DataGrid 得到DataGridRow 和DataGridColumn

 /* ----------------------------------------------------------
 文件名称：DataGridPlus.cs

 作者：秦建辉

 MSN：[e-mail]
 QQ：36748897

 博客：http://blog.csdn.net/jhqin

 开发环境：
     Visual Studio V2010
     .NET Framework 4 Client Profile

 版本历史：
     V1.0    2012年06月07日
             WPF DataGrid控件扩展方法

 参考资料：
     http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/b7299e55-92e2-4a6b-8987-869fef8f22eb/
 ------------------------------------------------------------ */
 using System.Windows.Controls;
 using System.Windows.Controls.Primitives;
 using System.Windows.Media;

 namespace Splash.WPF
 {
     public static class DataGridPlus
     {
         /// <summary>
         /// 获取DataGrid控件单元格
         /// </summary>
         /// <param name="dataGrid">DataGrid控件</param>
         /// <param name="rowIndex">单元格所在的行号</param>
         /// <param name="columnIndex">单元格所在的列号</param>
         /// <returns>指定的单元格</returns>
         public static DataGridCell GetCell(this DataGrid dataGrid, int rowIndex, int columnIndex)
         {
             DataGridRow rowContainer = dataGrid.GetRow(rowIndex);
             if (rowContainer != null)
             {
                 DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(rowContainer);
                 DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(columnIndex);
                 if (cell == null)
                 {
                     dataGrid.ScrollIntoView(rowContainer, dataGrid.Columns[columnIndex]);
                     cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(columnIndex);
                 }
                 return cell;
             }
             return null;
         }

         /// <summary>
         /// 获取DataGrid的行
         /// </summary>
         /// <param name="dataGrid">DataGrid控件</param>
         /// <param name="rowIndex">DataGrid行号</param>
         /// <returns>指定的行号</returns>
         public static DataGridRow GetRow(this DataGrid dataGrid, int rowIndex)
         {
             DataGridRow rowContainer = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromIndex(rowIndex);
             if (rowContainer == null)
             {
                 dataGrid.UpdateLayout();
                 dataGrid.ScrollIntoView(dataGrid.Items[rowIndex]);
                 rowContainer = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromIndex(rowIndex);
             }
             return rowContainer;
         }

         /// <summary>
         /// 获取父可视对象中第一个指定类型的子可视对象
         /// </summary>
         /// <typeparam name="T">可视对象类型</typeparam>
         /// <param name="parent">父可视对象</param>
         /// <returns>第一个指定类型的子可视对象</returns>
         public static T GetVisualChild<T>(Visual parent) where T : Visual
         {
             T child = default(T);
             int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
             for (int i = ; i < numVisuals; i++)
             {
                 Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
                 child = v as T;
                 if (child == null)
                 {
                     child = GetVisualChild<T>(v);
                 }
                 if (child != null)
                 {
                     break;
                 }
             }
             return child;
         }
     }
 }