Answer / aravazhi

Try this query you can avoid InvalidCastException...

string strQry = "update customer set lastname=@LastName
where id=@VarId";
SqlCommand cmd=new SqlCommand(strQry,con);
int varid = (int)DataGrid1.DataKeys[(int)e.Item.ItemIndex];
string LName = ((TextBox)e.Item.FondControl
("txtLName")).Text;//txtLname is ID of control
cmd.Paramters.Add(new SqlParameter("@LastName",LName));
cmd.Paramters.Add(new SqlParameter("@VarId",varid));
cmd.ExecuteNonQuery();
DataGrid1.EditItemIndex=- 1;
DataGrid1.DataBind();

Answer / pk

public void DataGrid1_Update(Object sender,
DataGridCommandEventArgs e)
{

string unitprice =
((TextBox)e.Item.Cells[3].Controls[0]).Text;

string quantity =
((TextBox)e.Item.Cells[4].Controls[0]).Text;

string discount =
((TextBox)e.Item.Cells[5].Controls[0]).Text;

int orderid =
(int)DataGrid1.DataKeys[(int)e.Item.ItemIndex];

string productid =
((TextBox)e.Item.Cells[2].Controls[0]).Text;

try
{

string updateCmd = "UPDATE [Order Details] SET
UnitPrice = @UnitPrice,"

+ "Quantity = @Quantity, Discount = @Discount
where OrderId =@OrderId and ProductId=@ProductId";

SqlConnection cn = new SqlConnection(strConn);

SqlCommand myCommand = new SqlCommand(updateCmd,
cn);

myCommand.Parameters.Add(new
SqlParameter("@UnitPrice", Convert.ToDecimal(unitprice)));

myCommand.Parameters.Add(new
SqlParameter("@Quantity", Convert.ToInt16(quantity)));

myCommand.Parameters.Add(new
SqlParameter("@Discount", Convert.ToInt16(discount)));

myCommand.Parameters.Add(new
SqlParameter("@OrderId", orderid));

myCommand.Parameters.Add(new
SqlParameter("@ProductId", Convert.ToInt16(productid)));

cn.Open();

myCommand.ExecuteNonQuery();

DataGrid1.EditItemIndex = -1;

BindGrid();

}

catch (Exception ex)
{

lblError.Visible = true;

lblError.Text = (ex.Message);

}

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