Save and Reload Data in C sharp forms

Question

I am looking for the solution to save and reload what I enter into my text boxes or what I filled in my ComboBoxes. Here is the code I current have, but I am not 100% sure it is all correct. I am only posting the code I need help with. If you need the entire batch of code I can post it, but I did not think it was relevant to what I am asking for. This is what I have done so far, which I am not sure it will actually save the info that is typed in, and I am completely unsure as to what to put in the loadLastBtn method. I Just want it to be saved to memory even when the textbox texts have changed and then I want to be able to retrieve that from memory when I hit the loatLastbtn.

    private void submitBtn_Click(object sender, EventArgs e)
    {
        List<Members> lstMembers = new List<Members>();
        if (string.IsNullOrEmpty(firstNameTxt.Text) || string.IsNullOrEmpty(lastNameTxt.Text)
           || string.IsNullOrEmpty(userNameTxt.Text) ||
           string.IsNullOrEmpty(passwordTxt.Text) || string.IsNullOrEmpty(confPassTxt.Text)
           || string.IsNullOrEmpty(majorBox.Text) || string.IsNullOrEmpty(specialtyBox.Text))
        {
            MessageBox.Show("You must enter in all fields before moving forward");
        }
        else
        {
            //would this save my data to the array and how can I reload this?
            Members m1 = new Members(firstNameTxt.Text, lastNameTxt.Text, userNameTxt.Text,
                                        passwordTxt.Text, confPassTxt.Text, majorBox.Text,
                                        specialtyBox.Text);
            lstMembers.Add(m1);
        }
    }
   private void loadLastBtn_Click(object sender, EventArgs e)
    {
          for(int i = 0; i < lstMembers.Count; i++)
        {
            firstNameTxt.Text = lstMembers[i].FirstName;
            lastNameTxt.Text = lstMembers[i].LastName;
            userNameTxt.Text = lstMembers[i].UserName;
            passwordTxt.Text = lstMembers[i].Password;
            confPassTxt.Text = lstMembers[i].ConfPassword;
            majorBox.Text = lstMembers[i].Major;
            specialtyBox.Text = lstMembers[i].Specialty;
        }
    }

Here is the user object I created. I am just unsure how to call it now when I want to save and reload.

    class Members
{
    private string firstName;
    private string lastName;
    private string userName;
    private string password;
    private string confPassword;
    private string major;
    private string specialty;

    public Members(string firstName, string lastName, string userName, string password,
                    string confPassword, string major, string specialty)
    {
        this.firstName = firstName;
        this.lastName = lastName;
        this.userName = userName;
        this.password = password;
        this.confPassword = confPassword;
        this.major = major;
        this.specialty = specialty;
    }
    public string FirstName
    {
        get
        {
            return firstName;
        }
        set
        {
            FirstName = firstName;
        }
    }
    public string LastName
    {
        get
        {
            return lastName; 
        }
        set
        {
            LastName = lastName;
        }
    }
    public string UserName
    {
        get
        {
            return userName;
        }
        set
        {
            UserName = userName;
        }
    }
    public string Password
    {
        get
        {
            return password;
        }
        set
        {
            Password = password;
        }
    }
    public string ConfPassword
    {
        get
        {
            return confPassword;
        }
        set
        {
            ConfPassword = confPassword;
        }
    }
    public string Major
    {
        get
        {
            return major;
        }
        set
        {
            Major = major;
        }
    }
    public string Specialty
    {
        get
        {
            return specialty;
        }
        set
        {
            Specialty = specialty;
        }
    }

Answer 1

Well, most common way to do it without any hard implementation would be writing all of your variables with ';' between them within a file. Then read it from file and re-assign it into your form elements when user press down a button.Check this guide to how to write into file:

https://msdn.microsoft.com/en-us/library/8bh11f1k.aspx

I'll give an simple example:

For example my form consist of username and password TextFields. After user entered them and pressed login, I save them into file for next time user logs in, this method will save it.

public void save(){
String username = txtUsername.Text;
String password = txtPassword.Text;
File.WriteAllText(path, username + ";" + password);
}

public void load(){
String parameters = File.ReadAllText(path);
String[] splitted = parameters.split(';');
txtUsername.Text = splitted[0];
txtPassword.Text = splitted[1];
}

Answer 2

I would suggest creating a 'POCO' (Plain old c# object) or struct that will hold your data. When you want to save it, just serialize it to disk (either using MS Serialization (more here, or by using JSON serialize method (more here).
This way, you don't worry about what the user might have entered (less worries about sanitizing the data and making sure he didn't use your escape character).