText(sBuilder.toString());
}
}
}
});
buttondecimal.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
sBuilder.append(".");
label.setText(sBuilder.toString());
}
});
buttonclear.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
sBuilder = new StringBuilder();
label.setText("");
}
});
buttondelet.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (!"".equals(sBuilder.toString())) {
sBuilder.deleteCharAt(sBuilder.length() - 1);
label.setText(sBuilder.toString());
}
}
});
this.setVisible(true);
}
public static void main(String[] args) {
new CaculatorDemo();
}
}
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原文链接:
怎么用JAVA编程编写一个计算器?打开IED:打开自己java编程的软件,采用的是eclipse软件 。
建立java工程 。
编写类 。
编写类的详细步骤
1.类的基本结构:
由于这里用到了界面,所以要进行窗口界面的编程,按钮事件的处理,和计算处理界面;
package MyCaculator;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MyCaculator extends JFrame {
private int add=1,sub=2,mul=3,div=4;
private int op=0;
boolean ifOp;
private String output="0";
private Button[] jba=new Button[]{new Button("7"),new Button("8"),
new Button("9"),new Button("+"),
new Button("4"),new Button("5"),new Button("6"),new Button("-"),
new Button("1"),new Button("2"),new Button("3"),new Button("*"),
new Button("0"),new Button("."),new Button("="),new Button("/")};
private JPanel jpt=new JPanel();
private JPanel jpb=new JPanel();
private JTextField jtf=new JTextField("");
private MyCaculator(){
}
private void operate(String x){
}
public String add(String x){
return output;
}
public String subtract(String x){
return output;
}
public String multiply(String x){
return output;
}
public String divide(String x){
return output;
}
public String Equals(String x){
return output;
}
public void opClean(){
}
class setOperate_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
}
}
class setLabel_Act implements ActionListener{
public void actionPerformed(ActionEvent e) {
}
}
public static void main(String[] args) {
}
}
2.建立构造方法:
所谓构造方法就是,对自己的主类进行初始化,代码如下:

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