There are two version issues that you may need to consider when building and running your application: the version of Adobe PDF Library in use, and the declared PDF version (or Compliance Level) being declared within the PDF output being generated.
Obtaining Adobe PDF Library Version Number
The version number of the Adobe PDF Library which was initialized may be obtained at any time after initialization as the return value of the method HFTGetVersion:
- The high-order 16 bits of the value are the Major Version Number
- bits 8 through 15 are the Minor Version Number
- bits 0 through 7 are the Sub-minor Version Number
You may wish to have your application obtain and compare the returned Version Number to the constant kPDFLVersion to see if the version of the Adobe PDF Library being used at runtime is the same, greater, or less than the Version Number of with which it was compiled.
PDF Level Declarations in Output
PDF output files declare their compliance level with a particular version of the PDF Standard. For example, documents created with Adobe PDF Library v18 can declare a standard of PDF v 2.0.
Applications reading, processing or displaying PDF output may inspect the declaration within the file to determine how to process it. In particular, Adobe Acrobat and Reader applications may produce a popup warning of possible unsupported PDF features if they detect that the declared PDF level of the document is higher than the current PDF revision level at the time they were released.
Earlier versions of the Adobe PDF Library declare a baseline compliance level of PDF v1.6 in the output documents it creates. If you need to raise the minimum PDF value declaration due to newer version, you must call the PDDocSetMinorVersion method to set the appropriate value.
NOTE: Viewing a latest-generation PDF in an earlier version of Adobe Acrobat or Adobe Reader can produce a popup warning of a PDF level mismatch, to warn the user that certain PDF features new to that version may not be supported by the viewing program. While this is only a warning, it may concern some users who have not upgraded to the latest viewer. You should ensure that your document features are backwards-compatible to older viewer versions where possible, or warn your users that a viewer upgrade will be required in order to take full advantage of features in your document, as appropriate.