Field check Combobox, Textbox Maskedtextbox

Question

How to create a method to check that all "Combobox, Textbox Maskedtextbox" fields are filled in? Mine does not work

public bool CampoVazio()
{
    bool ok = false;
    foreach(Control ctrl in this.Controls)
      {
          if(ctrl is TextBox)
            {
              if(string.IsNullOrEmpty(ctrl.Text))
                 {
                    ok= true;
                    break;
                 }
            }
        }
    return ok;
}

Answer 1

Basically you need to validate all fields that are TextBoxBase (this includes all types of TextBox) or ComboBox or if they have "children", in this case, you need to call the function again by passing the control as parameter.

The method returns true if all fields have been duly completed.

private bool VerificaCamposPreenchidos(Control parent = null)
{
    if (parent == null)
        parent = this;

    foreach (Control control in parent.Controls)
    {
        if (control is TextBoxBase)
        {
            var txt = (TextBoxBase)control;
            if (string.IsNullOrEmpty(txt.Text))
                return false;
        }

        if (control is ComboBox)
        {
            var cmb = (ComboBox)control;
            if (cmb.SelectedValue == null)
                return false;
        }

        if (control.HasChildren)
        {
            if (!VerificaCamposPreenchidos(control))
                return false;
        }
    }

    return true;
}

Answer 2

Use a recursive function, so that you go through the control and your children:

    public static bool CamposVazios(Control _ctrl)
    {
        foreach (Control c in _ctrl.Controls)
        {
            if (c is TextBox)
            {
                if (String.IsNullOrEmpty(((TextBox)c).Text))
                    return true;
            }
            else if (c is ComboBox)
            {
                if (((ComboBox)c).SelectedValue == null)
                    return true;
            }
            else if (c.HasChildren)
            {
                if (CamposVazios(c))
                    return true;
            }
        }

        return false;

    }

To call her, inside a Form:

if (CamposVazios(this))
{
  //Há algum campo vazio.
}

Suggestion:

In my case, I put one Exception when the field is empty, because then I can inform the user which field is invalid, highlight the field or anything like that. Ex:

    public static void CamposVazios(Control _ctrl)
    {
        foreach (Control c in _ctrl.Controls)
        {
            if (c.HasChildren)
            {
                CamposVazios(c);
            }
            else if (c is TextBox)
            {
                if (String.IsNullOrEmpty(((TextBox)c).Text))
                {
                    throw new Exception("Campo "+ c.Name + " está vazio");
                }
            }
            else if (c is ComboBox)
            {
                if (((ComboBox)c).SelectedValue == null)
                {
                    throw new Exception("Campo "+ c.Name + " está vazio");
                }
            }
        }
    }

and when calling the function:

try 
{
   CamposVazios(this);
   //Processar / Gravar / etc...
} 
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}