c# - 操作可以泛化吗？

Question

我刚刚写了这段代码:

private double PerformOperation(OperationEnum operation, double aggregateValue, 
                                double sourceValue)
{
    if (operation == OperationEnum.Sum)
        return aggregateValue + sourceValue;
    if (operation == OperationEnum.Subtract)
        return aggregateValue - sourceValue;
    if (operation == OperationEnum.Multiply)
        return aggregateValue * sourceValue;
    if (operation == OperationEnum.Divide)
        return aggregateValue / sourceValue;
    throw new InvalidOperationException("Unsupported Aggregation Operation");
}

看起来很重复。有没有办法概括这一点？所以我不必有 4 条相同的线，只是符号不同？

(注:如果有更好的不使用OperationEnum的方法就好了)

Answer 1

你可以制作一个Dictionary<OperationEnum, Func<double, double, double>> :

static readonly Dictionary<OperationEnum, Func<double, double, double>> operations = 
    new Dictionary<OperationEnum, Func<double, double, double>> {
        { OperationEnum.Sum, (a, b) => a + b },
        ...
    };