private void ResetPrevTarget()
{
if (m_LastTarget != null)
{
//ShowCnt("RSP Prior to LT.DragLeave")
int hr = m_LastTarget.DragLeave();
//ShowCnt("RSP After LT.DragLeave")
Marshal.ReleaseComObject(m_LastTarget);
//ShowCnt("RSP After Release of LT")
m_LastTarget = null;
m_LastNode = null;
}
}
private void ResetPrevTarget()
{
if (m_LastTarget != null)
{
//ShowCnt("RSP Prior to LT.DragLeave")
int hr = m_LastTarget.DragLeave();
//ShowCnt("RSP After LT.DragLeave")
Marshal.ReleaseComObject(m_LastTarget);
//ShowCnt("RSP After Release of LT")
m_LastTarget = null;
m_LastNode = null;
}
}
//Private Sub ShowCnt(ByVal S As String)
// If Not IsNothing(m_DragData) Then
// Debug.WriteLine(S & " RefCnt = " & Marshal.AddRef(m_DragData) - 1)
// Marshal.Release(m_DragData)
// End If
//End Sub
public int DragOver(int grfKeyState, Point pt, ref int pdwEffect)
{
//Debug.WriteLine("In DragOver: Effect = " & pdwEffect & " Keystate = " & grfKeyState)
TreeNode tn;
System.Drawing.Point ptClient = m_View.PointToClient(new System.Drawing.Point(pt.X, pt.Y));
tn = ((TreeView) m_View).GetNodeAt(ptClient);
if (tn == null) //not over a TreeNode
{
ResetPrevTarget();
}
else //currently over Treenode
{
if (m_LastNode != null) //not the first, check if same
{
if (tn == m_LastNode)
{
//Debug.WriteLine("DragOver: Same node")
return 0; //all set up anyhow
}
else
{
ResetPrevTarget();
m_LastNode = tn;
}
}
else //is the first
{
ResetPrevTarget(); //just in case
m_LastNode = tn; //save current node
}
//Drag is now over a new node with new capabilities
CShItem CSI = tn.Tag as CShItem;
if (CSI.IsDropTarget)
{
m_LastTarget = CSI.GetDropTargetOf(m_View) as ShellDll.IDropTarget;
if (m_LastTarget != null)
{
pdwEffect = m_Original_Effect;
//ShowCnt("Prior to LT.DragEnter")
int res = m_LastTarget.DragEnter(m_DragDataObj, grfKeyState, pt, ref pdwEffect);
if (res == 0)
{
//ShowCnt("Prior to LT.DragOver")
res = m_LastTarget.DragOver(grfKeyState, pt, ref pdwEffect);
//ShowCnt("After LT.DragOver")
}
if (res != 0)
{
Marshal.ThrowExceptionForHR(res);
}
}
else
{
pdwEffect = 0; //couldn't get IDropTarget, so report effect None
}
}
else
{
pdwEffect = 0; //CSI not a drop target, so report effect None
}
if (ShDragOverEvent != null)
ShDragOverEvent(tn, ptClient, grfKeyState, pdwEffect);
}
return 0;
}
//Private Sub ShowCnt(ByVal S As String)
// If Not IsNothing(m_DragData) Then
// Debug.WriteLine(S & " RefCnt = " & Marshal.AddRef(m_DragData) - 1)
// Marshal.Release(m_DragData)
// End If
//End Sub
public int DragOver(int grfKeyState, Point pt, ref int pdwEffect)
{
//Debug.WriteLine("In DragOver: Effect = " & pdwEffect & " Keystate = " & grfKeyState)
TreeNode tn;
System.Drawing.Point ptClient = m_View.PointToClient(new System.Drawing.Point(pt.X, pt.Y));
tn = ((TreeView)m_View).GetNodeAt(ptClient);
if (tn == null) //not over a TreeNode
{
ResetPrevTarget();
}
else //currently over Treenode
{
if (m_LastNode != null) //not the first, check if same
{
if (tn == m_LastNode)
{
//Debug.WriteLine("DragOver: Same node")
return(0); //all set up anyhow
}
else
{
ResetPrevTarget();
m_LastNode = tn;
}
}
else //is the first
{
ResetPrevTarget(); //just in case
m_LastNode = tn; //save current node
}
//Drag is now over a new node with new capabilities
CShItem CSI = tn.Tag as CShItem;
if (CSI.IsDropTarget)
{
m_LastTarget = CSI.GetDropTargetOf(m_View) as ShellDll.IDropTarget;
if (m_LastTarget != null)
{
pdwEffect = m_Original_Effect;
//ShowCnt("Prior to LT.DragEnter")
int res = m_LastTarget.DragEnter(m_DragDataObj, grfKeyState, pt, ref pdwEffect);
if (res == 0)
{
//ShowCnt("Prior to LT.DragOver")
res = m_LastTarget.DragOver(grfKeyState, pt, ref pdwEffect);
//ShowCnt("After LT.DragOver")
}
if (res != 0)
{
Marshal.ThrowExceptionForHR(res);
}
}
else
{
pdwEffect = 0; //couldn't get IDropTarget, so report effect None
}
}
else
{
pdwEffect = 0; //CSI not a drop target, so report effect None
}
if (ShDragOverEvent != null)
{
ShDragOverEvent(tn, ptClient, grfKeyState, pdwEffect);
}
}
return(0);
}
