Having Trouble Using LINQ to Objects on the Controls Collection of a Page

Question

I need to store data from a form for recovery from the session. Below is my rough first attempt for a generalized method for textboxes:

Load Session:

Dictionary<string, string> AppInfo = (Dictionary<string,string>) Session["ApplicantionInfo"];
this.Controls.OfType<TextBox>()
         .ToList<TextBox>()
         .ForEach( x => x.Text = AppInfo[x.ID] );

Save Session:

Session["ApplicationInfo"] = this.Controls.OfType<TextBox>()
                                  .ToList<TextBox>()
                                  .ToDictionary<TextBox,string>(kvp => kvp.ID);

However, it appears that the Controls collection is not working for me. What am I doing wrong?

this.Controls.OfType<TextBox>() yields no results at run time when I do a quick watch on it.

Are any of the TextBox controls contained inside other controls? If so, they won't be found directly in the Controls collection for the page. — mellamokb, Feb 15 '11 at 21:11
Is there any easy way to get an enumeration of controls if the above is true? — Joshua Enfield, Feb 15 '11 at 21:14

score 3 · Accepted Answer · edited May 23 '17 at 11:47

3

See Recursive control search with Linq.

edited May 23 '17 at 11:47

Community

1
1

answered Feb 15 '11 at 21:15

mellamokb

56,094
12
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score 1 · Answer 2 · answered Feb 15 '11 at 21:17

1

This is how I access form controls.

for (int i = 0; i < this.Controls.Count; i++)
{
      this.Controls[i].Visible = false;

 }

answered Feb 15 '11 at 21:17

clamchoda

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score 1 · Answer 3 · answered Feb 15 '11 at 21:17

How about

public static List<Control> GetAllControls(List<Control> controls, Type t, Control parent)
{
            foreach (Control c in parent.Controls)
            {
                if (c.GetType()== t)
                    controls.Add(c);
                if (c.HasControls())
                    controls = GetAllControls(controls, t, c);
            }
            return controls;
}

and call

var allControls = new List<Control>();
GetAllControls(allControls, typeof(TextBox), Page);

Having Trouble Using LINQ to Objects on the Controls Collection of a Page

3 Answers3