var query = from y in (from x in DataTable.Cast<DataRow>()
                       select new { a = x["列1"].ToString(), b = x["列2"].ToString() })
            group y by y.a into g
            select new { key = g.Key, values = g.Select(z => z.b).ToArray() };
foreach (var item in query)
{
    string name = item.key;
    string[] values = item.values;
    ...//你可以处理，已经归类放入数组了
}

------解决方案--------------------
探讨


天哪 什么时候能够我楼上的代码 总是那种似懂非懂的感觉


------解决方案--------------------
dim list as new dictionary(of string,list(of string))

循环数据库数据
if list.ContainsKey("列1") then
list("列1").add("列2")
else
list("列1")=new list(of string)
list("列1").add("列2")
end

------解决方案--------------------
如果你要转换成字典，用linq还是一行。
C# code
var query = from y in (from x in DataTable.Cast<DataRow>()
                       select new { a = x["列1"].ToString(), b = x["列2"].ToString() })
            group y by y.a into g
            select new { key = g.Key, values = g.Select(z => z.b).ToArray() };
Dictionary<string, List<string>> list = query.ToDictionary(x => x.key, x => x.values.ToList());

------解决方案--------------------
探讨


感觉 rayyu1989 的代码很精悍哦。

不知道是否可以。

dim list as new dictionary(of string,list(of string))
是下面这个意思吗？？
dictionary<string s,list> list = new dictionary<string s,list>();


------解决方案--------------------
 var source = from temp in dt.AsEnumerable()
                        group temp by temp.Field<string>("列1") into g
                        select new
                            {
                                key = g.Key,
                                g,
                                values = g.Select(t => t.Field<string>("列2")).ToArray()
                            };
          foreach (var t in source)
          {
                              string[] str=  t.values;
          }