用下面的代码展开TreeView1的节点:
For i = 1 To TreeView1.Nodes.Count
TreeView1.Nodes(i).EnsureVisible
Next i
TreeView1.Refresh
For i = 1 To TreeView1.Nodes.Count
TreeView1.Nodes(i).EnsureVisible
Next i
TreeView1.Refresh
设置所有的 Node.Expanded=False 折叠