将wpf datagrid滚动到特定行并聚焦该行

Question

My requirement is to scroll through wpf data grid and reach to particular row and focus that row

I am using the below code to achieve it . Scrolling to particular row is working smoothly but few times focus not work

  private void FocusNextRow()
  {
             int index = indexOfRowsToHighlight[indexOfRowToFocus];
             MessagesDataGrid.SelectedItem = MessagesDataGrid.Items[index];
             MessagesDataGrid.ScrollIntoView(MessagesDataGrid.SelectedItem);
             Thread.Sleep(200);
             MessagesDataGrid.SelectionUnit = DataGridSelectionUnit.FullRow;
             DataGridRow row = MessagesDataGrid.ItemContainerGenerator.ContainerFromIndex(index)  as DataGridRow;
             DataGridCell cell = GetCell(MessagesDataGrid, row, 0);
             cell.Focus();
   }
   private static DataGridCell GetCell(DataGrid dataGrid, DataGridRow rowContainer, int column)
   {
        if (rowContainer != null)
        {
              DataGridCellsPresenter presenter = FindVisualChild<DataGridCellsPresenter>(rowContainer);              
              // try to get the cell but it may possibly be virtualized
              DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
              if (cell == null)
              {                                  
                  cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
              }
               return cell;
            }

             return null;
        }

        private static T FindVisualChild<T>(DependencyObject obj) where T : DependencyObject
        {
           for(int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
           {
               DependencyObject child = VisualTreeHelper.GetChild(obj, i);
               if (child != null && child is T)
                      return (T)child;
               else
               {
                     T childOfChild = FindVisualChild<T>(child);
                      if (childOfChild != null)
                           return childOfChild;
               }
            }
                    return null;
        }

Out of 100 times 90 times focus is working but few times randomly it does not work

Answer 1

it's maybe virtualizing!! when call FocusNextRow function, check status of ItemContainerGenerator

MessagesDataGrid.ItemContainerGenerator.ContainerFromIndex(index)  as DataGridRow;

https://docs.microsoft.com/ko-kr/dotnet/api/system.windows.controls.itemcontainergenerator?view=netframework-4.8

Answer 2

I find two solution for this problem 1. Disable row virtualization property of data grid . But its seriously going to impact the performance. 2. Check whether FindVisualChild() ables to find the row container or not , if not then in that scenario calls rowcontainer.ApplyTemplate() method , this method ApplyTemplate() ensures your row is created in the visual tree. its more efficient way of doing