在C＃中检查多个值的条件运算符 [英] Conditional operator for more than 1 values checking in C#

问题描述

你能帮我解决一下如何检查多个值来检查c＃lamda表达式

Could you please help me that how to check more than 1 values to check in c# lamda expression

DocumentationLink = context.APIDocumentationTypes.Where(x => x.DocumentationTypeId == a.DocumentationTypeId).Select(x => x.DocumentationDescription).FirstOrDefault().ToLower() != "value1" ? a.DocumentationLink : "",

i需要查看

i need to check with

value1

和

value2

在同一行。



我尝试了什么：

in same line.

What I have tried:

<pre>DocumentationLink = context.APIDocumentationTypes.Where(x => x.DocumentationTypeId == a.DocumentationTypeId).Select(x => x.DocumentationDescription).FirstOrDefault().ToLower() != "value1" && "value2"? a.DocumentationLink : "",

推荐答案

尝试：

Try:

string result = context.APIDocumentationTypes.Where(x => x.DocumentationTypeId == a.DocumentationTypeId)
                                             .Select(x => x.DocumentationDescription)
                                             .FirstOrDefault().ToLower();
DocumentAtionLink = ( result != "value1" && result != "value2") ? a.DocumentationLink : "";

但请注意如果没有符合选择的元素，则FirstOrDefault 将返回 null - at你的 ToLower 调用将导致 NullReferenceException 。

But do note that FirstOrDefault will return null if there are no elements that matched your Select - at which point your ToLower call will cause a NullReferenceException.

这是一个< b> 猜测 你可能需要做什么：

Here's a guess at what you might need to do:

private DocumentationLink getadl(AContext ctx, APIDocumentationTypes a)
{
    var adl = ctx.APIDocumentationTypes.Where(x => x.DocumentationTypeId == a.DocumentationTypeId)

        .Select(x => x.DocumentationDescription.ToLower())

        .FirstOrDefault(
            descr => !(descr == "value1" || descr == "value2")
    );

    // what is the default Type here if no match is found ?
    return (adl == "") ? null : a.DocumentationLink;
}

当然，你可以在'选择查询中创建中间变量，如有必要/

Of course, you can create "intermediate" variables in a 'Select query, if necessary/

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