How do I unlock Foxit Quick PDF Library with my license key?

To unlock Foxit Quick PDF Library so that it is not limited in anyway you need to use the UnlockKey function with your commercial or trial license key after you have initiated the library.

The UnlockKey function returns a value to indicate whether or not the library could be unlocked:

0 = The library could not be unlocked
1 = The library was unlocked successfully

When using the UnlockKey it’s always a good idea to check the return value of this function so
that you know whether your application is going to work correctly or not. For example:

Dim ClassName
Dim LicenseKey
Dim FileName 
 
ClassName = "DebenuPDFLibraryAX.PDFLibrary"
LicenseKey = "..." // INSERT LICENSE KEY HERE
FileName = "C:\Hello-World-From-DQPL.pdf" 
 
Dim DPL
Dim Result 
 
Set DPL = CreateObject(ClassName)
Result = DPL.UnlockKey(LicenseKey) 
 
If Result = 1 Then 
   MsgBox "Library version: " + DPL.LibraryVersion
   MsgBox (DPL.LicenseInfo)    Call DPL.DrawText(100, 500, "Hello world from Visual Basic 6") 
 
   If DPL.SaveToFile(FileName) = 1 Then 
     MsgBox "File " + FileName + " written successfully." 
   Else 
     MsgBox "Error, file could not be written." 
   End If 
 
Else 
   MsgBox "Invalid license key. Please set a valid license key." 
End If 
 
Set DPL = Nothing

If the library is not successfully unlocked then you will run into various problems which will mean your application won’t work correctly. So again, it’s important to check the return value of the UnlockKey function!