使用LINQ，我怎么找到从列表中给定的属性值的对象？ [英] Using LINQ, how do I find an object with a given property value from a List?

问题描述

我有一个名为问题类。这问题具有属性 QuestionID 和问题答案。同时通过提问中的foreach这个 list进行遍历，我一定要找到 .QuestionID = 12 。如果我发现 .QuestionID = 12 那么我得马上值分配给 .QuestionAnswer =SomeText则会的 .QuestionID = 14 。

我不想再重复在 .QuestionId = 12'找到 .QuestionID =再次14`。

有什么办法，我可以使用LINQ直接到 .QuestionID = 14 ？

例如：

 对于每个mQuestion作为问题在_mQuestions
    如果mQuestion.QuestionId = 12然后
         查找mQuestion.QuestionID = 14，并插入到Somtext
          'mQuestion.QuestionAnswer =SomeText则会
    万一
下一个
 




解决方案

我认为你在寻找这样的事情。如果我有时间，我将它翻译成VB，但我认为你可以遵循。

 如果（_mQuestions.Any（Q =＆GT; q.QuestionID == 12））
{
   问题question14 = _mQuestions.FirstOrDefault（Q =＆GT; q.QuestionID == 14）;
   如果（question14！= NULL）
       question14.QuestionAnswer =一些文本;
}
 

I have a class called Questions. This Questions has properties QuestionID and QuestionAnswer. While iterating through this List of Question in foreach, I have to find .QuestionID = 12. If I find .QuestionID = 12 then I have to immediately assign a value to .QuestionAnswer = "SomeText" of .QuestionID = 14.

I don't want iterate again inside .QuestionId = 12' to find.QuestionID = 14` again.

Is there any way I can go directly to .QuestionID = 14 using LINQ?.

For example:

For Each mQuestion As Question In _mQuestions
    If mQuestion.QuestionId = 12 Then
         'Find mQuestion.QuestionID= 14 and insert Somtext to 
          'mQuestion.QuestionAnswer="SomeText"
    End IF
Next

解决方案

I think you're looking for something like this. If I have a moment, I'll translate it to VB, but I think you can follow.

if (_mQuestions.Any(q => q.QuestionID == 12)) 
{
   Question question14 = _mQuestions.FirstOrDefault(q => q.QuestionID == 14);
   if (question14 != null)
       question14.QuestionAnswer = "Some Text";
}

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