The Problem of WriteXml

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I test the XmlWrite/XmlRead from MemoryStrem, my codes is:

DataSet ds = Will.DM.ExecuteDataset("Select * from Customer);
MemoryStream msOri = new MemoryStream();
ds.WriteXml(msOri);

DataSet ds2 = new DataSet();
ds2.ReadXml(msOri);

It compiled ok, but when it run fail at the last line: ds.WriteXml(msOri);
Ther error message is
System.Xml.XmlException: Root element is missing.

The msOri is write form ds, why it can't read to ds2?

[Nicholas Paldino [.NET/C# MVP]]

The reason is because the pointer in the stream is at the end of the
stream.

You need to reset the position to the beginning of the stream. Before
the call to ReadXml, do this:

// Set the position in the stream to the beginning.
msOri.Position = 0;

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"ad" <fl****@wfes.tcc.edu.tw> wrote in message
news:Od*************@TK2MSFTNGP12.phx.gbl...

I test the XmlWrite/XmlRead from MemoryStrem, my codes is:

DataSet ds = Will.DM.ExecuteDataset("Select * from Customer);
MemoryStream msOri = new MemoryStream();
ds.WriteXml(msOri);

DataSet ds2 = new DataSet();
ds2.ReadXml(msOri);

It compiled ok, but when it run fail at the last line:
ds.WriteXml(msOri);
Ther error message is
System.Xml.XmlException: Root element is missing.

The msOri is write form ds, why it can't read to ds2?

[VJ]

ds.WriteXml(msOri, XmlWriteMode.WriteSchema);

Schema.. has to be saved.. if you want to read back to a DataSet...

"ad" <fl****@wfes.tcc.edu.tw> wrote in message
news:Od*************@TK2MSFTNGP12.phx.gbl...

I test the XmlWrite/XmlRead from MemoryStrem, my codes is:

DataSet ds = Will.DM.ExecuteDataset("Select * from Customer);
MemoryStream msOri = new MemoryStream();
ds.WriteXml(msOri);
DataSet ds2 = new DataSet();
ds2.ReadXml(msOri);

It compiled ok, but when it run fail at the last line:
ds.WriteXml(msOri);
Ther error message is
System.Xml.XmlException: Root element is missing.

The msOri is write form ds, why it can't read to ds2?

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Thanks, You give me a great help!
"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard.caspershouse.com> ¼¶¼g©ó¶l¥ó·s»D:Oz**************@TK2MSFTNGP09.phx.g bl...

The reason is because the pointer in the stream is at the end of the
stream.

You need to reset the position to the beginning of the stream. Before
the call to ReadXml, do this:

// Set the position in the stream to the beginning.
msOri.Position = 0;

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"ad" <fl****@wfes.tcc.edu.tw> wrote in message
news:Od*************@TK2MSFTNGP12.phx.gbl...

I test the XmlWrite/XmlRead from MemoryStrem, my codes is:

DataSet ds = Will.DM.ExecuteDataset("Select * from Customer);
MemoryStream msOri = new MemoryStream();
ds.WriteXml(msOri);

DataSet ds2 = new DataSet();
ds2.ReadXml(msOri);

It compiled ok, but when it run fail at the last line:
ds.WriteXml(msOri);
Ther error message is
System.Xml.XmlException: Root element is missing.

The msOri is write form ds, why it can't read to ds2?