Question
I’m using phGantXControl.ocx
What is the difference between the classes CphDataEntity_Tree and CphDataEntity_Tree2?
I have a CphDataEntity_GantTime item and I want to access to grid rows. It seems that the only way to do this is to use the property GridRowIndex of the class CphDataEntity_Tree2, but I cannot get any CphDataEntity_Tree2 item from my CphDataEntity_GantTime item.
Answer
This is the naming convention when designing a new interface with more functionality: Ix = version one of the interface; Ix2 = version two of the interface.
So CphDataEntity_Tree2 is only a more competent version of
CphDataEntity_Tree.
You can type cast from a CphDataEntity_Tree to a CphDataEntity_Tree2 to access the extended functionality with QueryInterface
This is from the help file, the section called “Understanding interfaces”
Type casting
In VB6 you can do a interface type casting like this:
Dim tn As IphDataEntity_Tree2
Set tn = theDataEntity.Row.TreeNode
The “theDataEntity.Row.TreeNode” returns a IphDataEntity_Tree but we want to use it as an IphDataEntity_Tree2 in order to reach newer functionality.
In Delphi you would do it like this
tn : IphDataEntity_Tree2;
begin
tn := theDataEntity.Row.TreeNode As IphDataEntity_Tree2;
In VC++ you would do it like this:
CphDataEntity_Tree2 treenode;
treenode=CphDataEntity_Tree2(theDataEntity.GetRow().GetTreeNode());
.
