无法枚举CodeBehind中的控件

Question

I have defined html table not with the asp-tags one in my *.aspx page. Then I have added some asp controls into this table in its rows as: <asp:CheckBox> .

I have defined a lot of checkboxes, because I need to provide for the user large amount of selections and I can't minimize the count of checkboxes.

In CodeBehind I wanted to enumerate the whole Controls to find, what I need by the GetType().Name and then added to temporary list for the future actions.

But I've got a trouble, in the debugger I can't see any checkbox and the amount of the controls is very small.

I'm enumerating the controls in page like this:

foreach (var item in Page.Controls)
{
    if (item.GetType().Name == "CheckBox")
    {
         CheckBox checkBox = item as CheckBox;

         if (checkBox.ID != null && checkBox.ID != String.Empty && checkBox.Checked)
         {
             arrayDocs.Add(checkBox.ID);
         }
    }
}

The full code of my page:

aspx: http://pastebin.com/gUs2LchL

code behind: http://pastebin.com/5tfnKJSt

Answer 1

As per MSDN the Control.Controls property returns a collection of the child controls of that control, and not descendants . Only server side controls directly contained within that control will be part of the collection.

If you want to build a collection of all the controls on the page you will need to recursively loop through the controls to add their child controls and so on - as Magnus correctly stated.

The most efficient/performant way would be to build the collection from the parent container of the checkboxes, in this case the cells of HtmlTable "tableDocs".

Change-

foreach (var item in Page.Controls)

To-

foreach (var item in tableDocs.Controls)

Then you will need to recursively loop through the child controls to at least two levels (row -> cells -> checkboxes) before you get to the checkboxes.

What may be far more straightforward is to use generics and create a typed List of CheckBox containing all the checkboxes you wish to test.

Something like-

var checkboxes = new List<CheckBox>{checkboxAuctionHistory, checkboxBackSaldo, checkboxBalanceDecrypted}; //And so on

    foreach (var checkbox in checkboxes)
    {
        if (!string.IsNullOrWhiteSpace(checkbox.ID) && checkbox.Checked)
            {
                arrayDocs.Add(checkbox.ID);
            }
        }
    } 

This has an obvious flaw in that you need to remember to alter the list every time you add a new checkbox to the form.

Alternatively move the checkboxes out of a table or remove the runat="server" attribute from it, removing the table from the ASP.NET control tree, and making the container for the checkboxes "form1".

Most of the other markup on the page does not have runat="server" and therefore these elements are not part of the ASP.NET control tree.