使用lambda连接对象的字符串属性

Question

请考虑以下事项：

public class MyObject
{
   public bool B;
   public string Txt;
}

List<MyObject> list; //list of a bunch of MyObject's 

使用lambda表达式，如何生成由这些对象的Txt的逗号分隔值组成的字符串，其中B为真？

谢谢。

Answer 1

for .net 3.5：

string.Join(",", list.Where(o => o.B).Select(o => o.Txt).ToArray())

for .net 4.0：

string.Join(",", list.Where(o => o.B).Select(o => o.Txt))

Answer 2

string myString = string.Join(",", list.Where(x => x.B).Select(x=>x.Txt));

Answer 3

var strFinal = "";
myList.ForEach(pq => strFinal += ", " + pq.ItemId);