How can I pass the values false or true of a bool, to another form, and from the form, overwrite the bool values in my main form

Question

I want to overwrite my bool values in my main form, from another from, I have a button with the action click, this one opens a form, well with this button I want to overwrite a bool of my main form

I already wrote this at the body of the action click: this.bool = true; but, nothing happens

Pd: Im a new one at programing

This is part of my code:

public bool ver1;
public bool reg1;

public void bntReg2_Click(object sender, EventArgs e)
{
frmRegistrar registrar = new frmRegistrar();
ver1 = true;
reg1 = true;
this.Hide();
registrar.ShowDialog();
this.Show();
}

Answer 1

Best way to do this is with an event. For example, in this case a child form is Form2 with a button and checkbox.

using System;  
using System.Windows.Forms;  
  
namespace FormToForm  
{  
    public partial class Form2 : Form  
    {  
        public delegate void OnPassData(bool value);  
        public event OnPassData PassEvent;  
        public Form2()  
        {  
            InitializeComponent();  
        }  
  
        private void button1_Click(object sender, EventArgs e)  
        {  
            PassEvent?.Invoke(checkBox1.Checked);  
        }  
    }  
}  
  

Main form, Form1 has a button and checkbox. We create an instance of Form2 and subscribe to the custom event.

using System;  
using System.Windows.Forms;  
  
namespace FormToForm  
{  
    public partial class Form1 : Form  
    {  
        public bool SomeBool { get; set; }  
        public Form1()  
        {  
            InitializeComponent();  
        }  
  
        private void button1_Click(object sender, EventArgs e)  
        {  
            var f = new Form2();  
            f.PassEvent += OnPassEvent;  
            f.ShowDialog();  
            f.Dispose();  
        }  
  
        private void OnPassEvent(bool value)  
        {  
            checkBox1.Checked = value;  
            SomeBool = value;  
        }  
    }  
}  
  

Full source

If you want to pass a value from the main form to the child form here is how

using System;  
using System.Windows.Forms;  
  
namespace FormToForm  
{  
    public partial class Form2 : Form  
    {  
        private readonly bool _someBool;  
  
        public delegate void OnPassData(bool value);  
        public event OnPassData PassEvent;  
        public Form2()  
        {  
            InitializeComponent();  
        }  
  
        public Form2(bool someBool)  
        {  
            InitializeComponent();  
            _someBool = someBool;  
            checkBox1.Checked = _someBool;  
        }  
  
        private void button1_Click(object sender, EventArgs e)  
        {  
            PassEvent?.Invoke(checkBox1.Checked);  
        }  
    }  
}  
  

Main form

using System;  
using System.Windows.Forms;  
  
namespace FormToForm  
{  
    public partial class Form1 : Form  
    {  
        public bool SomeBool { get; set; }  
        public Form1()  
        {  
            InitializeComponent();  
        }  
  
        private void button1_Click(object sender, EventArgs e)  
        {  
            var f = new Form2(checkBox1.Checked);  
            f.PassEvent += OnPassEvent;  
            f.ShowDialog();  
            f.Dispose();  
        }  
  
        private void OnPassEvent(bool value)  
        {  
            checkBox1.Checked = value;  
            SomeBool = value;  
        }  
    }  
}