Question

I want to insert productDetail arraylist in products arraylist

ArrayList products = new ArrayList();

ArrayList productDetail = new ArrayList();

   foreach (DataRow myRow in myTable.Rows)
     {
     productDetail.Clear();                      
      productDetail.Add( "CostPrice" + "," + myRow["CostPrice"].ToString());

      products.Insert(myTable.Rows.IndexOf(myRow),(object)productDetail);
     }

But each entery in product list is filled with last productdetails ArrayList.
What wrong I am doing here?

Answer 1

Try moving

ArrayList productDetail = new ArrayList();

inside the foreach loop:

ArrayList products = new ArrayList();
foreach (DataRow myRow in myTable.Rows) {
    ArrayList productDetail = new ArrayList();
    productDetail.Add( "CostPrice" + "," + myRow["CostPrice"].ToString());
    products.Insert(myTable.Rows.IndexOf(myRow),(object)productDetail);
}

The point is that, in your code, you are always adding a reference to the same object: Insert is not making a copy of your list each time…