Loop through Textboxes

Question

I have a winforms app that has 37 textboxes on the screen. Each one is sequentially numbered:

DateTextBox0
DateTextBox1 ...
DateTextBox37

I am trying to iterate through the text boxes and assign a value to each one:

int month = MonthYearPicker.Value.Month;
int year = MonthYearPicker.Value.Year;
int numberOfDays = DateTime.DaysInMonth(year, month);

m_MonthStartDate = new DateTime(year, month, 1);
m_MonthEndDate = new DateTime(year, month, numberOfDays);

DayOfWeek monthStartDayOfWeek = m_MonthStartDate.DayOfWeek;
int daysOffset = Math.Abs(DayOfWeek.Sunday - monthStartDayOfWeek);

for (int i = 0; i <= (numberOfDays - 1); i++)
{
 //Here is where I want to loop through the textboxes and assign values based on the 'i' value
   DateTextBox(daysOffset + i) = m_MonthStartDate.AddDays(i).Day.ToString();
}

Let me clarify that these textboxes appear on separate panels (37 of them). So in order for me to loop through using a foreach, I have to loop through the primary controls (the panels), then loop through the controls on the panels. It starts getting complicated.

Any suggestions on how I can assign this value to the textbox?

Solution 1

To get all controls and sub-controls recursively of specified type, use this extension method:

public static IEnumerable<TControl> GetChildControls<TControl>(this Control control) where TControl : Control
{
    var children = (control.Controls != null) ? control.Controls.OfType<TControl>() : Enumerable.Empty<TControl>();
    return children.SelectMany(c => GetChildControls<TControl>(c)).Concat(children);
}

usage:

var allTextBoxes = this.GetChildControls<TextBox>();
foreach (TextBox tb in allTextBoxes)
{
    tb.Text = ...;
}

Solution 2

You Could loop all the controls in the form asking one by one if it is a "Textbox" y ther return the complete List of them.

public List GetTextBoxes(){   
    var textBoxes = new List();   
        foreach (Control c in Controls){   
            if(c is TextBox){   
                textBoxes.add(c);   
        }   
    }   
return textBoxes;   
}

Solution 3

Since this post seems to resurrect itself from time to time and since the solutions above do not find controls inside of controls, such as in a groupbox, this will find them. Just add your control type:

    public static IList<T> GetAllControls<T>(Control control) where T : Control
    {
        var lst = new List<T>();
        foreach (Control item in control.Controls)
        {
            var ctr = item as T;
            if (ctr != null)
                lst.Add(ctr);
            else
                lst.AddRange(GetAllControls<T>(item));

        }
        return lst;
    }

And it's use:

        var listBoxes = GetAllControls<ListBox>(this);
        foreach (ListBox lst in listBoxes)
        {
            //Do Something
        }

Solution 4

You can loop through the textboxes in your form in a fairly simple manner:

Func<ControlCollection, List<TextBox>> SearchTextBoxes = null;
SearchTextBoxes = coll => {
    List<TextBox> textBoxes = new List<TextBox>();

    foreach (Control c in coll) {
        TextBox box = c as TextBox;
        if (box != null)
           textBoxes.Add(box);
        if (c.Controls.Count > 0)
           textBoxes.AddRange(SearchTextBoxes(c.Controls));
    }

    return textBoxes;
};

var tbs = SearchTextBoxes(this.Controls).OrderBy(tb => tb.Name);

Edit: Changed according to new requirements. Not nearly as elegant as the LINQ-solution, of course :)

Solution 5

Iterate through controls within form and check name of the control if matched then set Text property as you require.

int i = 0;
foreach (Control contrl in this.Controls) {
    if (contrl.Name == ("DateTextBox" + i.ToString())) {
        contrl.Text = "requiredtexttobeset";
    }
    i = i + 1;
}

View more solutions

Comments

[Fredrik Mörk]

That will miss any controls that are not located directly on the form (such as in a panel, tab page or similar).

[Taryn]

I know I can loop through the controls but this screen contains 37 panels with the DateTextBoxes as well as another control. So in order for me to get the data I have to loop through the panel controls and then the controls in the panel to get an array. Is there a way for me to do this without using an array? Just assign the DateTextBoxes the data it needs?

[abatishchev]

@bluefeet: See my answer to find how to loop through nested controls

[Christian]

Well, having them in panels changes things "a bit". You need to go recursive about it. Or even better, use the answer that abatishchev provided. It's pretty neat :)

[Fredrik Mörk]

+1 - that is almost exactly the code that I was about to post.

[HelpNeeder]

what if there might be additional text box which name happens to be fingering other than datatexrboc? will that count all text hides including one we don't need to count?

[B. Clay Shannon-B. Crow Raven]

Don't you mean "foreach (TextBox tb in allTextBoxes)" for the loopiness?

[kiltek]

Seems like the most elegant solution, but i get the error: "TControl ---> The type or namespace name 'TControl' could not be found (are you missing a using directive or an assembly reference?) ". I searched MSDN, but didnt find that class. What to do?

[abatishchev]

@kiltek: this is the generic parameter declared as where TControl : System.Web.Ui.Control iirc.

[TEK]

I'm getting the error "Constraints are not allowed on non-generic declarations" (.net 4.0)

[abatishchev]

@TEK: Right! Don't know how I missed it and nobody noticed for so long time. Fixed. Thanks!

[TEK]

@abatishchev Wow. That has to be the fastest edit of all time. Thank you! (Ignore my previous comment, I am dumb).

[abatishchev]

@TEK: Yea, me is getting this error, too. And I'm applied the fix, please check it out. I'm just was digging into my very old code to figure out how this code being copy-pasted was working before. Hm. weird. Anyway, now should work. Let me know if it doesn't, please.

[TEK]

@abatishchev In it's current state, it works great! Thank you kindly for the extremely rapid response to a 4+ year old post. This has saved me having to do it the old dumb way.

[B. Clay Shannon-B. Crow Raven]

Oddly enough, this works dandy except for a combobox that is populated with string values; in that case, the loop to set its SelectedIndex to -1 doesn't work. I have to set it explicitly after the loop for it to work. Why this would be, I don't know, but here is my code: var allComboBoxes = this.GetChildControls<ComboBox>(); foreach (ComboBox cmbx in allComboBoxes) { cmbx.SelectedIndex = -1; } comboBoxDaysOfMonth.SelectedIndex = -1;

[B. Clay Shannon-B. Crow Raven]

On third thought, this is happening to all the controls that are not directly on the form (those on a Panel or a Groupbox); I think that's probably the real issue/the crux of the biscuit.

[n00dles]

I don't get how this gets ALL textboxes. For me, it only gets textboxes that are direct children of the form/given control. You still need to loop through each control with this solution, right?

[abatishchev]

@n00dles: the method calls itself recursively on all children of given type. Another option would be rewrite in and remove OfType<T>. So just return all children aka flatten the hierarchy. Then call OfType<T> to filter by given type.

[n00dles]

I noticed the recursive call. I must have done something wrong then, coz it didn't return child controls. I found another similar method (but not an extension) that worked though. I don't yet understand lambda expressions, so it's hard for me to think it through.

[abatishchev]

@n00dles: post an answer if you found a better (or at least a similar) solution!

[jkulpe]

This worked for me (the top answer didn't). I put my method in a static class and had to set the method signature to " ... GetAllControls<T>(this Control control) ..." for it to work. The "this" would allow an instance of a control to call this extension method.