//'______________________________________________________________

//'                 C O N T R O L S   C O L L E C T I O N   D E M O

//'                                 Ron Kessler

//'                               Created 9/24/08
//'______________________________________________________________


//'This demo shows how to cycle through the controls collection on a form to clear all testboxes.
//'However, notice there is a textbox inside of a container control (Groupbox). The form's control
//'collection will not see this textbox because it is inside a container control. So we will use the
//'HasChildren property of the controls in the form's collection to find the nested controls!



using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace Controls_Collection_Demo
{
    public partial class frmMain : Form
    {
        public frmMain()
        {
            InitializeComponent();
        }

        private void btnClear_Click(object sender, EventArgs e)
        {
            //---cycle through forms collection and clear textboxes
            foreach (Control myControl in this.Controls)
            {
                    if (myControl is TextBox)
                        myControl.Text = "";
                    else if (myControl.HasChildren)   //if it comes across a groupbox or tab control that has child controls, clear textboxes & radiobuttons in them also
                        {
                            foreach (Control nestedControl in myControl.Controls)
                            {

                                if (nestedControl is TextBox)
                                    nestedControl.Text = "";
                                else if (nestedControl is RadioButton)
                                {
                                    RadioButton myRadioButton = (RadioButton)nestedControl;  //see note below
                                    myRadioButton.Checked = false;
                                }
                            
                            
                            }
                
                
                        }  
            
            
           }
           txtFirst.Focus();
        }
    }

    // 'Note about the RadioButton loop above:
    //'All controls have a text property (I think). But not all controls have a Checked property. So to
    //'uncheck a RadioButton or Checkbox Control, I have to create a new reference variable (myRadioButton) line 52
    //'and assign it to the current control being pointed to in nestedControl. Then I can access its checked
    //'property and uncheck it by making it false in line 53.
}