private void LeftMouseDown(MouseEventArgs e)
{
Point currentLocation = e.Location;
this._clickLocation = currentLocation;
Element.Element currentSelected = null;
#region 节点Select检查
for (int idx = this._nodes.Count - 1; idx >= 0; idx--)
{
NodeElement node = this._nodes[idx];
if (node.CaughtBy(currentLocation))
{
currentSelected = node;
break;
}
else
{
AnchorElement anchor = node.AnchorCaughtBy(currentLocation);
if (anchor != null)
{
currentSelected = anchor;
break;
}
}
}
#endregion
#region 连接Select检查
for (int idx = this._connections.Count - 1; idx >= 0; idx--)
{
ConnectionElement conn = this._connections[idx];
if (conn.CaughtBy(currentLocation))
{
currentSelected = conn;
break;
}
}
#endregion
#region 更新当前被选择的元素
if (currentSelected != this._theSelected)
{
if (currentSelected != null)
{
currentSelected.Selected = true;
}
if (this._theSelected != null)
{
this._theSelected.Selected = false;
}
this._theSelected = currentSelected;
}
#endregion
this._dragging = true;
// 若为锚点，则开始进行连接行为
if (!(this._theSelected is AnchorElement from))
{
return;
}
AnchorElement tempTo = ElementFactory.AnchorElement(currentLocation.X, currentLocation.Y, null, this);
ConnectionElement tempConn = ElementFactory.ConnectionElement(@from, tempTo, this);
this._tempConnection = tempConn;
@from.Selected = false;
tempTo.Selected = true;
this._theSelected = tempTo;
}