static void Main(string[] args) { Director director = new Director(); //构造加法运算 BinaryOperationBuilder addBinaryOperationBuilder = new AddBinaryOperationBuilder(); director.BuildBinaryOperation(addBinaryOperationBuilder); BinaryOperation addBinaryOperation = addBinaryOperationBuilder.GetBinaryOperation(); addBinaryOperation.Show(); //构造减法运算 BinaryOperationBuilder subBinaryOperationBuilder = new SubBinaryOperationBuilder(); director.BuildBinaryOperation(subBinaryOperationBuilder); BinaryOperation subBinaryOperation = subBinaryOperationBuilder.GetBinaryOperation(); subBinaryOperation.Show(); Console.ReadKey(); }