public async static Task <string> ConvertToBase64(string fileName)
{
if (!File.Exists(fileName))
{
return(string.Empty);
}
string format = "data:{0};base64,{1}";
byte[] buffer = await FileHelpers.ReadAllBytesRetry(fileName);
string extension = Path.GetExtension(fileName).Substring(1);
string contentType = GetMimeTypeFromFileExtension(extension);
return(string.Format(CultureInfo.InvariantCulture, format, contentType, Convert.ToBase64String(buffer)));
}