Unicode到ASCII以及umlats的字符转换

Question

I have a client that sends unicode input files and demands only ASCII encoded files in return - why is unimportant.

Does anyone know of a routine to translate unicode string to a closest approximation of an ASCII string? I'm looking to replace common unicode characters like 'ä' to a best ASCII representation.

For example: 'ä' -> 'a'

Data resides in SQL Server however I can also work in C# as a downstream mechanism or as a CLR procedure.

Answer 1

Just loop through the string. For each character do a switch:

switch(inputCharacter)
{
    case 'ä':
      outputString = "ae";
      break;
    case 'ö':
      outputString = "oe";
      break;
...

(These translations are common in german language with ASCII only)

Then combine all outputStrings with a StringBuilder.

Answer 2

I think you really mean extended ASCII to ASCII
Just a simple dictionary

Dictionary<char, char> trans = new Dictionary<char, char>() {...}  
StringBuilder sb = new StringBuilder();
foreach (char c in string.ToCharArray)
{
     if((Int)c <= 127) 
         sb.Append(c);
     else
         sbAppend(trans[c]);
}
string ascii = sb.ToString();