我正在使用下面的查询
foreach (var callDetailsForNode_ReArrange in callDetailsForNodes_ReArrange)
{
var test = from r1 in dtRowForNode.AsEnumerable()
join r2 in dtFileRowForNode.AsEnumerable()
on r1.Field<int>("Lng_Upload_Id") equals r2.Field<int>("Lng_Upload_Id")
where ((r1.Field<string>("Txt_Called_Number") == callDetailsForNode_ReArrange.caller2.ToString()) || r1.Field<string>("Txt_Calling_Number") == callDetailsForNode_ReArrange.caller2.ToString())
select r2.Field<string>("Txt_File_Name");
var d = test.Distinct();
}
到目前为止,这个查询运行得非常快。但是当我添加了
时:string[] str =d.ToArray();
strFileName = string.Join(",", str);
运行需要差不多4-5秒钟。是什么原因让添加.ToArray()
这么慢?