protected override void OnMouseDown(MouseEventArgs e)
{
Point locate = new Point(
e.X + HorizontalScroll.Value,
e.Y + VerticalScroll.Value);
if (e.Button == MouseButtons.Left)
{
clickedItem = GetItemAtPoint(locate);
if (clickedItem != null)
{
if (clickedItem is CustomItemNode)
{
if (!drawingLine)
{
clickedItemPoint =
new Point(
locate.X - clickedItem.ItemLocate.X,
locate.Y - clickedItem.ItemLocate.Y);
}
else
{
if (!(clickedItem is ItemEnd))
{
currentDrawingLine = CreateWorkFlowLine();
currentDrawingLine.ItemStatus = ItemStatus.Drawing;
currentDrawingLine.ItemFrom = clickedItem as CustomItemNode;
}
}
}
}
}
base.OnMouseDown(e);
}
private bool LinkLineExists(ItemLink link)
{
foreach (ItemLink itemLink in link.ItemFrom.NextLinks)
{
if (link.ItemFrom == itemLink.ItemFrom && link.ItemTo == itemLink.ItemTo)
{
return(true);
}
}
return(false);
}
/// <summary>
/// 新建连接线后的链路校验。
/// 缺省的检验是：如果形成闭合循环，则返回 false，否则返回 true
/// </summary>
protected virtual bool CheckValid(ItemLink link, CustomItemNode node)
{
if (NodeInPrevRouting(link, node))
{
MessageBox.Show(
"当前流程不支持闭合循环！",
"链路错误",
MessageBoxButtons.OK,
MessageBoxIcon.Error);
return(false);
}
else
{
return(true);
}
}
protected override void OnMouseUp(MouseEventArgs e)
{
Point location = new Point(
e.X + HorizontalScroll.Value,
e.Y + VerticalScroll.Value);
if (e.Button == MouseButtons.Left)
{
if (drawingLine)
{
if (currentDrawingLine != null)
{
IPaintItem item = GetItemAtPoint(location);
if (item != null && item is CustomItemNode)
{
if (item == currentDrawingLine.ItemFrom)
{
}
else if (item is ItemBegin)
{
}
else
{
if (CheckValid(
currentDrawingLine,
item as CustomItemNode))
{
currentDrawingLine.ItemStatus = ItemStatus.Watting;
currentDrawingLine.ItemTo = item as CustomItemNode;
if (!LinkLineExists(currentDrawingLine))
{
currentDrawingLine.ItemTo.PrevLinks.Add(currentDrawingLine);
currentDrawingLine.ItemFrom.NextLinks.Add(currentDrawingLine);
}
}
}
}
currentDrawingLine = null;
}
}
}
base.OnMouseUp(e);
}
/// <summary>
/// 检查指定的结点是否是当前连接线的起始结点
/// </summary>
protected virtual bool NodeInPrevRouting(ItemLink link, CustomItemNode node)
{
if (link.ItemFrom == node)
{
return(true);
}
else
{
foreach (ItemLink prevLink in link.ItemFrom.PrevLinks)
{
if (NodeInPrevRouting(prevLink, node))
{
return(true);
}
}
}
return(false);
}