WPF DataGridComboboxColumn selction fails if Drag&Drop is used

Question

I've got a Usercontrol with TabControl including Datagrid for each tabItem. The Datagrid has 3 Columns, one as a combobox column.
Now I've implemented some Drag&Drop function for moving rows using PreviewMouseLeftButtonDown and Drop event. With that the Drag&Drop
is working fine. But I can't select from the combobox any more, the box opens and I can see the content but if I want to select an Item with the mouse it's selecting the datagridrow beneath the selectedItem of dropdown list. With the up/down key from the keyboard
I can select.
private void ConfigurationFileView_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
DependencyObject source = e.OriginalSource as DependencyObject;
while (source != null && !(source is System.Windows.Controls.ComboBox))
source = VisualTreeHelper.GetParent(source);
if (source != null)
// don't know what to do here....
else
DataGrid dataGrid = (DataGrid)sender;
rowIndex = GetCurrentRowIndex(dataGrid, e.GetPosition);
if (rowIndex < 0)
return;
dataGrid.SelectedIndex = rowIndex;
ParameterVM selectedEmp = dataGrid.Items[rowIndex] as ParameterVM;
if (selectedEmp == null)
return;
DragDropEffects dragdropeffects = DragDropEffects.Move;
if (DragDrop.DoDragDrop(dataGrid, selectedEmp, dragdropeffects) != DragDropEffects.None)
dataGrid.SelectedItem = selectedEmp;
private void ConfigurationFileView_Drop(object sender, DragEventArgs e)
DataGrid dataGrid = (DataGrid)sender;
int index = this.GetCurrentRowIndex(dataGrid, e.GetPosition);
if (index < 0)
return;
if (rowIndex < 0)
ParameterVM newParameter = e.Data.GetData(typeof(ParameterVM))as ParameterVM;
if (null == newParameter)
return;
ObservableCollection<ParameterVM> parameters = dataGrid.ItemsSource as ObservableCollection<ParameterVM>;
if (!parameters.Any(p => p.Name == newParameter.Name && p.Type == newParameter.Type))
parameters.Insert(index, newParameter);
else
if (index == rowIndex)
return;
if (index == dataGrid.Items.Count - 1)
MessageBox.Show("This row-index cannot be drop");
return;
ObservableCollection<ParameterVM> parameters = dataGrid.ItemsSource as ObservableCollection<ParameterVM>;
ParameterVM changedParameter = parameters[rowIndex];
parameters.Move(rowIndex, index);

Answer 1

Drag and drop within a datagrid is rather an unusual thing to do.
I would suggest your problem lies in choosing to do something which will cause complications.
Hope that helps.
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