public DragDropResult(TreeNodePro[] dragdropNodes, TreeNodePro dropNode, DragDropResultType dropResultType)
{
_dragdropNodes = dragdropNodes;
_dropPutNode = dropNode;
_dropResultType = dropResultType;
}
protected override void OnPaint(PaintEventArgs e)
{
//如果其顺序有效，且在拖动，则在拖拽处画条横线，指示插入点
if (CanOrder && _isDragDrop)
{
Point mousePosition = PointToClient(Control.MousePosition);
TreeNodePro mouseNode = (TreeNodePro)this.GetNodeAt(mousePosition);
bool mouseNodeIsNull = false;
///鼠标当前位置没有TreeNode，那么认为鼠标在最后一个TreeNode之后
if (mouseNode == null)
{
mouseNodeIsNull = true;
mouseNode = (TreeNodePro)this.Nodes[this.Nodes.Count - 1];
}
if (!mouseNodeIsNull)
{
///检测拖拽结果
DragDropResultType dropResultType = GetDragDropResult();
if (mouseNode != _dropResultNode || dropResultType != _dropResultType)
{
switch (dropResultType)
{
///鼠标在目标节点之前
case DragDropResultType.Before:
{
_lineBeginPoint = new Point(mouseNode.Bounds.X - 20, mouseNode.Bounds.Y);
_lineEndPoint = new Point(mouseNode.Bounds.X + _InsertLineWidth, mouseNode.Bounds.Y);
DrawInsertLine(e.Graphics, _lineBeginPoint.X, _lineBeginPoint.Y, CurrentNode.Bounds.Width);
break;
}
///鼠标在目标节点之后
case DragDropResultType.After:
{
_lineBeginPoint = new Point(mouseNode.Bounds.X - 20, mouseNode.Bounds.Y + mouseNode.Bounds.Height);
_lineEndPoint = new Point(mouseNode.Bounds.X + _InsertLineWidth, mouseNode.Bounds.Y + mouseNode.Bounds.Height);
DrawInsertLine(e.Graphics, _lineBeginPoint.X, _lineBeginPoint.Y, CurrentNode.Bounds.Width);
break;
}
}
///只有在线画完后才将当前值存储起来
_dropResultType = dropResultType;
_dropResultNode = mouseNode;
}
}
}
base.OnPaint(e);
}
public DragDropResult(TreeNodePro[] dragdropNodes, TreeNodePro dropNode, DragDropResultType dropResultType)
{
_dragdropNodes = dragdropNodes;
_dropPutNode = dropNode;
_dropResultType = dropResultType;
}
