package example;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class ui {
public String str1="",opt;
private JTextField display;
private calcultor CAL;
public ui(){
init();
}
public void init(){
JFrame f=new JFrame("计算器");
f.setLayout(new BorderLayout());
f.add(creatpane1(),BorderLayout.NORTH);
f.add(creatpane2(),BorderLayout.CENTER);
f.setSize(300,300);
f.setLocation(400,200);
f.setVisible(true);
}
public JPanel creatpane1(){
JPanel jp1=new JPanel();
jp1.setLayout(new BorderLayout());
display = new JTextField("0");
jp1.add(display);
return jp1;
}
private JPanel creatpane2(){
JPanel jp2=new JPanel();
jp2.setLayout(new GridLayout(4,4));
JButton button1=new JButton("1");
JButton button2=new JButton("2");
JButton button3=new JButton("3");
JButton add=new JButton("+");
JButton button4=new JButton("4");
JButton button5=new JButton("5");
JButton button6=new JButton("6");
JButton sub=new JButton("-");
JButton button7=new JButton("7");
JButton button8=new JButton("8");
JButton button9=new JButton("9");
JButton mul=new JButton("*");
JButton floa=new JButton(".");
JButton button0=new JButton("0");
JButton equal=new JButton("=");
JButton div=new JButton("/");
jp2.add(button1);
jp2.add(button2);
jp2.add(button3);
jp2.add(add);
jp2.add(button4);
jp2.add(button5);
jp2.add(button6);
jp2.add(sub);
jp2.add(button7);
jp2.add(button8);
jp2.add(button9);
jp2.add(mul);
jp2.add(floa);
jp2.add(button0);
jp2.add(equal);
jp2.add(div);
button1.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+button1.getText();
display.setText(str1);
}
});
button2.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+button2.getText();
display.setText(str1);
}
});
button3.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+button3.getText();
display.setText(str1);
}
});
button4.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+button4.getText();
display.setText(str1);
}
});
button5.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+button5.getText();
display.setText(str1);
}
});
button6.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+button6.getText();
display.setText(str1);
}
});
button7.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+button7.getText();
display.setText(str1);
}
});
button8.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+button8.getText();
display.setText(str1);
}
});
button9.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+button9.getText();
display.setText(str1);
}
});
button0.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+button0.getText();
display.setText(str1);
}
});
floa.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
str1=str1+".";
display.setText(str1);
}
});
add.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
opt="+";
setshow("");
str1="";
CAL.setopt(opt);
}
});
sub.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
opt="-";
setshow("");
str1="";
CAL.setopt(opt);
}
});
mul.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
opt="*";
setshow("");
str1="";
CAL.setopt(opt);//更新屏幕
}
});
div.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
opt="/";
CAL.setopt(opt);
}
});
equal.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
CAL.setanswer();
}
});
return jp2;
}
public double getshow(String str){
return Double.valueOf(str);
}
public void setshow(String str)
{
display.setText(str);
}
public String getopt(){
return this.opt;
}
public static void main(String[] args)
{
new ui();
}
}
这个是界面显示
package example;这个是功能实现 我的问题就是最后按等号得不出结果，想请问大家这是为什么，我是个新手，多多谅解
public class calcultor {
private double first,last,answer;
private ui UI;
public void setopt(String opt){
first = UI.getshow(UI.str1);
}
public void setanswer(){
last=UI.getshow(UI.str1);
if(UI.getopt()=="+")
{
answer=first+last;
UI.setshow(String.valueOf(answer));
}
else if(UI.getopt()=="-"){
answer=first-last;
UI.setshow(String.valueOf(answer));
}
else if(UI.getopt()=="*"){
answer=first*last;
UI.setshow(String.valueOf(answer));
}
else {
if(last==0) UI.setshow("输入有误");
else {
answer=first/last;
UI.setshow(String.valueOf(answer));
}
}
}
}
------解决思路----------------------
UI.getopt()=="-"
字符串比较要用equals方法，不是==:
"-".equals(UI.getopt())
------解决思路----------------------
有点乱，看了挺模糊的。
思路如下，点击按钮时候，计算机的text获取数字，点击计算加减乘除的时候，获取当前text的数值，将它赋值给一个临时变量。当用户按下等于号的时候，先获取计算方法，在获取第二次输入的值。根据计算方法把计算好的值赋进去。
封装，界面，计算方式，辅助。这三个类。
计算机界面 Ui.class
计算方式 Count.class
辅助 Util.class