Match multiple lines with a regex in C#

I have the following text:

--------------030805090908050805080502
Content-Type: image/jpeg
Content-Transfer-Encoding: base64
Content-ID: <part16.07030906.00090703@highcontrast.ro>

/9j/4AAQSkZJRgABAgAAZABkAAD/7AARRHVja3kAAQAEAAAARgAA/+4ADkFkb2JlAGTAAAAA
/9j/4AAQSkZJRgABAgAAZABkAAD/7AARRHVja3kAAQAEAAAARgAA/+4ADkFkb2JlAGTAAAAA
QBQH/9k=
--------------030805090908050805080502
Content-Type: image/jpeg
Content-Transfer-Encoding: base64
Content-ID: <part17.07010805.02020809@highcontrast.ro>

/9j/4AAQSkZJRgABAgAAZABkAAD/7AARRHVja3kAAQAEAAAARgAA/+4ADkFkb2JlAGTAAAAA
/9j/4AAQSkZJRgABAgAAZABkAAD/7AARRHVja3kAAQAEAAAARgAA/+4ADkFkb2JlAGTAAAAA
juu41lRHFLufPCAID//Z
--------------030开发者_如何学Go805090908050805080502--

And I need to get with Regex in C# 2 parts:

1. between the first and the second occurence of the string "--------------030805090908050805080502"
2. between the strings "--------------030805090908050805080502" and "--------------030805090908050805080502--"

I tried this regex:

--------------030805090908050805080502(\r.*)*--------------030805090908050805080502

but in C# regex.Matches(...) returns only "--------------030805090908050805080502".

MatchCollection matches = Regex.Matches( text, @"([-]+\d{24})
                                                 (?<Content>.*?)
                                                 (?=\1)", 
                                         RegexOptions.IgnorePatternWhitespace | 
                                         RegexOptions.Singleline );

foreach ( Match match in matches )
{
    Console.WriteLine( 
        string.Format( "match: {0}\n\n", 
                       match.Groups[ "Content" ].Value ) );
}

Update: This expression will find all matches that come between two occurrences of a number. If the number needs to be a specific one, rather than any 24-digit number, change "\d{24}" to the number you want to match.

Have you tried a Split:

var str = stringToParse.Split(
    new[] { "--------------030805090908050805080502" }, 
    StringSplitOptions.None);
Console.WriteLine(str[1]);