C# - Put controls in a loop

Question

I have 30 checkboxes (cb1, cb2,... ,cb30) that I need to be checked programmatically based on a variable value. So, when the var value is 12, I need the checkbox1 to checkbox12 to be .checked = true;

I really have no Idea how to get it work Please help

Thank you

Edit: I tried aghilpro's suggestion but I got errors:

        reader1.Read();
        if (reader1.IsDBNull(0))
        {
            label5.Text = "Nothing yet";
        }
        else
        {
            label5.Text = reader1.GetString(0).ToString() + " Times";
            {
                for (int i = 0; i < reader1.GetInt32(0); i++)
                {
                    Controls["checkBox" + i.ToString()].Checked = True;
                }
            }
        }
        koneksi.Close();

Here's the output:

Error   1   'System.Windows.Forms.Control' does not contain a definition for 'Checked' and no extension method 'Checked' accepting a first argument of type 'System.Windows.Forms.Control' could be found (are you missing a using directive or an assembly reference?)

What have you tried so far? Have a look at the [tour] (https://stackoverflow.com/tour) and [How to Ask](https://stackoverflow.com/help/how-to-ask) — M0ns1f, Sep 23 '17 at 06:31
Yes, but still you will have some html where check box are binding and you will also have method where you need to do this code, so add both for reference.. — Bharat, Sep 23 '17 at 06:32
@jumper0x08 in that case He need to bind at least snapshot of screen.. — Bharat, Sep 23 '17 at 06:38
owhh man.. I have no idea how to post my code in a comment... x_X.. I'm sorry.. — Andre Rio, Sep 23 '17 at 06:42
@AndreRio You can edit your question and add some info..otherwise no one can help you.. — Bharat, Sep 23 '17 at 06:49
Similiar question is answered for making multiple panels visibile/invisible.. check here.. https://stackoverflow.com/questions/46332748/panel-control-with-variable-name/46333052#46333052 — Chetan, Sep 23 '17 at 07:01
@AndreRio : check this, https://stackoverflow.com/questions/14051494/check-all-checkboxes-in-checkboxlist-with-one-click-using-c-sharp — Bharat, Sep 23 '17 at 07:13
Done.. it really solve it.. thx a lot @Bharat... cheers!! :) — Andre Rio, Sep 23 '17 at 07:30

score 1 · Answer 1 · answered Sep 23 '17 at 07:32

1

You need to cast the Control to a CheckBox. Hint: Not all controls have a Checked property. I hope this make sense. One question to ask yourself is the following. What would happen if you had a button called "checkBox9"?

var checkBox = (CheckBox)(Controls["checkBox" + i.ToString()]);
checkBox.Checked = True;

answered Sep 23 '17 at 07:32

vidstige

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1

As described in your answer, I would use (Controls["checkBox" + i.ToString()]) as Checkbox to avoid issues if e.g. a button is named "checkbox9". A null-check is required to handle/ignore the button. – Odrai Sep 23 '17 at 08:19

score 1 · Answer 2 · answered Sep 23 '17 at 08:28

The answer of vidstige is correct, but I would use the 'as' operator.

The 'as' operator is like a cast operation. However, if the conversion isn't possible, 'as' returns null instead of raising an exception.

CheckBox checkBox = (Controls["checkBox" + i.ToString()]) as CheckBox;
if(checkBox != null)
{
   checkBox.Checked = True;
}

C# - Put controls in a loop

2 Answers2