C#关键字,explicit和implicit

这两个关键字可以在自己的类中,类型间转换时显式的还是隐式的

如下例子:

        public static implicit operator float(Currency value)
        {
            return value.dollars + (value.cents / 100.0f);
        }

        public static explicit operator Currency(float value)
        {
            checked
            {
                uint dollars = (uint)value;
                ushort cents = Convert.ToUInt16((value - dollars) * 100);
                return new Currency(dollars, cents);
            }
        }    

public static implicit operator float(Currency value)
表示Currency到float是隐式转换，如：
Currency a;
float b = a;

public static explicit operator Currency(float value)
表示float到Currency需要强制转换，如：
float a;
Currency b = (Currency)a;