Копировать узлы с поддеревом TTreeView во второй TTreeView
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Копировать узлы с поддеревом TTreeView во второй TTreeView[править | править код]
type
{: Callback to use to copy the data of a treenode when the
node itself is copied by CopySubtree.
@param oldnode is the old node
@param newnode is the new node
@Desc Use a callback of this type to implement your own algorithm
for a node copy. The default just uses the Assign method, which
produces a shallow copy of the nodes Data property. }
TCopyDataProc = procedure(oldnode, newnode: TTreenode);
{: The default operation is to do a shallow copy of the node, via Assign. }
procedure DefaultCopyDataProc(oldnode, newnode: TTreenode);
begin
newnode.Assign(oldnode);
end;
{-- CopySubtree -------------------------------------------------------}
{: Copies the source node with all child nodes to the Target TTreeView.
@Param SourceNode is the node to copy
@Param Target is the treeview to insert the copied nodes into
@Param TargetNode is the node to insert the copy under, can be nil to
make the copy a top-level node.
@Param CopyProc is the (optional) callback to use to copy a node.
If Nil is passed for this parameter theDefaultCopyDataProc will be
used.
@Precondition SourceNode <> nil, Target <> nil, TargetNode is either
nil or a node of Target
@Raises Exception if TargetNode happens to be in the subtree rooted in
SourceNode. Handling that special case is rather complicated, so we
simply refuse to do it at the moment. }
{ Created 2003-04-09 by P. Below
-----------------------------------------------------------------------}
procedure CopySubtree(SourceNode: TTreenode; Target: TTreeView;
TargetNode: TTreeNode; CopyProc: TCopyDataProc = nil);
var
Anchor: TTreenode;
Child: TTreenode;
begin { CopySubtree }
Assert(Assigned(SourceNode), 'CopySubtree:sourcenode cannot be nil');
Assert(Assigned(Target), 'CopySubtree: target treeview cannot be nil');
Assert((TargetNode = nil) or (TargetNode.TreeView = Target),
'CopySubtree: targetnode has to be a node in the target treeview.');
if (SourceNode.TreeView = Target)
and (TargetNode.HasAsParent(SourceNode)
or (SourceNode = TargetNode)) then
raise Exception.Create('CopySubtree cannot copy a subtree to one of the ' +
'subtrees nodes.');
if not Assigned(CopyProc) then
CopyProc := DefaultCopyDataProc;
Anchor := Target.Items.AddChild(TargetNode, SourceNode.Text);
CopyProc(SourceNode, Anchor);
Child := SourceNode.GetFirstChild;
while Assigned(Child) do
begin
CopySubtree(Child, Target, Anchor, CopyProc);
Child := Child.GetNextSibling;
end;
end;
procedure TForm1.Button1Click(Sender : TObject);
begin
if Assigned(TreeView1.Selected) then
CopySubtree(TreeView1.Selected, TreeView2, nil);
end;
Source: Взято с сайта: http://www.swissdelphicenter.ch
ID: 01116