Treeview的Node拖动Node节点移动

Treeview的Node拖动Node节点位置移动并重新排序存储。

关键代码：

private void treeView1_DragDrop(object sender, DragEventArgs e)//拖动
       {
           //获得拖放中的节点
           TreeNode moveNode = (TreeNode)e.Data.GetData("System.Windows.Forms.TreeNode");
           /* 根据鼠标坐标确定要移动到的目标节点     */
           Point pt;
           TreeNode targeNode;
           pt = ((TreeView)(sender)).PointToClient(new Point(e.X, e.Y));
           targeNode = this.treeView1.GetNodeAt(pt);
           TreeNode newMoveNode = (TreeNode)moveNode.Clone();
           bool isNeedToSort = false;
           /* 要移动及目标node为根节点，添加到根同级；否则放到本结点同级*/
           if (targeNode.Parent == null && this.mHTRootItem.ContainsKey(moveNode.Name))
           {
               treeView1.Nodes.Insert(targeNode.Index, newMoveNode);
               treeView1.SelectedNode = newMoveNode;
               moveNode.Remove();
               isNeedToSort = true;
           }
           /* 目标节点为非根节点且*/
           else if(targeNode.Parent != null && this.mHTItemChild.ContainsKey(targeNode.Name))
           {
               string parentFlagKey = string.Empty;
               Structs.ItemChild childNodeSrc = (Structs.ItemChild)this.mHTItemChild[moveNode.Name];
               Structs.ItemChild childNodeDest = (Structs.ItemChild)this.mHTItemChild[targeNode.Name];
               if (childNodeDest.ParentFlagKey == childNodeSrc.ParentFlagKey)
               {
                   targeNode.Parent.Nodes.Insert(targeNode.Index, newMoveNode);
                   treeView1.SelectedNode = newMoveNode;
                   moveNode.Remove();
                   isNeedToSort = true;
               }
           }
           targeNode.Expand();
           if (!isNeedToSort)
               return;
           /* Resort the field of sequence */
           string flagKey = string.Empty;
           if (targeNode.Parent == null) // Root Node
           {
               Structs.ItemRoot root;
               for (int i = 0; i < treeView1.Nodes.Count; i++)
               {
                   flagKey = treeView1.Nodes[i].Name;
                   root = (Structs.ItemRoot)this.mHTRootItem[flagKey];
                   root.Sequence = i;
                   this.mHTRootItem.Remove(flagKey);
                   DBOperator.UpdateItemRoot(root);
                   this.mHTRootItem.Add(flagKey, root);
               }
           }
           else
           {
               Structs.ItemChild child;
               for (int i = 0; i < targeNode.Parent.Nodes.Count; i++)
               {
                   flagKey = targeNode.Parent.Nodes[i].Name;
                   child = (Structs.ItemChild)this.mHTItemChild[flagKey];
                   child.Sequence = i;
                   this.mHTItemChild.Remove(flagKey);
                   DBOperator.UpdateItemChild(child);
                   this.mHTItemChild.Add(flagKey, child);
               }
           }// end else
       }

DB及DBAPI设计：

构建根子树的技巧：

private void buildTreeView()
{
    this.treeView1.Nodes.Clear();
    this.mHTRootItem.Clear();
    this.mHTItemChild.Clear();
    Structs.ItemRoot[] rootRecords = null;
    DBOperator.GetItemRoot(out rootRecords);
    if (rootRecords == null)
        return;
    for (int i =0;i {
        this.mHTRootItem.Add(rootRecords[i].FlagKey, rootRecords[i]);
        TreeNode newNode = treeView1.Nodes.Add(rootRecords[i].Title);
        newNode.Name = rootRecords[i].FlagKey.ToString();
        newNode.ImageIndex = 0;
        newNode.SelectedImageIndex = 1;
        AddChild(newNode);
    }
    this.treeView1.ExpandAll();
}
private void AddChild(TreeNode parentNode)
{
    if (parentNode == null)
        return;
    string parentFlagKey = parentNode.Name;
    Structs.ItemChild[] childRecords = null;
    DBOperator.GetItemChild(out childRecords,parentFlagKey);
    if (childRecords == null)
        return;
    for (int i = 0; i < childRecords.Length;i++)
    {
        this.mHTItemChild.Add(childRecords[i].FlagKey, childRecords[i]);
        TreeNode newNode = parentNode.Nodes.Add(childRecords[i].Title);
        newNode.Name = childRecords[i].FlagKey;
        newNode.ImageIndex = 2;
        newNode.SelectedImageIndex = 3;
        AddChild(newNode);
    }
}

参考文献：