public static void ReplaceUrlFileFormat(ref string content)
{
string f4vPattern = "/Juno/school/videos/(?<fileName>.+?).f4v";
string swfPattern = "/Juno/school/videos/(?<fileName>.+?).swf";
//step2: replace /Juno/school/videos/1.f4v to /Juno/school/videos/1.mp4
ChangeContent(ref content, f4vPattern,
match => string.Format("/Juno/school/videos/{0}.mp4", Uri.UnescapeDataString(match.Groups["fileName"].ToString()))
);
//step3: replace "/Juno/school/videos/1.swf" to "/Juno/school/imgs_epaper/1.jpg"
ChangeContent(ref content, swfPattern,
match => string.Format("/Juno/school/imgs_epaper/{0}.jpg", Uri.UnescapeDataString(match.Groups["fileName"].ToString()))
);
}