private void DGV_DragOver(object sender, DragEventArgs e)
{
var pt = DGV.PointToClient(new Point(e.X, e.Y));
var ht = DGV.HitTest(pt.X, pt.Y);
if ((0 <= ht.RowIndex) && (e.Data.GetData(typeof(DownloadRow)) is DownloadRow row) && (row.GetVisibleIndex() != ht.RowIndex))
{
e.Effect = e.AllowedEffect;
if (_DragOver_RowIndex != ht.RowIndex)
{
_DragOver_RowIndex = ht.RowIndex;
DGV.Invalidate();
}
ScrollIfNeed(in pt);
return;
}
e.Effect = DragDropEffects.None;
if (_DragOver_RowIndex.HasValue)
{
_DragOver_RowIndex = null;
DGV.Invalidate();
}
ScrollIfNeed(in pt);
}
private void DGV_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button != MouseButtons.Left)
{
return;
}
var row = GetSelectedDownloadRow();
if (row == null)
{
return;
}
var ht = DGV.HitTest(e.X, e.Y);
if ((ht.RowIndex < 0) || (ht.ColumnIndex < 0))
{
return;
}
if (_DGV_MouseDown_HitTestInfo.Type != DataGridViewHitTestType.Cell)
{
return;
}
const int MOVE_DELTA = 5;
if (Math.Abs(_DGV_MouseDown_ButtonLeft_Location.X - e.X) < MOVE_DELTA &&
Math.Abs(_DGV_MouseDown_ButtonLeft_Location.Y - e.Y) < MOVE_DELTA)
{
return;
}
//-----------------------------------------------------//
_DragOver_RowIndex = null;
DGV.AllowDrop = true;
DGV.DragOver += DGV_DragOver;
DGV.DragDrop += DGV_DragDrop;
DGV.CellPainting += DGV_DragDrop_CellPainting;
try
{
var dragDropEffect = DGV.DoDragDrop(row, DragDropEffects.Move);
if (dragDropEffect == DragDropEffects.Move)
{
SelectDownloadRow(row);
}
else
{
DGV.Invalidate();
}
}
finally
{
DGV.DragOver -= DGV_DragOver;
DGV.DragDrop -= DGV_DragDrop;
DGV.CellPainting -= DGV_DragDrop_CellPainting;
DGV.AllowDrop = false;
}
}
private void DGV_Scroll(object sender, ScrollEventArgs e)
{
DGV.Invalidate();
}
private void Model_CollectionChanged(_CollectionChangedTypeEnum_ collectionChangedType)
{
switch (collectionChangedType)
{
case _CollectionChangedTypeEnum_.Sort:
DGV.Refresh();
break;
case _CollectionChangedTypeEnum_.Add:
{
var v = _UserMade_DGV_SelectionChanged;
DGV.RowCount = _Model.RowsCount;
RestoreSortIfNeed();
if (v != _UserMade_DGV_SelectionChanged)
{
_UserMade_DGV_SelectionChanged = false;
}
_CommonUpdateTimer.Enabled = true;
}
break;
case _CollectionChangedTypeEnum_.Remove:
case _CollectionChangedTypeEnum_.Clear:
case _CollectionChangedTypeEnum_.BulkUpdate:
{
#region [.save selected row.]
var selectedVisibleIndex = (DGV.SelectedRows.Cast <DataGridViewRow>().FirstOrDefault()?.Index).GetValueOrDefault(-1);
#endregion
DGV.CellValueNeeded -= DGV_CellValueNeeded;
DGV.CellFormatting -= DGV_CellFormatting;
DGV.SelectionChanged -= DGV_SelectionChanged;
DGV.CellPainting -= DGV_CellPainting;
try
{
DGV.RowCount = _Model.RowsCount;
RestoreSortIfNeed();
}
finally
{
DGV.CellValueNeeded += DGV_CellValueNeeded;
DGV.CellFormatting += DGV_CellFormatting;
DGV.SelectionChanged += DGV_SelectionChanged;
DGV.CellPainting += DGV_CellPainting;
}
#region [.restore selected row.]
try
{
var hasRows = (0 < DGV.RowCount);
_CommonUpdateTimer.Enabled = hasRows;
if (hasRows)
{
var visibleIndex = Math.Min(Math.Max(0, selectedVisibleIndex), DGV.RowCount - 1);
var dtrow = DGV.Rows[visibleIndex];
if (dtrow.Selected)
{
var row = _Model[visibleIndex];
SelectionChanged?.Invoke(row);
}
else
{
dtrow.Selected = true;
}
}
else
{
SelectionChanged?.Invoke(null);
}
}
catch (Exception ex)
{
Debug.WriteLine(ex);
}
#endregion
DGV.Invalidate();
}
break;
}
}
