/// <summary>
/// The getHashSHA1 method obtain a string representing the calculated hash of the current document for unique identification.
/// </summary>
/// <returns></returns>
public string getHashSHA1()
{
StringBuilder buffer = new StringBuilder(41);
Check(ISYS11df.IGR_Calculate_SHA1(NeedStream(), buffer, ref ecb), ecb);
return(buffer.ToString());
}
