C# - Clear all form fields at once

Question

I have a form with several Textbox, Combobox, Radiobutton. And I would like to clear all fields at once. I’ve seen a lot of forums, but I haven’t found what could be my mistake. When I compile it does not return any error and runs normally and when I click to clear the fields I filled does not happen anything. I created the method in the class and in the Button Click event I called it.

Na I tried to put the method in the same place where the event is Click and instantiating so: ClearForm(this.Control); But nothing happens either.

Code in class:

    public class Interface
    {
        public void ClearForm(System.Windows.Forms.Control parent)
        {

            foreach (System.Windows.Forms.Control ctrControl in parent.Controls)
            {
                if (Object.ReferenceEquals(ctrControl.GetType(), typeof(System.Windows.Forms.TextBox)))
                {
                    ((System.Windows.Forms.TextBox)ctrControl).Text = string.Empty;
                }

                else if (object.ReferenceEquals(ctrControl.GetType(), typeof(System.Windows.Forms.ComboBox)))
                {
                    ((System.Windows.Forms.ComboBox)ctrControl).SelectedIndex = -1;
                }

                else if (object.ReferenceEquals(ctrControl.GetType(), typeof(System.Windows.Forms.RadioButton)))
                {
                    ((System.Windows.Forms.RadioButton)ctrControl).Checked = false;
                }
            }
        }
    }
}

In the Button Click event:

        private void btnClear_Click(object sender, EventArgs e)
        {
            Interface inter = new Interface();
            inter.ClearForm(this);
        }

Answer 1

This is the method I use, is already recursive and will clear all screen controls:

public static void ClearControl(Control ctrl)
{
    foreach (Control c in ctrl.Controls)
    {
        if (c is TextBox)
        {
            ((TextBox)c).Text = "";
        }
        else if (c is RichTextBox)
        {
            ((RichTextBox)c).Text = "";
        }
        else if (c is ComboBox)
        {
            ((ComboBox)c).SelectedIndex = -1;
        }
        else if (c is CheckBox)
        {
            ((CheckBox)c).Checked = false;
        }
        else if (c is RadioButton)
        {
            ((RadioButton)c).Checked = false;
        }
        else if (c is DateTimePicker)
        {
            ((DateTimePicker)c).MinDate = new DateTime(1900, 1, 1);
            ((DateTimePicker)c).MaxDate = new DateTime(2100, 1, 1);
            ((DateTimePicker)c).Value = DateTime.Now.Date < ((DateTimePicker)c).MinDate ? ((DateTimePicker)c).MinDate : DateTime.Now.Date > ((DateTimePicker)c).MaxDate ? ((DateTimePicker)c).MaxDate : DateTime.Now.Date;
            if (((DateTimePicker)c).ShowCheckBox)
                ((DateTimePicker)c).Checked = false;
        }
        else if (c is NumericUpDown)
        {
            ((NumericUpDown)c).Value = 0 < ((NumericUpDown)c).Minimum ? ((NumericUpDown)c).Minimum : 0 > ((NumericUpDown)c).Maximum ? ((NumericUpDown)c).Maximum : 0;// ((NumericUpDown)c).Minimum;
        }
        else if (c is PictureBox)
        {
            ((PictureBox)c).Image = null;
        }
        else if (c is MaskedTextBox)
        {
            ((MaskedTextBox)c).Text = "";
        }
        else if (c is Label)
        {
            //((Label)c).Text = "";
        }
        else if (c is DataGridView)
        {
            ((DataGridView)c).DataSource = null;
        }
        else if (c is TrackBar)
            ((TrackBar)c).Value = ((TrackBar)c).Minimum;
        else if (c is RichTextBoxExtended)
            ((RichTextBoxExtended)c).ResetText();
        else if (c.HasChildren)
        {
            if (c is TabControl)
                ((TabControl)c).SelectedIndex = 0;

            ClearControl(c);
        }
    }
}

To call it, from within a Form, just do:

ClearControl(this);

I changed some things I use, which are specific to my environment, but you can change as you prefer.