问插入带有编码SHIFT-JIS错误的XML文件

EN

<?xml version="1.0" encoding="SHIFT-JIS" standalone="yes"?>
<海外管理ファイル><PO番号>GV05097</PO番号><データベース><PO><Tbl_PO_H PO番号="GV05097"><DATA><PO番号 TYPE="200" LENGTH="13">GV05097</PO番号></DATA></Tbl_PO_H></PO></データベース></海外管理ファイル>

alter PROCEDURE [dbo].[proc_TBL_PO_H_LoadXMLPO]
@xml  XML
AS  
    BEGIN
        SET NOCOUNT ON;
        INSERT INTO [ENVIETNAMPO].[dbo].[TBL_PO_H]
              SELECT
                  TBL_PO_H.value('(PO番号/text())[1]','varchar(13)') AS PO番号, --TAG
                  TBL_PO_H.value('(PO発行日/text())[1]','varchar(10)') AS PO発行日                  
              FROM
                 @xml.nodes('/海外管理ファイル/データベース/PO/Tbl_PO_H/DATA')AS TEMPTABLE(TBL_PO_H)      
    END

string pathUser = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
            string pathDesktop = Path.Combine(pathUser, "Desktop");
            var xmlfilename = string.Empty;
            var xmlfilePath = string.Empty;
            //var dt = new DataTable();           
            var sqlConn = new SqlConnection(strConStr);
            try
            {
                    openFileDialog1.InitialDirectory = @pathDesktop;
                    openFileDialog1.Title = "Browse XML PO File";
                    openFileDialog1.Filter = "XML files (*.xml)|*.xml|All files (*.*)|*.*";
                    openFileDialog1.CheckFileExists = true;
                    openFileDialog1.CheckPathExists = true;
                    openFileDialog1.ShowHelp = true;
                    openFileDialog1.FileName = "*.xml";
                if (openFileDialog1.ShowDialog() == DialogResult.OK)
                {
                    xmlfilename =openFileDialog1.SafeFileName;
                    xmlfilePath = pathDesktop +"\\"+ xmlfilename;
                    string xml = File.ReadAllText(xmlfilePath, Encoding.GetEncoding("SHIFT-JIS"));
                    sqlConn.Open();

                    var cmd = new SqlCommand("proc_TBL_PO_H_LoadXMLPO", sqlConn);
                    cmd.CommandType = CommandType.StoredProcedure;
                    cmd.Parameters.AddWithValue("@xml", xml);
                    SqlCommand arithabortCommand = new SqlCommand("SET ARITHABORT ON", sqlConn);
                    arithabortCommand.ExecuteNonQuery();  
                    cmd.ExecuteNonQuery(); 
                    sqlConn.Close();
                }

                    MessageBox.Show("PO XML File has been imported successfully.", "Information",
                    MessageBoxButtons.OK,
                    MessageBoxIcon.Information);
            }
            catch (Exception ex)
            {

                MessageBox.Show(ex.ToString());
            }

System.Data.SqlClient.SqlException 0x80131904: parsing XML Line 1, character 59. Cannot swicth I- code ....