Loop through all controls of a Form, even those in GroupBoxes

Question

I\'d like to add an event to all TextBoxes on my Form:

foreach (Control C in this.Controls)
{
    if (C.GetType() == typeof(System.Windows.Forms         


        

Answer 1

I know that this is an older topic, but would say the code snippet from http://backstreet.ch/coding/code-snippets/mit-c-rekursiv-durch-form-controls-loopen/ is a clever solution for this problem.

It uses an extension method for ControlCollection.

public static void ApplyToAll(this Control.ControlCollection controlCollection, string tagFilter, Action action)
{
    foreach (Control control in controlCollection)
    {
        if (!string.IsNullOrEmpty(tagFilter))
        {
            if (control.Tag == null)
            {
                control.Tag = "";
            }

            if (!string.IsNullOrEmpty(tagFilter) && control.Tag.ToString() == tagFilter && control is T)
            {
                action(control);
            }
        }
        else
        {
            if (control is T)
            {
                action(control);
            }
        }

        if (control.Controls != null && control.Controls.Count > 0)
        {
            ApplyToAll(control.Controls, tagFilter, action);
        }
    }
}

Now, to assign an event to all the TextBox controls you can write a statement like (where 'this' is the form):

this.Controls.ApplyToAll("", control =>
{
    control.TextChanged += SomeEvent
});

Optionally you can filter the controls by their tags.