Validating Form data

Question

I am looking for a better way to verify that no field is left blank in a form, currently this is my implementation, if you have a better one it will be welcomed, note tha I am using KryptonControls.

private bool verify(Control c)
{
    switch (c.GetType().Name)
    {
        case "KryptonTextBox":
            {
                if (((KryptonTextBox)c).Text == "")
                {
                    ((KryptonTextBox)c).StateCommon.Border.Color1 = Color.Red;
                    ((KryptonTextBox)c).GotFocus += new EventHandler(ControlGotFocus);
                    return false;
                }
            }
            break;
        case "KryptonComboBox":
            {
                if (((KryptonComboBox)c).SelectedIndex < 0)
                {
                    ((KryptonComboBox)c).StateCommon.ComboBox.Border.Color1 = Color.Red;
                    ((KryptonComboBox)c).GotFocus += new EventHandler(ControlGotFocus);
                    return false;
                }
            }
            break;
        case "KryptonDataGridView":
            {
                if (((KryptonDataGridView)c).Rows.Count <= 0)
                {
                    ((KryptonDataGridView)c).StateCommon.HeaderColumn.Border.Color1 = Color.Red;
                    ((KryptonDataGridView)c).GotFocus += new EventHandler(ControlGotFocus);
                    return false;
                }
            }
            break;
        default:    
            break;
    }

    if (c.Controls.Count > 0)
    {
        foreach (Control cc in c.Controls)
        {
            if (!verify(cc))
            {
                return false;
            }
        }
    }
    return true;
}

so when the user sets focus to a control that has to be verified this code runs:

void ControlGotFocus(object sender, EventArgs e)
{
    switch (sender.GetType().Name)
    {
        case "KryptonTextBox":
            {
                ((KryptonTextBox)sender).StateCommon.Border.Color1 = Color.Gray;
            }
            break;
        case "KryptonComboBox":
            {
                ((KryptonComboBox)sender).StateCommon.ComboBox.Border.Color1 = Color.Gray;
            }
            break;
        case "KryptonDataGridView":
            {
                ((KryptonDataGridView)sender).StateCommon.HeaderColumn.Border.Color1 = Color.Black;
            }
            break;
        default:
            break;
    }
}

Answer 1

You may optimize code something like this:

switch (c.GetType().Name)  {  case "KryptonTextBox": }

to:

TextBox tb = c as TextBox;
if (tb != null)
    return string.IsNullOrEmpty(tb.Text);

ComboBox cb = c as ComboBox;
if (cb != null)
   return cb.SelectedIndex < 0;

etc.

But I suggest to use validators for these puproses.