Question

I think this problem is related to Reference Types, and my lack of understanding of these …

So I have dynamically created ASP.Net Tables (as in Web.UI.WebControls.Table, not the database variety)
These can have anything from one row with one cell with text, to a whole series of nested tables and controls, depending on the clients.

I need to loop through each TableRow, if a certain condition is met then I copy that row to a 2nd Table object. Here’s a simplified bit of the code.

        Table xTblComplete = (passed in as parameter) // original & complete table
        Table xTblTemp = new Table();  // gets built dynamically with specific rows

        foreach (TableRow xThisRow in xTblComplete.Rows)
        { 
            if (xThisRow.Cells.Count > 0)
            {
                if (certain condition met)
                {
                    xTblTemp.Rows.Add(xThisRow);
                }
            }
        }

Where I come unstuck is that the foreach (row in table.rows) throws an error when I try to add the TableRow to Table2. I get the error “Collection was modified; enumeration operation may not execute. ”
This makes sense, in that I should be making a COPY of that Table Row to add.

Can anyone advise on how this is done? I’ve scanned MSDN and the forums for general copying-of-reference types, but they all seem to point to using ICloneable , which I believe I’m unable to do as this isn’t my class.

Am hoping this is something small and fundamental I’m missing out on, thanks in advance.

Answer 1

Thanks Ulises, your answers were helpful, unfortunately the complexity of these tables procluded a simple loop & copy contents. By that I mean that there were cells that might possibly have had 5 levels of nested tables, with any number of web controls inside each. Yep, a CSS perfectionist would retch at the idea of so many nested tables, but it’s what had to be done!!

In the end I utilized a while(bln) loop, examining xTblComplete.Rows[0] each time.

If it met the condition , I would copy it to xTmpTable, which also removed it from xTblComplete.

If it failed the condition, I would remove it myself ( xTblComplete.Rows.Remove(xTblComplete.Rows[0]);

This way Rows[0] would always be the next to process.
After each Loop I checked the bln for more rows to process, if none then the loop would exit.