XMLTextWriter Encoding problem

[Adam Rothberg]

The following code sample should produce a valid xml file to the
console. However, when I try this in C# (Visual Studio 2003, 1.1
Framework), there is an extra questionmark preceding the rest of the
content.

MemoryStream ms = new MemoryStream();
XmlTextWriter xtw = new XmlTextWriter(m s, Encoding.UTF8);
xtw.Namespaces = false;
xtw.Indentation = 5;
xtw.Formatting = Formatting.Inde nted;
xtw.WriteStartD ocument();
xtw.WriteStartE lement("root");
xtw.WriteStartE lement("People" );
xtw.WriteStartE lement("Person" );
xtw.WriteAttrib uteString("Firs tName", "John");
xtw.WriteAttrib uteString("Last Name", "Smith");
xtw.WriteEndEle ment();
xtw.WriteStartE lement("Person" );
xtw.WriteAttrib uteString("Firs tName", "Jane");
xtw.WriteAttrib uteString("Last Name", "Smith");
xtw.WriteEndEle ment();
xtw.WriteEndEle ment();
xtw.WriteEndEle ment();
xtw.WriteEndDoc ument();
xtw.Flush();
xtw.Close();

Console.WriteLi ne( Encoding.UTF8.G etString( ms.ToArray()));

Everything works as expected when I use ASCII encoding. Any encoding
works when I write to a file instead of a memory stream.

Anyone have the answer to this problem?

Thanks in advance.

[Kevin Yu [MSFT]]

RE: XMLTextWriter Encoding problem

Hi Adam,

The first three bytes in the byte array are BOM(Byte Order Mark 0xEFBBBF),
allowing applications to easily detect UTF-8 encoded text. If you want to
create UTF-8 encoded content without BOM, don't use the default instance
available through Encoding.UTF8, but create a new instance:

Encoding utf8 = new UTF8Encoding(fa lse);

In you program, you can do like the following:

XmlTextWriter xtw = new XmlTextWriter(m s, new UTF8Encoding(fa lse));

If anything is unclear, please feel free to reply to the post.

Kevin Yu
=======
"This posting is provided "AS IS" with no warranties, and confers no
rights."

[Adam Rothberg]

Re: XMLTextWriter Encoding problem

Thank you. That worked great.


v-kevy@online.mic rosoft.com (Kevin Yu [MSFT]) wrote in message news:<uHl4PnTxD HA.3660@cpmsftn gxa07.phx.gbl>. ..[color=blue]
> Hi Adam,
>
> The first three bytes in the byte array are BOM(Byte Order Mark 0xEFBBBF),
> allowing applications to easily detect UTF-8 encoded text. If you want to
> create UTF-8 encoded content without BOM, don't use the default instance
> available through Encoding.UTF8, but create a new instance:
>
> Encoding utf8 = new UTF8Encoding(fa lse);
>
> In you program, you can do like the following:
>
> XmlTextWriter xtw = new XmlTextWriter(m s, new UTF8Encoding(fa lse));
>
> If anything is unclear, please feel free to reply to the post.
>
> Kevin Yu
> =======
> "This posting is provided "AS IS" with no warranties, and confers no
> rights."[/color]

[Christoph Schittko [MVP]]

Re: XMLTextWriter Encoding problem

Kevin,

could you explain what the problem is with using the default instance?

Thanks,
Christoph Schittko [MVP, XmlInsider]
Software Architect, .NET Mentor

"Kevin Yu [MSFT]" <v-kevy@online.mic rosoft.com> wrote in message
news:uHl4PnTxDH A.3660@cpmsftng xa07.phx.gbl...[color=blue]
> Hi Adam,
>
> The first three bytes in the byte array are BOM(Byte Order Mark 0xEFBBBF),
> allowing applications to easily detect UTF-8 encoded text. If you want to
> create UTF-8 encoded content without BOM, don't use the default instance
> available through Encoding.UTF8, but create a new instance:
>
> Encoding utf8 = new UTF8Encoding(fa lse);
>
> In you program, you can do like the following:
>
> XmlTextWriter xtw = new XmlTextWriter(m s, new UTF8Encoding(fa lse));
>
> If anything is unclear, please feel free to reply to the post.
>
> Kevin Yu
> =======
> "This posting is provided "AS IS" with no warranties, and confers no
> rights."
>[/color]

[Kevin Yu [MSFT]]

Re: XMLTextWriter Encoding problem

Hi Christoph,

The UTF8 is a static instance of UTF8Encoding class. The encoder using this
instance will emit an UTF8 identifier, which is the 3 bytes I mentioned in
my last post. The identifer will help the program to recognize the UTF8
encoding. If we create a new instance with the first parameter of the
constructor set to false, it will not be emited.

Kevin Yu
=======
"This posting is provided "AS IS" with no warranties, and confers no
rights."

[Christoph Schittko [MVP]]

Re: XMLTextWriter Encoding problem

Thanks :)

--
HTH
Christoph Schittko [MVP]
Software Architect, .NET Mentor
"Kevin Yu [MSFT]" <v-kevy@online.mic rosoft.com> wrote in message
news:V0VruNhxDH A.2604@cpmsftng xa07.phx.gbl...[color=blue]
> Hi Christoph,
>
> The UTF8 is a static instance of UTF8Encoding class. The encoder using[/color]
this[color=blue]
> instance will emit an UTF8 identifier, which is the 3 bytes I mentioned in
> my last post. The identifer will help the program to recognize the UTF8
> encoding. If we create a new instance with the first parameter of the
> constructor set to false, it will not be emited.
>
> Kevin Yu
> =======
> "This posting is provided "AS IS" with no warranties, and confers no
> rights."
>[/color]