在C＃和返回类型条件运算 [英] Conditional operator in C# and return types

问题描述

可能显示的文件：结果
的为什么空需要在这里投了明确的类型？结果
的可空类型和三元运营商。 ？为什么不这项工作

试图做到以下几点：

sqlCmd.Parameters.Add("@DateCreated", System.Data.SqlDbType.DateTime).Value 
    = myObject.DateCreated == DateTime.MinValue 
    ? DBNull.Value : myObject.DateCreated;

我得到这个错误：

I am getting this error:

条件表达式类型
，因为有
间'System.DBNull'和'System.DateTime的

Type of conditional expression cannot be determined because there is no implicit conversion between 'System.DBNull' and 'System.DateTime'

我明明知道错误，但为什么连型此事鉴于Parameters.Value是类型的对象？有没有办法来完成我所试图做的？

I obviously understand the error but why does type even matter given that Parameters.Value is of type object? Is there a way to accomplish what I am trying to do?

推荐答案

它不会有所作为，返回值是进入东西是一个对象，因为的返回值的类型必须首先确定的

It doesn't make a difference that the return value is going into something that is an object, because the type of the return value has to be determined first.

铸两个值（ DBNull.Value ， myObject.DateCreated ）为基其他，你会没事的。在这种情况下，碱可以甚至是物体

Cast one of the two values (DBNull.Value, myObject.DateCreated) to a base of the other and you 'll be fine. In this case, the base can even be object.

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