Using FindControl() to find control

Question

I have a Literal control that I am trying to locate so I can insert text into it. I have a Master page that contains several content placeholders.

Answer 1

The ASP ContentPlaceHolder control is a "naming container" (it implements the INamingContainer interface). The Control.FindControls method only searches within the current naming container for a control with the ID that you specify.

I've occassionally included a utility function that accepts a "/" delimited string to arbitrarily navigate through the naming containers on a page. Something like the following implementation. (Note: I have not tried to compile or test this code)

    public static Control FindControlByPath(this Control start, string controlPath)
    {
        if(controlPath == null)
            throw new ArgumentNullException("controlPath");

        string[] controlIds = controlPath.split('/');

        Control current = start;
        if(controlIds[0] == "") // in case the control path starts with "/"
            current = start.Page; // in that case, start at the top

        for(int i=0; i//", if desired
                    break;

                case ".":
                    // do nothing, stay on the current control
                    break;

                case "..":
                    // navigate up to the next naming container
                    current = current.Parent;
                    if(current == null)
                        throw new ArgumentOutOfRangeException("No parent naming container exists.", "controlPath");

                    while(!(current is INamingContainer))
                    {
                        current = current.Parent;
                        if(current == null)
                            throw new ArgumentOutOfRangeException("No parent naming container exists.", "controlPath");
                    }                       
                    break;

                default:
                    current = current.FindControl(controlIds[i]);
                    break;
            }
        }

        return current;
    }

So, in your case you should be able to do the following:

.FindControlByPath("/MainLinks/litNavLinks").Text = sb.ToString();

or

Page.FindControlByPath("MainLinks/litNavLinks").Text = sb.ToString();