private void DataGrid_MouseMove(object sender, MouseEventArgs e)
{
if (e.LeftButton == MouseButtonState.Pressed)
{
DataGridRow row = UIHelper.FindVisualParent <DataGridRow>(e.OriginalSource as FrameworkElement);
if (row != null && row.IsSelected)
{
_source = UIHelper.FindVisualParent <DataGrid>(row).ItemsSource;
_itemToMove = row.Item;
DragDropEffects finalEffects = DragDrop.DoDragDrop(row, _itemToMove, AllowedEffects);
DataGridDragDropEventArgs args = new DataGridDragDropEventArgs()
{
Destination = _destination,
Direction = _direction,
DroppedObject = _itemToMove,
Effects = finalEffects,
Source = _source,
TargetObject = _dropTarget
};
if (_dropTarget != null && Command != null && Command.CanExecute(args))
{
Command.Execute(args);
_itemToMove = null;
_dropTarget = null;
_source = null;
_destination = null;
_direction = DataGridDragDropDirection.Indeterminate;
_lastIndex = -1;
}
}
}
}
private void DataGrid_CheckDropTarget(object sender, DragEventArgs e)
{
var row = UIHelper.FindVisualParent <DataGridRow>(DropTarget ?? e.OriginalSource as UIElement);
if (row == null)
{
// Not over a DataGridRow
e.Effects = DragDropEffects.None;
}
else
{
var curIndex = row.GetIndex();
_direction = curIndex > _lastIndex ? DataGridDragDropDirection.Down : (curIndex < _lastIndex ? DataGridDragDropDirection.Up : _direction);
_lastIndex = curIndex;
e.Effects = ((e.AllowedEffects & DragDropEffects.Copy) == DragDropEffects.Copy) && (e.KeyStates & DragDropKeyStates.ControlKey) == DragDropKeyStates.ControlKey ? DragDropEffects.Copy : DragDropEffects.Move;
}
e.Handled = true;
}
private void DataGrid_Drop(object sender, DragEventArgs e)
{
e.Effects = DragDropEffects.None;
e.Handled = true;
// Verify that this is a valid drop and then store the drop target
var row = UIHelper.FindVisualParent <DataGridRow>(e.OriginalSource as UIElement);
if (row != null)
{
_destination = UIHelper.FindVisualParent <DataGrid>(row).ItemsSource;
_dropTarget = row.Item;
if (_dropTarget != null)
{
e.Effects = ((e.AllowedEffects & DragDropEffects.Copy) == DragDropEffects.Copy) && (e.KeyStates & DragDropKeyStates.ControlKey) == DragDropKeyStates.ControlKey ? DragDropEffects.Copy : DragDropEffects.Move;
}
var item = e.Data.GetData("data");
var args = new DataGridDragDropEventArgs
{
Destination = _destination,
Direction = _direction,
DroppedObject = item,
Effects = e.Effects,
Source = _source,
TargetObject = _dropTarget
};
if (_dropTarget != null &&
Command != null &&
Command.CanExecute(args))
{
Command.Execute(args);
_dropTarget = null;
_source = null;
_destination = null;
_direction = DataGridDragDropDirection.Indeterminate;
_lastIndex = -1;
}
}
}