how to remove the pages of QToolBox?

[ChrisW67]

Now if click on"clear" button, all the pages except 1st page should remove...
How can i do that?

By removing all the items except the first

I tried using
void QToolBox::removeItem ( int index )
but it is not deleting the removed item....

As the friendly docs say,

void QToolBox::removeItem ( int index )

Removes the item at position index from the toolbox. Note that the widget is not deleted.

If you want the object deleted, then delete it yourself.