C＃表达式if语句，可能扩展吗？ [英] C# Expressional if statements, possible expansion?

问题描述

大家好，我的问题是：如何直接执行一个函数或委托以及如何使用C＃中的单个表达式返回语句从方法返回值

Hi guys i have a question which is : how to directly execute a function or delegate as well as returning a value from a method using one single Expressional return statement in C#

* For参考，我正在使用C＃7

*For reference, I am using C#7

在这种情况下，我需要向用户返回一个已生成的对象，如下所示：

In this context I need to return to the user an Object which has been generated like this:

object obj = cmd.ExecuteScalar();

我还有一个日志记录功能，我想调用它：

I also have a logging function which I want to call:

DoLog(cmd.CommandText)

PS：我100％意识到，我可以使用一些if语句更简单的方式来无条件地实现此目标-我只是问是否有人可以为我提供最优雅的解决方案一个衬里

PS: I am 100% aware that I can achieve this non-conditionally using a couple of if statements in a much easier way - i'm simply asking if anyone can provide me with the most elegant "one liner" approach possible.

以下是条件返回表达式通常如何工作的标准示例

Here is a standard example of how conditional return expressions usually work

return (someBool)
   ? value1
   : value2;

如果someBool为TRUE，这将返回'value1'；

this will return 'value1' if someBool is TRUE;

基本上我的问题是我可以做这样的事情

Basically my question is can i do something like this

return (chkStatus)
    ? (obj & DoLog(cmd.CommandText))
    : null;

为了回应一些建议我可以使用单个管道运算符分割收益，而您的建议是真诚的，我想您从未尝试过编译它们。

In response to some of you who have suggested that I can use a single pipe operator to split the return, while your suggestions are in good faith, I assume you never tried to compile them

可以作为类型：Object和Void无法直接比较，从而导致编译时错误。

If you had you would see that it doesn't work as the types: Object and Void are NOT directly comparable thus causing a compile time error.

我对更精致/更优雅的方法的要求仍然存在。

My request for a more refined / elegant method still stands.

推荐答案

您可以使用lambda来解决问题，但这并不是一个干净的语法：

You can work something out using lambda's, but it will not be a clean syntax:

        return (chkStatus 
            ? (Func<object>)(() => { 
                  DoLog(cmd.CommandText); 
                  return obj; 
              })
            : () => null)();

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