java计算器代码下载 java编写简单计算器代码( 五 )

jt1.setText("" + op1);
} else {
currentOp = preOp;
preOp = 2;
switch (currentOp) {
case 1:
op1 = op1 + op2;
jt1.setText("" + op1);
break;
case 2:
op1 = op1 - op2;
jt1.setText("" + op1);
break;
case 3:
op1 = op1 * op2;
jt1.setText("" + op1);
break;
case 4:
op1 = op1 / op2;
jt1.setText("" + op1);
break;
}
}
} else if (s.equals("*"))// *
{
str.setLength(0);
if (currentOp == 0) {
preOp = currentOp = 3;// op1=op2;op2=1;
jt1.setText("" + op1);// op1=op2;
} else {
currentOp = preOp;
preOp = 3;
switch (currentOp) {
case 1:
op1 = op1 + op2;
jt1.setText("" + op1);
break;
case 2:
op1 = op1 - op2;
jt1.setText("" + op1);
break;
case 3:
op1 = op1 * op2;
jt1.setText("" + op1);
break;
case 4:
op1 = op1 / op2;
jt1.setText("" + op1);
break;
}
}
} else if (s.equals("/"))// /
{
str.setLength(0);
if (currentOp == 0) {
preOp = currentOp = 4;// op2=1;
jt1.setText("" + op1);// op1=op2;
} else {
currentOp = preOp;
preOp = 4;
switch (currentOp) {
case 1:
op1 = op1 + op2;
jt1.setText("" + op1);
break;
case 2:
op1 = op1 - op2;
jt1.setText("" + op1);
break;
case 3:
op1 = op1 * op2;
jt1.setText("" + op1);
break;
case 4:
op1 = op1 / op2;
jt1.setText("" + op1);
break;
}
}
} else if (s.equals("="))// =
{
if (currentOp == 0) {
str.setLength(0);
jt1.setText("" + op2);
} else {
str.setLength(0);
currentOp = preOp;
switch (currentOp) {
case 1:
op1 = op1 + op2;
jt1.setText("" + op1);
break;
case 2:
op1 = op1 - op2;
jt1.setText("" + op1);
break;
case 3:
op1 = op1 * op2;
jt1.setText("" + op1);
break;
case 4:
op1 = op1 / op2;
jt1.setText("" + op1);
break;
}
currentOp = 0;
op2 = 0;
}
} else if (s.equals(".")) {
isDouble = true;
if (jt1.getText().trim().indexOf('.') != -1)
;
else {
if (jt1.getText().trim().equals("0")) {
str.setLength(0);
jt1.setText((str.append("0" + s)).toString());
}
// else
// if(jt1.getText().trim().equals("")){}//如果初时显示为空则不做任何操作
else {
jt1.setText((str.append(s)).toString());
}
}
} else if (s.equals("0"))// 如果选择的是"0"这个数字键
{
if (jt1.getText().trim().equals("0.")) {
} else {
jt1.setText(str.append(s).toString());
op2 = Double.parseDouble(jt1.getText().trim());
}
} else {
jt1.setText(str.append(s).toString());
op2 = Double.parseDouble(jt1.getText().trim());
if (currentOp == 0)
op1 = op2;
}
}
public static void main(String args[])
{
JPanelEa1 g=new JPanelEa1();
}
@Override
public void menuSelected(MenuEvent e) {
// TODO Auto-generated method stub
}
@Override
public void menuDeselected(MenuEvent e) {
// TODO Auto-generated method stub
}
@Override
public void menuCanceled(MenuEvent e) {
// TODO Auto-generated method stub
}
}
下载的java源代码怎么打开.class文件是java编译后的文件，它不是源代码，真正的java源代码是.java文件。
java源代码是txt格式的.java文件，用记事本就可以打开。
用eclipse打开java文件的方式是：
如果java文件是一个eclipse工程（根目录带有.project文件），用file/import/general/exist java project/（大概是）然后找到你的目录。