From Tracker Software PDF SDK
Changes state of an item in a dialog to checked or unchecked by item's numerical ID.
HRESULT CheckItem2([in] LONG nItemID, [in] LONG nNewCheckState, [in, defaultvalue(-1)] VARIANT_BOOL bUpdateRadioGroup);
- [in] numerical ID of an item that is to be checked/unchecked.
- [in] Checks an item if set to TRUE, unchecks if set to FALSE.
- [in, defaultvalue(-1)] if set to VARIANT_TRUE, updates state of all radio boxes of the same group unchecking items that were in a checked state.
Returns S_OK if the operation was successful, or will return an error code if it fails.