这是一个使用DelphiXE编写的简单的计算器程序案例：
```delphi
program Calculator;
uses
SysUtils;
var
num1, num2: Double;
operator: Char;
result: Double;
begin
WriteLn('Welcome to the Calculator program!');
Write('Enter the first number: ');
ReadLn(num1);
Write('Enter the operator (+, -, *, /): ');
ReadLn(operator);
Write('Enter the second number: ');
ReadLn(num2);
case operator of
'+': result := num1 + num2;
'-': result := num1 - num2;
'*': result := num1 * num2;
'/': result := num1 / num2;
else
begin
WriteLn('Invalid operator!');
Exit;
end;
end;
WriteLn('The result is: ', result:0:2);
ReadLn;
end.
```
