Write text files without Byte Order Mark (BOM)?
vb.netEncodingFile HandlingByte Order-Markvb.net Problem Overview
I am trying to create a text file using VB.Net with UTF8 encoding, without BOM. Can anybody help me, how to do this?
I can write file with UTF8 encoding but, how to remove Byte Order Mark from it?
edit1: I have tried code like this;
Dim utf8 As New UTF8Encoding()
Dim utf8EmitBOM As New UTF8Encoding(True)
Dim strW As New StreamWriter("c:\temp\bom\1.html", True, utf8EmitBOM)
strW.Write(utf8EmitBOM.GetPreamble())
strW.WriteLine("hi there")
strW.Close()
Dim strw2 As New StreamWriter("c:\temp\bom\2.html", True, utf8)
strw2.Write(utf8.GetPreamble())
strw2.WriteLine("hi there")
strw2.Close()
1.html get created with UTF8 encoding only and 2.html get created with ANSI encoding format.
Simplified approach - http://whatilearnttuday.blogspot.com/2011/10/write-text-files-without-byte-order.html
vb.net Solutions
Solution 1 - vb.net
In order to omit the byte order mark (BOM), your stream must use an instance of UTF8Encoding
other than System.Text.Encoding.UTF8
(which is configured to generate a BOM). There are two easy ways to do this:
1. Explicitly specifying a suitable encoding:
-
Call the
UTF8Encoding
constructor withFalse
for theencoderShouldEmitUTF8Identifier
parameter. -
Pass the
UTF8Encoding
instance to the stream constructor.
' VB.NET:
Dim utf8WithoutBom As New System.Text.UTF8Encoding(False)
Using sink As New StreamWriter("Foobar.txt", False, utf8WithoutBom)
sink.WriteLine("...")
End Using
// C#:
var utf8WithoutBom = new System.Text.UTF8Encoding(false);
using (var sink = new StreamWriter("Foobar.txt", false, utf8WithoutBom))
{
sink.WriteLine("...");
}
2. Using the default encoding:
If you do not supply an Encoding
to StreamWriter
's constructor at all, StreamWriter
will by default use an UTF8 encoding without BOM, so the following should work just as well:
' VB.NET:
Using sink As New StreamWriter("Foobar.txt")
sink.WriteLine("...")
End Using
// C#:
using (var sink = new StreamWriter("Foobar.txt"))
{
sink.WriteLine("...");
}
Finally, note that omitting the BOM is only permissible for UTF-8, not for UTF-16.
"MSDN reference page"
"MSDN reference page"
"MSDN reference page"
Solution 2 - vb.net
Try this:
Encoding outputEnc = new UTF8Encoding(false); // create encoding with no BOM
TextWriter file = new StreamWriter(filePath, false, outputEnc); // open file with encoding
// write data here
file.Close(); // save and close it
Solution 3 - vb.net
Just Simply use the method WriteAllText
from System.IO.File
.
Please check the sample from File.WriteAllText.
> This method uses UTF-8 encoding without a Byte-Order Mark (BOM), so > using the GetPreamble method will return an empty byte array. If it is > necessary to include a UTF-8 identifier, such as a byte order mark, at > the beginning of a file, use the WriteAllText(String, String, > Encoding) method overload with UTF8 encoding.
Solution 4 - vb.net
Interesting note with respect to this: strangely, the static "CreateText()" method of the System.IO.File class creates UTF-8 files without BOM.
In general this the source of bugs, but in your case it could have been the simplest workaround :)
Solution 5 - vb.net
If you do not specify an Encoding
when creating a new StreamWriter
the default Encoding
object used is UTF-8 No BOM
which is created via new UTF8Encoding(false, true)
.
So to create a text file without the BOM use of of the constructors that do not require you to provide an encoding:
new StreamWriter(Stream)
new StreamWriter(String)
new StreamWriter(String, Boolean)
Solution 6 - vb.net
I think Roman Nikitin is right. The meaning of the constructor argument is flipped. False means no BOM and true means with BOM.
You get an ANSI encoding because a file without a BOM that does not contain non-ansi characters is exactly the same as an ANSI file. Try some special characters in you "hi there" string and you'll see the ANSI encoding change to without-BOM.
Solution 7 - vb.net
XML Encoding UTF-8 without BOM
We need to submit XML data to the EPA and their application that takes our input requires UTF-8 without BOM. Oh yes, plain UTF-8 should be acceptable for everyone, but not for the EPA. The answer to doing this is in the above comments. Thank you Roman Nikitin.
Here is a C# snippet of the code for the XML encoding:
Encoding utf8noBOM = new UTF8Encoding(false);
XmlWriterSettings settings = new XmlWriterSettings();
settings.Encoding = utf8noBOM;
…
using (XmlWriter xw = XmlWriter.Create(filePath, settings))
{
xDoc.WriteTo(xw);
xw.Flush();
}
To see if this actually removes the three leading character from the output file can be misleading. For example, if you use Notepad++ (www.notepad-plus-plus.org), it will report “Encode in ANSI”. I guess most text editors are counting on the BOM characters to tell if it is UTF-8. The way to clearly see this is with a binary tool like WinHex (www.winhex.com). Since I was looking for a before and after difference I used the Microsoft WinDiff application.
Solution 8 - vb.net
For VB.Net visual basic, this is how to make it work:
My.Computer.FileSystem.WriteAllText("FileName", Data, False, System.Text.Encoding.ASCII)
Solution 9 - vb.net
It might be that your input text contains a byte order mark. In that case, you should remove it before writing.
Solution 10 - vb.net
Dim sWriter As IO.StreamWriter = New IO.StreamWriter(shareworklist & "\" & getfilename() & ".txt", False, Encoding.Default)
Gives you results as those you want(I think).