转XML格式与DataTable、DataSet、DataView格式的转换

今天用到一个功能：就是把从数据库读出来的内容转换成XML字符串流格式，并输出给一个功能函数。
在写的过程，为方便以后的使用，我对这一功能进行分装。该类的具体格式如下：
XmlConvert类
命名空间：Nimeux.XmlConvert
XmlToData子类
函数：
1、public static DataSet CXmlToDataSet(string xmlStr)将xml字符串转换成DataSet
2、public static DataTable CXmlToDatatTable(string xmlStr, int tableIndex)；将xml字符串转换成DataTable
3、public static DataSet CXmlFileToDataSet(string xmlFilePath)将xml文件转换成DataSet
4、public static DataTable CXmlToDataTable(string xmlFilePath, int tableIndex)将xml文件转换成DataTable
DataToXml子类
函数：
1、public static string CDataToXml(DataTable dt)；
2、public static string CDataToXml(DataSet ds, int tableIndex)；
3、public static string CDataToXml(DataView dv)；
4、 public static bool CDataToXmlFile(DataTable dt, string xmlFilePath)；
5、public static bool CDataToXmlFile(DataSet ds, int tableIndex, string xmlFilePath)
以上几个功能函数主要实现把Xml字符串、文件转换成DataSet、DataTable、DataView。
源代码中，对各个功能函数都进行了标注，以供大家参考！ 

/**//// <summary>
    /// XML形式的字符串、XML文件转换成DataSet、DataTable格式
    /// 章学敏
    /// 2007-08-16
    /// </summary>
    public class XmlToData
    {
        /**//// <summary>
        /// 将Xml内容字符串转换成DataSet对象
        /// </summary>
        /// <param name="xmlStr">Xml内容字符串</param>
        /// <returns>DataSet对象</returns>
        public static DataSet CXmlStrToDataSet(string xmlStr)
        {
            if (!string.IsNullOrEmpty(xmlStr))
            {
                StringReader StrStream = null;
                XmlTextReader Xmlrdr = null;
                try
                {
                    DataSet ds = new DataSet();
                    //读取字符串中的信息
                    StrStream = new StringReader(xmlStr);
                    //获取StrStream中的数据
                    Xmlrdr = new XmlTextReader(StrStream);
                    //ds获取Xmlrdr中的数据                
                    ds.ReadXml(Xmlrdr);
                    return ds;
                }
                catch (Exception e)
                {
                    throw e;
                }
                finally
                {
                    //释放资源
                    if (Xmlrdr != null)
                    {
                        Xmlrdr.Close();
                        StrStream.Close();
                        StrStream.Dispose();
                    }
                }
            }
            else
            {
                return null;
            }
        }

        /**//// <summary>
        /// 将Xml字符串转换成DataTable对象
        /// </summary>
        /// <param name="xmlStr">Xml字符串</param>
        /// <param name="tableIndex">Table表索引</param>
        /// <returns>DataTable对象</returns>
        public static DataTable CXmlStrToDataTable(string xmlStr, int tableIndex)
        {
            return CXmlStrToDataSet(xmlStr).Tables[tableIndex];
        }

        /**//// <summary>
        /// 将Xml字符串转换成DataTable对象
        /// </summary>
        /// <param name="xmlStr">Xml字符串</param>
        /// <returns>DataTable对象</returns>
        public static DataTable CXmlStrToDataTable(string xmlStr)
        {
            return CXmlStrToDataSet(xmlStr).Tables[0];
        }

        /**//// <summary>
        /// 读取Xml文件信息,并转换成DataSet对象
        /// </summary>
        /// <remarks>
        /// DataSet ds = new DataSet();
        /// ds = CXmlFileToDataSet("/XML/upload.xml");
        /// </remarks>
        /// <param name="xmlFilePath">Xml文件地址</param>
        /// <returns>DataSet对象</returns>
        public static DataSet CXmlFileToDataSet(string xmlFilePath)
        {
            if (!string.IsNullOrEmpty(xmlFilePath))
            {
                string path = HttpContext.Current.Server.MapPath(xmlFilePath);
                StringReader StrStream = null;
                XmlTextReader Xmlrdr = null;
                try
                {
                    XmlDocument xmldoc = new XmlDocument();
                    //根据地址加载Xml文件
                    xmldoc.Load(path);

                    DataSet ds = new DataSet();
                    //读取文件中的字符流
                    StrStream = new StringReader(xmldoc.InnerXml);
                    //获取StrStream中的数据
                    Xmlrdr = new XmlTextReader(StrStream);
                    //ds获取Xmlrdr中的数据
                    ds.ReadXml(Xmlrdr);
                    return ds;
                }
                catch (Exception e)
                {
                    throw e;
                }
                finally
                {
                    //释放资源
                    if (Xmlrdr != null)
                    {
                        Xmlrdr.Close();
                        StrStream.Close();
                        StrStream.Dispose();
                    }
                }
            }
            else
            {
                return null;
            }
        }

        /**//// <summary>
        /// 读取Xml文件信息,并转换成DataTable对象
        /// </summary>
        /// <param name="xmlFilePath">xml文江路径</param>
        /// <param name="tableIndex">Table索引</param>
        /// <returns>DataTable对象</returns>
        public static DataTable CXmlFileToDataTable(string xmlFilePath, int tableIndex)
        {
            return CXmlFileToDataSet(xmlFilePath).Tables[tableIndex];
        }

        /**//// <summary>
        /// 读取Xml文件信息,并转换成DataTable对象
        /// </summary>
        /// <param name="xmlFilePath">xml文江路径</param>
        /// <returns>DataTable对象</returns>
        public static DataTable CXmlFileToDataTable(string xmlFilePath)
        {
            return CXmlFileToDataSet(xmlFilePath).Tables[0];
        }
    }

/**//// <summary>
    /// 把DataSet、DataTable、DataView格式转换成XML字符串、XML文件
    /// 章学敏
    /// 2007-08-16
    /// </summary>
    public class DataToXml
    {
        /**//// <summary>
        /// 将DataTable对象转换成XML字符串
        /// </summary>
        /// <param name="dt">DataTable对象</param>
        /// <returns>XML字符串</returns>
        public static string CDataToXml(DataTable dt)
        {
            if (dt != null)
            {
                MemoryStream ms = null;
                XmlTextWriter XmlWt = null;
                try
                {
                    ms = new MemoryStream();
                    //根据ms实例化XmlWt
                    XmlWt = new XmlTextWriter(ms, Encoding.Unicode);
                    //获取ds中的数据
                    dt.WriteXml(XmlWt);
                    int count = (int)ms.Length;
                    byte[] temp = new byte[count];
                    ms.Seek(0, SeekOrigin.Begin);
                    ms.Read(temp, 0, count);
                    //返回Unicode编码的文本
                    UnicodeEncoding ucode = new UnicodeEncoding();
                    string returnValue = ucode.GetString(temp).Trim();
                    return returnValue;
                }
                catch (System.Exception ex)
                {
                    throw ex;
                }
                finally
                {
                    //释放资源
                    if (XmlWt != null)
                    {
                        XmlWt.Close();
                        ms.Close();
                        ms.Dispose();
                    }
                }
            }
            else
            {
                return "";
            }
        }

        /**//// <summary>
        /// 将DataSet对象中指定的Table转换成XML字符串
        /// </summary>
        /// <param name="ds">DataSet对象</param>
        /// <param name="tableIndex">DataSet对象中的Table索引</param>
        /// <returns>XML字符串</returns>
        public static string CDataToXml(DataSet ds, int tableIndex)
        {
            if (tableIndex != -1)
            {
                return CDataToXml(ds.Tables[tableIndex]);
            }
            else
            {
                return CDataToXml(ds.Tables[0]);
            }
        }

        /**//// <summary>
        /// 将DataSet对象转换成XML字符串
        /// </summary>
        /// <param name="ds">DataSet对象</param>
        /// <returns>XML字符串</returns>
        public static string CDataToXml(DataSet ds)
        {
            return CDataToXml(ds, -1);
        }

        /**//// <summary>
        /// 将DataView对象转换成XML字符串
        /// </summary>
        /// <param name="dv">DataView对象</param>
        /// <returns>XML字符串</returns>
        public static string CDataToXml(DataView dv)
        {
            return CDataToXml(dv.Table);
        }
        
        /**//// <summary>
        /// 将DataSet对象数据保存为XML文件
        /// </summary>
        /// <param name="dt">DataSet</param>
        /// <param name="xmlFilePath">XML文件路径</param>
        /// <returns>bool值</returns>
        public static bool CDataToXmlFile(DataTable dt, string xmlFilePath)
        {
            if ((dt != null) && (!string.IsNullOrEmpty(xmlFilePath)))
            {
                string path = HttpContext.Current.Server.MapPath(xmlFilePath);
                MemoryStream ms = null;
                XmlTextWriter XmlWt = null;
                try
                {
                    ms = new MemoryStream();
                    //根据ms实例化XmlWt
                    XmlWt = new XmlTextWriter(ms, Encoding.Unicode);
                    //获取ds中的数据
                    dt.WriteXml(XmlWt);
                    int count = (int)ms.Length;
                    byte[] temp = new byte[count];
                    ms.Seek(0, SeekOrigin.Begin);
                    ms.Read(temp, 0, count);
                    //返回Unicode编码的文本
                    UnicodeEncoding ucode = new UnicodeEncoding();
                    //写文件
                    StreamWriter sw = new StreamWriter(path);
                    sw.WriteLine("<?xml version=\"1.0\" encoding=\"utf-8\"?>");
                    sw.WriteLine(ucode.GetString(temp).Trim());
                    sw.Close();
                    return true;
                }
                catch (System.Exception ex)
                {
                    throw ex;
                }
                finally
                {
                    //释放资源
                    if (XmlWt != null)
                    {
                        XmlWt.Close();
                        ms.Close();
                        ms.Dispose();
                    }
                }
            }
            else
            {
                return false;
            }
        }

        /**//// <summary>
        /// 将DataSet对象中指定的Table转换成XML文件
        /// </summary>
        /// <param name="ds">DataSet对象</param>
        /// <param name="tableIndex">DataSet对象中的Table索引</param>
        /// <param name="xmlFilePath">xml文件路径</param>
        /// <returns>bool]值</returns>
        public static bool CDataToXmlFile(DataSet ds, int tableIndex, string xmlFilePath)
        {
            if (tableIndex != -1)
            {
                return CDataToXmlFile(ds.Tables[tableIndex], xmlFilePath);
            }
            else
            {
                return CDataToXmlFile(ds.Tables[0], xmlFilePath);
            }
        }

        /**//// <summary>
        /// 将DataSet对象转换成XML文件
        /// </summary>
        /// <param name="ds">DataSet对象</param>
        /// <param name="xmlFilePath">xml文件路径</param>
        /// <returns>bool]值</returns>
        public static bool CDataToXmlFile(DataSet ds, string xmlFilePath)
        {
            return CDataToXmlFile(ds, -1, xmlFilePath);
        }

        /**//// <summary>
        /// 将DataView对象转换成XML文件
        /// </summary>
        /// <param name="dv">DataView对象</param>
        /// <param name="xmlFilePath">xml文件路径</param>
        /// <returns>bool]值</returns>
        public static bool CDataToXmlFile(DataView dv, string xmlFilePath)
        {
            return CDataToXmlFile(dv.Table, xmlFilePath);
        }
    }