Reading XML into Datatable gives incorrect DateTime when the time has Time Zone info

问题

So my client runs some code that writes their current time to an xml file which I then want to read back into a data table but I am getting incorrect time information.

For example their current time is 09:31 their time zone is UTC+1:00.

my code is:

var ds = new DataSet("MyDataSet");
var dt = ds.Tables.Add("MyDataTable");
dt.Columns.Add("MyDateTime", typeof(DateTime));

var startingDateTime = DateTime.Now;
dt.Rows.Add(startingDateTime);
String xmlDT = String.Empty;

using (MemoryStream memoryStream = new MemoryStream())
{
    dt.WriteXml(memoryStream,XmlWriteMode.WriteSchema);
    xmlDT = Encoding.UTF8.GetString(memoryStream.ToArray());
}
string myFile = @"C:\Users\me\Documents\test1.txt"
XmlDocument doc = new XmlDocument();
doc.LoadXml(xmlDT);
doc.Save(myFile);

myFile now contains:

<NewDataSet>
  <xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
    <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:MainDataTable="MyDataTable" msdata:UseCurrentLocale="true">
      <xs:complexType>
        <xs:choice minOccurs="0" maxOccurs="unbounded">
          <xs:element name="MyDataTable">
            <xs:complexType>
              <xs:sequence>
                <xs:element name="MyDateTime" type="xs:dateTime" minOccurs="0" />
              </xs:sequence>
            </xs:complexType>
          </xs:element>
        </xs:choice>
      </xs:complexType>
    </xs:element>
  </xs:schema>
  <MyDataTable>
    <MyDateTime>2015-02-12T09:31:37.4250365+01:00</MyDateTime>
  </MyDataTable>
</NewDataSet>

This file is then sent to my server in the UK (+00:00) where I then read the file using:

DataTable datatable2 = new DataTable();
datatable2.ReadXml(myFile);

and my datatable now contains 1 row that has a datetime of 08:30 but this is incorrect and I would like it to store the clients time. How would I do this with a change to either my client or server code?

回答1:

so client side you can add the line:

dt.Columns[0].DateTimeMode = DataSetDateTime.Unspecified;

or as a more generic method:

public static void RemoveTimezoneForDataSet(DataSet ds)
{
    foreach (DataTable dt in ds.Tables)
    {
        foreach (DataColumn dc in dt.Columns)
        {

            if (dc.DataType == typeof(DateTime))
            {
                dc.DateTimeMode = DataSetDateTime.Unspecified;
            }
        }
    }
}

this saves the XML as:

<NewDataSet>
  <xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
    <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:MainDataTable="MyDataTable" msdata:UseCurrentLocale="true">
      <xs:complexType>
        <xs:choice minOccurs="0" maxOccurs="unbounded">
          <xs:element name="MyDataTable">
            <xs:complexType>
              <xs:sequence>
                <xs:element name="MyDateTime" msdata:DateTimeMode="Unspecified" type="xs:dateTime" minOccurs="0" />
              </xs:sequence>
            </xs:complexType>
          </xs:element>
        </xs:choice>
      </xs:complexType>
    </xs:element>
  </xs:schema>
  <MyDataTable>
    <MyDateTime>2015-02-12T09:13:39.8180356</MyDateTime>
  </MyDataTable>
</NewDataSet>

So the time gets serialized correctly on the server

回答2:

I suggest simply changing the type of the MyDateTime column to string.

Strings like 2015-02-12T09:31:37.4250365+01:00 can then easily parsed into a DateTimeOffset, which makes handling dates of different timezones easier.

// note I changed +01:00 to +05:00 since I'm in de-DE (+01:00)
// to illustrate the difference
var offset = DateTimeOffset.Parse("2015-02-12T09:31:37.4250365+05:00");

//prints '12.02.2015 09:31:37' (the "original" date)
Console.WriteLine(offset.DateTime);      

//prints '12.02.2015 05:31:37 +01:00' (converted to local time)
Console.WriteLine(offset.ToLocalTime());

来源：https://stackoverflow.com/questions/28472824/reading-xml-into-datatable-gives-incorrect-datetime-when-the-time-has-time-zone

标签

xml

datetime

timezone