How can I save rearranged column positions when reading out a DataGrid?

Question

I have a DataGrid implemented in a WPF-window inside a VSTO-AddIn, which is supposed to preview data to the user before it is pasted to an existing Excel-sheet. The CanUserSortColumns-Property is set to true, so the user is able to rearrange the columns before they are read out and pasted to the sheet. However, when I read out the DataRows from the DataGrid, as shown below, the columns are back in their original position.

 object[,] dataArray = new object[allRows, allCols];

        for (int r = 0; r < allRows; r++)
        {
            DataRow row = ClientGrid.Rows[r];
            for (int c = 0; c < allCols; c++)
            {
                dataArray[r, c] = row[c];
            }
        }

Here is my question: Is there any way to fix this the quick way or at least to track the changes of column display indices in order to rearrange the column order in the code with every change of the columns display order?

I've already tried working something out with the DisplayIndex-property but I did not quite get the hang of the numbers it spits out.

Answer 1

I ended up doing the following:

1. Reading out the DisplayIndex-Property and the initial position of each column and ordering the tuples by the DisplayIndex-Property afterwards

   var columnIndices = new List<Tuple<int,int>>();
   var colCounter = 0;
   
   foreach (var col in myDataGrid.Columns)
   {
       columnIndices.Add(Tuple.Create(col.DisplayIndex, colCounter));
       colCounter += 1;
   }
   
   var sortedColumns = columnIndices.OrderBy(x => x.Item1).ToList();        
   

2. Creating an empty DataTable and adding the original DataGrid's columns to it. Then I set the new DataTable's DataRow's cells equal to the cells of the DataRows of the original DataGrid.

   var myDataTable = new DataTable();
   
   foreach (var index1 in sortedColumns)
   {
       var columnName = myDataGrid.Columns[index1.Item2].ColumnName;
       myDataTable.Columns.Add(columnName, myDataGrid.Columns[index1.Item2].DataType);
   }
   
   foreach (DataRow dr in myDataGrid.Rows)
   {
       var itemArray = new object[allCols];
       var indexer = 0;
   
       foreach (var index2 in sortedColumns)
       {
           itemArray[indexer] = dr[index2.Item2];
           indexer += 1;
       }
   
       myDataTable.Rows.Add(itemArray);
   }