如何在C#中使用LINQ更新单个liLi对象 [英] How to update a single item of liist of objects using LINQ in C#

问题描述

我想更新具有属性Text="ALL"的列表的Value.

I want like to update the Value of the list which hast property Text="ALL".

public class Season
    {
      public string Text {get;set;}
      public string Value {get;set;}
      public bool ValueSelected {get;set;}
    }

推荐答案

LINQ中的"Q"代表查询". LINQ并不是要更新对象.

The 'Q' in LINQ stands for "Query". LINQ is not meant to update objects.

您可以使用LINQ查找要更新的对象，然后传统地"更新它.

You can use LINQ to find the object you want to update and then update it "traditionally".

var toUpdate = _seasons.Single(x => x.Text == "ALL");

toUpdate.ValueSelected = true;

此代码假定Text == "ALL"恰好有一个一个条目.如果不存在或存在多个，则此代码将引发异常.

This code assumes that there is exactly one entry with Text == "ALL". This code will throw an exception if there is none or if there are multiple.

如果不存在或不存在，请使用SingleOrDefault:

If there is either none or one, use SingleOrDefault:

var toUpdate = _seasons.SingleOrDefault(x => x.Text == "ALL");

if(toUpdate != null)
    toUpdate.ValueSelected = true;

如果可能有多个，请使用Where:

If it's possible that there are multiple, use Where:

var toUpdate = _seasons.Where(x => x.Text == "ALL");

foreach(var item in toUpdate)
    item.ValueSelected = true;

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