C# copy string to byte buffer

arrays, c#, string

Solution

If the buffer is big enough, you can just write it directly:

encoding.GetBytes(mystring, 0, mystring.Length, buffer, 0)

However, you might need to check the length first; a test might be:

if(encoding.GetMaxByteCount(mystring.length) <= buflen // cheapest first
   || encoding.GetByteCount(mystring) <= buflen)
{
    return encoding.GetBytes(mystring, 0, mystring.Length, buffer, 0)
}
else
{
    buffer = encoding.GetBytes(mystring);
    return buffer.Length;
}

after that, there is nothing to do, since you are already passing `buffer` out by `ref`. Personally, I suspect that this `ref` is a bad choice, though. There is no need to `BlockCopy` here, unless you were copying from a scratch buffer, i.e.

var tmp = encoding.GetBytes(mystring);
// copy as much as we can from tmp to buffer
Buffer.BlockCopy(tmp, 0, buffer, 0, buflen);
return buflen;

Problem

I am trying to copy an Ascii string to a byte array but am unable. How? Here are the two things I have tried so far. Neither one works: ``` public int GetString (ref byte[] buffer, int buflen) { string mystring = "hello world"; // I have tried this: System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding(); buffer = encoding.GetBytes(mystring); // and tried this: System.Buffer.BlockCopy(mystring.ToCharArray(), 0, buffer, 0, buflen); return (buflen); } ```

Original source