Looping through tabpages of tabcontrol in c#

Question

I am trying to Loop through the tabpages of a tabcontrol in c#. Each tabpage has multiple textboxes. The purpose is to sum up all of the values of these textboxes.

double sum = 0;
foreach(TabPage tbp in tabControl1.TabPages)
{
    foreach(System.Windows.Forms.Control c in tbp.Controls)
    {
            if (c.ToString() == "TextBox")
            {
                sum += Convert.ToDouble(c.Text);
            }
        }
    }

When I execute this code, the first foreach loop is entered three times even though I have one TabPage in my TabControl. Furthermore, the if statement is not entered, so there seems to be something wrong with that as well.

did you try using breakpoints and looking at what its doing? — slow, Apr 12 '18 at 06:58
This should work, so USE the DEBUGGER !! - Also it won't get textboxes which are nested deeper, e.g. in panels or groupboxes.. Then you could go for a recursive function. — TaW, Apr 12 '18 at 08:18
Whoops, this `if (c.ToString() == "TextBox")` is nonsense. It could be written as `if (c is TextBox)`. But why you loop 3 times over one page must be checked with the debugger!! ((And of course the debugger would have told you what c.ToString actuall looks like..)) — TaW, Apr 12 '18 at 10:10

score 0 · Answer 1 · answered Apr 13 '18 at 07:08

This code (C#7) allows you to safety sum all text boxes values in a tab control, include text boxes nested in children container controls (example: a text box in panel, and the panel in a tab page)

    private double SumTextBoxesValues()
    {
        double sum = 0;
        foreach (TabPage tbp in tabControl1.TabPages)
        {
            var textBoxes = GetAllTextBoxes(tbp);

            foreach (var textBox in textBoxes)
            {
                if(double.TryParse(textBox.Text, out double value))
                    sum += value;
            }

        }

        return sum;
    }

    private static IEnumerable<TextBox> GetAllTextBoxes(Control container)
    {
        var controlList = new List<TextBox>();
        foreach (Control c in container.Controls)
        {
            controlList.AddRange(GetAllTextBoxes(c));

            if(c is TextBox box)
                controlList.Add(box);
        }
        return controlList;
    }

Looping through tabpages of tabcontrol in c#

1 Answers1