How do I save information from an GUI into a XML-file on the computer?

See more:

C#

XML

Visual-Studio

I've created a program where users can input a few information and then can save everything into an xml file, or open it.

Before I setup that save and open thing on the bigger scale, I created a small test-run to find a solution. There are three textboxes where you can input your own information, two checkboxes and comboboxes where users can choose from a few options. I've created a open and save menu-strip-button but can't think of a way how to save all those information into a xml.file.

What I have tried:

This is what I've so far:

using System;
using System.IO;
using System.Windows.Forms;

namespace TestApp
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void openToolStripMenuItem_Click(object sender, EventArgs e)
        {

        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void openToolStripMenuItem_Click_1(object sender, EventArgs e)
        {
            var fileContent = string.Empty;
            var filePath = string.Empty;

            using (OpenFileDialog openFileDialog = new OpenFileDialog())
            {
                openFileDialog.InitialDirectory = "c:\\";
                openFileDialog.Filter = "XML-File | *.xml|All files (*.*)|*.*";
                openFileDialog.FilterIndex = 2;
                openFileDialog.RestoreDirectory = true;

                if (openFileDialog.ShowDialog() == DialogResult.OK)
                {
                    //Get the path of specified file
                    filePath = openFileDialog.FileName;

                    //Read the contents of the file into a stream
                    var fileStream = openFileDialog.OpenFile();

                    using (StreamReader reader = new StreamReader(fileStream))
                    {
                        fileContent = reader.ReadToEnd();
                    }
                }
            }

            //MessageBox.Show(fileContent, "File Content at path: " + filePath, MessageBoxButtons.OK);
        }

        private void saveToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Stream myStream;
            SaveFileDialog saveFileDialog1 = new SaveFileDialog();

            saveFileDialog1.Filter = "XML-File | *.xml|All files (*.*)|*.*";
            saveFileDialog1.FilterIndex = 2;
            saveFileDialog1.RestoreDirectory = true;

            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                if ((myStream = saveFileDialog1.OpenFile()) != null)
                {
                    // Code to write the stream goes here.
                    myStream.Close();
                }
            }
        }

        /*private void validateUserEntry()
        {
            // Checks the value of the text.
            if (textBox1.Text.Length == 0 && textBox2.Text.Length == 0 && textBox3.Text.Length == 0)
            {
                // Initializes the variables to pass to the MessageBox.Show method.
                string message = " AAAAAAAAAAAAA";
                string caption = "Error Detected in Input";
                MessageBoxButtons buttons = MessageBoxButtons.YesNo;
                DialogResult result;

                // Displays the MessageBox.
                result = MessageBox.Show(message, caption, buttons);
                if (result == System.Windows.Forms.DialogResult.Yes)
                {
                    // Closes the parent form.
                    this.Close();
                }
            }
        }*/

    }
}