以下三种方案的实质应该都是序列化的，有一位大神说过“跨进程的不序列化应该去面壁！”O(∩_∩)O哈哈哈~

解决方案一：返回dataset

WebService中的方法代码如下：
 
    [WebMethod]
    public DataSet GetDataSet()
    {
        DataTable dt=new DataTable("mytable");
        DataColumn dc=new DataColumn("id",typeof(string));
        dt.Columns.Add(dc);
        DataRow dr=dt.NewRow();
        dr["id"]="1111111";
        dt.Rows.Add(dr);
        DataSet ds=new DataSet();
        ds.Tables.Add(dt);
        return ds;
    }
 
 
 
在调用客户端直接使用DataSet
 
        DataSet ds = db.GetDataSet();//db是服务代理类实例
        GridView1.DataSource = ds.Tables[0];
        GridView1.DataBind();

解决方案二：给返回的datatable命名

    webservice文件中

         [WebMethod]
         public DataTable dt()
         {
             DataTable dt = new DataTable("default");
             dt.Columns.Add("id");
             dt.Columns.Add("name");
             for (int i = 0; i < 10; i++)
             {
                 DataRow dr = dt.NewRow();
                 dr["id"] = i.ToString();
                 dr["name"] = "name" + i.ToString();
                 dt.Rows.Add(dr);
             }
             return dt;
         }

        调用页面中

             WebService1.WebService1 service = new WebService1.WebService1();
             DataTable dt = service.dt();
             gvUser.DataSource = dt;
             gvUser.DataBind();

       最关键的是在webservice的方法中为datatable命名,否则就会报错.

解决方案三：服务中将DataTable的序列化成xml字符串，调用时候在反序列化成DataTable

#region DataTable序列化和反序列化         /// <summary>         /// DataTableToXML         /// </summary>         public static string ConvertDataTableToXML(DataTable dt)         {             return ConvertDataTableToXML(dt,string.Empty);         }         public static string ConvertDataTableToXML(DataTable dt,string aaa)         {             StringWriter sw = null;             try             {                 if (dt.TableName == string.Empty)                     dt.TableName = "table1";                 sw = new StringWriter();                 dt.WriteXml(sw,XmlWriteMode.WriteSchema);                 return sw.ToString();             }             catch (System.Exception ex)             {                 throw ex;             }             finally             {                 if (sw != null)                     sw.Close();             }         }         /// <summary>         /// XMLToDataTable         /// </summary>         public static DataTable ConvertXMLToDataTable(string xmlData)         {             TextReader sr = null;             try             {                 DataTable dt = new DataTable();                 sr = new StringReader(xmlData);                 dt.ReadXml(sr);                 return dt;             }             catch (System.Exception ex)             {                 throw ex;             }             finally             {                 if (sr != null) sr.Close();             }         }         #endregion