文字数を数える

Program.cs

static int GetLength( string value )
{
    return value.Length;
}

static int GetLengthInTextElements( string value )
{
    var sinfo = new StringInfo( value );
    return sinfo.LengthInTextElements;
}

static void Main( string[ ] args )
{
    var str = "𠮟咤する";
    Console.WriteLine( "Length: {0}", GetLength( str ) );
    Console.WriteLine( "LengthInTextElements: {0}", GetLengthInTextElements( str ) );
}

標準出力

Length: 5
LengthInTextElements: 4