UPDATE - 22nd Oct 2005
Andrea Fox from the SSIS documentation team has picked up issue #2 below and is running with it. It turns out that you can use an object of type Variables if you're building a custom task but not when building a custom data-flow component. In that case only the IDTSVariables90 object works.
BOL will be changed accordingly therefore and I would expect that there will be a fix before too long that allows you to use Variables in a component.
-Jamie
More useful stuff that I've picked up in the last few days...
1) If you're using a datareader destination component do not have DelayValidation=TRUE on the data-flow task or else you will not be able to consume data from the datareader destination. This is a bug - thanks to Runying Mao at Microsoft for helping me find it!
2) If you're building a custom taskcomponent and you want to access package variables use the VariableDispenser as follows:
Dim vars as IDTSVariables90 = NOTHING
Me.VariableDispenser.LockForRead("User::Variable")
Me.VariableDispenser.LockForRead("System::ContainerStartTime")
Me.VariableDispenser.GetVariables(vars)
...
...
vars.Unlock()
BOL says to use the following:
Dim vars as Variables = NOTHING
Me.VariableDispenser.LockForRead("User::Variable")
Me.VariableDispenser.LockForRead("System::ContainerStartTime")
Me.VariableDispenser.GetVariables(vars)
...
...
vars.Unlock()
and that is WRONG!!!! It will fail. I've informed Microsoft of this - hopefully they'll pick it up and change BOL soon!
-Jamie