If you are selecting only one cell then get selected cell content like this
var cellInfo = dataGrid1.SelectedCells[0];
var content = cellInfo.Column.GetCellContent(cellInfo.Item);
Here content will be your selected cells value
And if you are selecting multiple cells then you can do it like this
var cellInfos = dataGrid1.SelectedCells;
var list1 = new List<string>();
foreach (DataGridCellInfo cellInfo in cellInfos)
{
if (cellInfo.IsValid)
{
//GetCellContent returns FrameworkElement
var content= cellInfo.Column.GetCellContent(cellInfo.Item);
//Need to add the extra lines of code below to get desired output
//get the datacontext from FrameworkElement and typecast to DataRowView
var row = (DataRowView)content.DataContext;
//ItemArray returns an object array with single element
object[] obj = row.Row.ItemArray;
//store the obj array in a list or Arraylist for later use
list1.Add(obj[0].ToString());
}
}