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IHTMLElement stored as Object in CheckListBox

I am storing the "pointer' to an IHTMLElement in a CheckListbox like this:

Root := DomNode.parentnode.parentnode.parentnode.parentnode as IHTMLElement;
CheckListBox1.Items.AddObject(GetName(DomNode.nodeValue), TObject(Root));

Now I want to get the object back so I can get to it's outerHTML value.

These aren't working:
TObject(CheckListBox1.Items.Objects[i]^) as IHTMLElement;
TObject(CheckListBox1.Items.Objects[i]) as IHTMLElement;
IHTMLElement(TObject(CheckListBox1.Items.Objects[i]));

what am I doing wrong, here?

Russell Libby

The smart pointer is getting in your way (I believe, hard to tell with the code clip), because Root is a local var, and it is dropping the ref count and releasing the interface when it goes out of scope. This leaves you with a couple options.

1. Manually _addref when adding to the checklistbox, and _release when you are done with it.
2. Use a TInterfaceList to add the interfaces to, and store the index of the list as the checklist item object
3. Use a pointer to store the interface so that the compiler does not auto addref/release the interface, eg:

var pvItem: Pointer;
begin

// Make sure pointer is cleared, because the interface cast will cause the
// pointer to be released if non nil, which would be bad...
pvItem:=nil;

// Get addref'd interface as pointer, which will keep the compiler from releasing it
IHTMLElement(pvItem):=DomNode.parentnode.parentnode.parentnode.parentnode as IHTMLElement;

// Add to list
CheckListBox1.Items.AddObject(GetName(DomNode.nodeValue), TObject(pvItem));

...

// To cleanup correctly and perform the release
IHTMLElement(pvItem):=nil;

Number 2 will most likely be the least error prone, but all 3 are valid.

Regards,
Russell

Eddie Shipman

ASKER

root is a global var to the form.

You didn't show how to get it back into another IHTMLElement object.

ASKER CERTIFIED SOLUTION

Russell Libby

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Eddie Shipman

ASKER

Once again Russell, you have the correct answer.

I didn't know about TInterfaceList. Now I have it working...

Thanks.

Eddie Shipman

ASKER

Hey, Russell, if I store the interface in the InterfaceList and loop the document again, will
the outerHTML change? I am doing this and it is not returning the same outerHTML ass when
I placed it in the list.

Eddie Shipman

ASKER

nevermind, I'll post another question about commenting out sections of code in an IHTMLDocument2.