c# - 连接项目列表中的属性

Question

我在处理一小段代码时遇到了问题。

我有一个 MapItem 类的列表，其中包含几个属性 Address 和 Html，我需要将每个项目的 Html 属性与相同的 Address 属性连接起来例如:

firstMapItem = new MapItem { Address = "1122 Elm Street", 
                             Html="<p>some html</p>" };  
secondMapItem = new MapItem { Address = "1122 Elm Street", 
                              Html="<p>different html</p>" };

会变成:

firstMapItem.Address == "1122 Elm Street";
firstMapItem.Html == "<p>some html</p><p>different html</p>";

secondMapItem.Address == "1122 Elm Street"; 
secondMapItem.Html == "<p>some html</p><p>different html</p>";

这是我目前尝试过的:

            foreach (MapItem item in mapItems)
            {
                var sameAddress = from m in mapItems
                                  where m.Address == item.Address
                                  select m;

                if (sameAddress.Count() > 1)
                {
                    //tried inserting -> item.Html = ""; right here as well
                    foreach (MapItem single in sameAddress)
                    {
                        item.Html += single.Html;
                    }
                }
            }

我可能把它变得比需要的更复杂了。

提前致谢。

Answer 1

您可以按 Address 分组，然后连接 Html 值:

var results = from m in mapItems
              group m by m.Address into ms
              select new MapItem
              {
                  Address = ms.Key,
                  Html = string.Concat(ms.Select(m => m.Html))
              };