java中如何改变计算器颜色_计算器+改变窗口颜色

package 界面;

import java.awt.*;

import java.awt.GridLayout;

import java.awt.event.*;

import java.awt.BorderLayout;

import javax.swing.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;public classCalculator implements ActionListener {

JFrame f;

JPanel p;

JPanel p1;

JTextField t;

JButton b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,delete;

GridLayout g1;

String nowButton;publicCalculator(){

f=newJFrame();

g1=new GridLayout(5,4);

p=newJPanel();

p.setLayout(g1);

t=newJTextField();

b1=new JButton("7");b2=new JButton("8");b3=new JButton("9");b4=new JButton("/");

b5=new JButton("4");b6=new JButton("5");b7=new JButton("6");b8=new JButton("*");

b9=new JButton("1");b10=new JButton("2");b11=new JButton("3");b12=new JButton("-");

b13=new JButton("0");b14=new JButton(".");b15=new JButton("=");b16=new JButton("+");

delete=new JButton("C");

b1.addActionListener(this);b2.addActionListener(this);

b3.addActionListener(this);b4.addActionListener(this);

b5.addActionListener(this);b6.addActionListener(this);

b7.addActionListener(this);b8.addActionListener(this);

b9.addActionListener(this);b10.addActionListener(this);

b11.addActionListener(this);b12.addActionListener(this);

b13.addActionListener(this);b14.addActionListener(this);

b15.addActionListener(this);b16.addActionListener(this);

delete.addActionListener(this);

p.add(b1);p.add(b2);p.add(b3);p.add(b4);p.add(b5);p.add(b6);p.add(b7);

p.add(b8);p.add(b9);p.add(b10);p.add(b11);p.add(b12);p.add(b13);p.add(b14);

p.add(b15);p.add(b16);p.add(delete);

f.add(t,BorderLayout.NORTH);

f.add(p,BorderLayout.CENTER);

f.setSize(400,300);

f.setVisible(true);

}public static voidmain(String[] args) {newCalculator();

}public voidactionPerformed(ActionEvent e) {

nowButton=e.getActionCommand();if (nowButton != "=") {

t.setText(t.getText()+nowButton);

}if (nowButton.equals("=")) {

t.setText(jisuan(t.getText()));

}if (nowButton.equals("C")) {

t.setText("0.0");

}

}public String jisuan(String string) {

StringBuffer sb= new StringBuffer(string);int commandCount = 0;//符号数量

int j = 0;//计数器

for (j = 0; j < sb.length(); j++) {if (sb.charAt(j) <= '9' && sb.charAt(j) >= '0' || sb.charAt(j) == '.') {continue;

}else{

commandCount++;

}

}char[] command = new char[commandCount];//初始化符号数组//初始化数字数组(用字符串表示)

String[] num = new String[commandCount+1];//计算有多少个运算符，就有n+1个数字

for (j = 0; j < num.length; j++) {

num[j]= "";

}//遍历一遍，吧每个数字存进数字数组，每个符号存进符号数组

int k = 0;for (j = 0; j < sb.length(); j++) {if (sb.charAt(j) <= '9' && sb.charAt(j) >= '0' || sb.charAt(j) == '.') {

num[k]+= sb.charAt(j);//用charAt()装运算符和数字

continue;

}else{

command[k]=sb.charAt(j);

k++;

}

}double result = 0;for (int i = 0; i < commandCount; i++) {//取前两个数，和第一个操作符，运算

double num1 = Double.parseDouble(num[i]);//把字符串转换为Double

double num2 = Double.parseDouble(num[i+1]);char c1 =command[i];//计算

switch(c1) {case '+':

result= num1 +num2;break;case '-':

result= num1 -num2;break;case '*':

result= num1 *num2;break;case '/':

result= num1 /num2;break;default:break;

}

num[i+1] = String.valueOf(result);//将double 变量转换成字符串

}returnString.valueOf(result);

}

}