确定如何在C#中将对象强制转换为适当类型的最佳方法？

Question

我目前正在开发批准路由WCF服务,该服务允许用户创建"规则",以确定如何路由请求.通过将Request类的"ObjectToEvaluate"属性与"Rule"类的"ObjectToEvaluate"属性进行比较来确定路由."UnitOfMeasurement"枚举确定如何为每个类强制转换"ObjectToEvaluate"属性.

public enum UnitOfMeasurement
{
    Currency = 1,
    Numeric = 2,
    Special = 3,
    Text = 4,
}

public class Request
{
    public object ObjectToEvaluate { get; set; }
}

public class Rule
{
    public object ObjectToEvaluate { get; set; }

    public virtual void ExecuteRule()
    {
        //logic to see if it passes the rule condition
    }
}

使用"UnitOfMeasurement"枚举实现方法来转换"ObjectToEvaluate"属性的最佳方法是什么？

Answer 1

使用隐式类型运算符来检查枚举的值.这样,调用者可以透明地将对象分配给您想要表示它们的类型.例如:

public class CastableObject {

    private UnitOfMeasurement eUnit; // Assign this somehow

    public static implicit operator int(CastableObject obj) 
    {
        if (obj.eUnit != UnitOfMeasurement.Numeric)
        {
            throw new InvalidCastException("Mismatched unit of measurement");
        }
        // return the numeric value
    }

    // Create other cast operators for the other unit types
}