能实现？ string name=dataSet.ReadXml(new System.IO.MemoryStream(System.Text.Encoding.Default.GetBytes(xmlStr)));  就可以？  那取出节点里不重复的该怎么做勒，能帮我写全点吗 ？

 我是新手  怎么操作啊 ？

var str = @"<?xml version='1.0' encoding='utf-16'?>
            <ArrayOfSpecialtyEntity xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xsd='http://www.w3.org/2001/XMLSchema'>
                <SpecialtyEntity>
                <LoginNameList>HQCEC\h2255cjh</LoginNameList>
                <Name>文件管理</Name>
                <NameList>陈景花</NameList>
                </SpecialtyEntity>
                <SpecialtyEntity>
                <LoginNameList>HQCEC\h4587wjh</LoginNameList>
                <Name>文件管理</Name>
                <NameList>王静湖</NameList>
                </SpecialtyEntity
                <SpecialtyEntity>
                <LoginNameList>HQCEC\h4587wjh</LoginNameList>
                <Name>test</Name>
                <NameList>王静湖</NameList>
                </SpecialtyEntity>
            </ArrayOfSpecialtyEntity>";
var match = System.Text.RegularExpressions.Regex.Matches(str, @"<Name>(\w+)</Name>");
var list = new List<string>();
foreach (System.Text.RegularExpressions.Match item in match)
{
    var name = item.Value.Replace("<Name>", "").Replace("</Name>", "");
    if (!list.Contains(name))
    {
        list.Add(name);
    }
}

@Rich.T: 谢谢，我测试过 这样能取出来   那请问 我是要取出不重复的具体该怎么做啊 ？ 最后还是字符串格式   比如 上面的   最后成为  “文件管理，test”

@miloss: 

现在这个给你取出来的就是不重复的呀