UTF8 encoding

OK, I changed it to:

sUTF8=System.Text.Encoding.UTF8.GetString(System.Text.Encoding.GetEncoding("Unicode").GetBytes(sUTF16))
(because "UTF16" is not a valid encoding name)
or indeed :
sUTF8=System.Text.Encoding.UTF8.GetString(System.Text.Encoding.Unicode.GetBytes(sUTF16))

but it doesn't work, try it, if you set sUTF16 = "ë" then the return sUTF8 is empty.

I come from the world of Delphi, where this is done simply:
sUTF8 := UTF8Encode(sUTF16);
I'm finding it particularly frustrating that such a simple transform is proving so elusive in C#, have I completely missed the point somewhere along the way?

"string"s are always unicode. Internally I believe a UTF-16 is used.

It looks like You want to get the byte[] representation of it?

        string inputString = "ÄÖÜ";
        byte[] buffer = Encoding.UTF8.GetBytes(inputString);

o.k.
I think I now know what you mean,
when we did System.Text.Encoding.UTF8.GetString()
It would actuall create a string based on the assumption that the bytes of the input are encoded to be UTF8
which is both not true and not what you wanted.

and you think that the unicode representation of ë is two bytes which as single bytes translate to à  and « ?

However, when I run
byte[] chars=System.Text.Encoding.Unicode.GetBytes("ë");
I get two bytes which are 0xeb & 0x00.

while translating à  and « gives my 0x3f & 0xab respectively.

neither of
Response.Write(System.Text.Encoding.Unicode.GetString(new byte[]{0x3f,0xab}));
Response.Write(System.Text.Encoding.Unicode.GetString(new byte[]{0xab,0x3f}));

returned "ë"

could you explain why you want/expect "ë" to convert to "ë" ?

SnowFlake

For all the "rules" about unicode have a look at "http://www.unicode.org/", please.

I would recomand this:
"The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!)"
http://www.joelonsoftware.com/articles/Unicode.html

which is somwhat less formal but very good reading.

SnowFlake

The following code will do the conversion:

using System.Text;

sUTF8 = new DirectEncoding().GetString(System.Text.Encoding.UTF8.GetBytes(sUTF16))

public class DirectEncoding : Encoding
{
      public override int GetByteCount(char[] chars, int index, int count)
      {
            return count;
      }

      public override int GetBytes(char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex)
      {
            for (int i=0; i<charCount; i++)
            bytes[byteIndex+i]=(int)chars[charIndex+i]>255 ? (byte)'?' : (byte)chars[charIndex+i];
            return charCount;
      }

      public override int GetCharCount(byte[] bytes, int index, int count)
      {
            return count;
      }

      public override int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex)
      {
            for (int i=0; i<byteCount; i++)
                  chars[charIndex+i]=(char)bytes[byteIndex+i];
            return byteCount;
      }

      public override int GetMaxByteCount(int charCount)
      {
            return charCount;
      }

      public override int GetMaxCharCount(int byteCount)
      {
            return byteCount;
      }
}

>> could you explain why you want/expect "ë" to convert to "ë"

because the UTF8 encoding of the UTF16 character "ë" (0x00EB) is (0xC3 0xAB) which, under my local codepage, displays as: "ë"

Granted, without specifying the codepage, quoting the UTF8 bytes as characters was a little silly, but I took the gamble that they would display similarly on others systems.


Bear with me for the rest of the comments, I have actually solved the problem now, but I want to look at what you've all suggested...

glad I could help,
thanks for the grade and points,
It would be nice if you add few words about what turned out to be the problem
for those that will read this in the future.

SnowFlake