[C#] - MultiClip (Main)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;

namespace clipKeep
{
    public partial class mainForm : Form
    {
        public mainForm()
        {
            InitializeComponent();
        }

        //Holds all of the strings, allows for a search function with one listbox
        List<string> allItems = new List<string>();

        //Where the save file is stored
        string listLocation = Directory.GetCurrentDirectory() + "/savedList.ini";

        //How the strings are split. Not reading line by line because some C&P's may have multiple lines
        string splitVar = "[][][][][]";

        //Base variable for the saving
        string doBuild = "";

        private void mainForm_Load(object sender, EventArgs e)
        {
            //If the file doesn't exist; then create one
            if (!File.Exists(listLocation))
            {
                var tempOpen = File.Create(listLocation);
                tempOpen.Close();

                MessageBox.Show("Couldn't find a saved list; created new one!", "MultiClip");

                allItems.Add("Created by vRice");
                allItems.Add("http://www.youtube.com/vintagerice");

                updateProgram();
            }
            else
            {
                //Splits with a string rather than a char
                string[] splitText = File.ReadAllText(listLocation).Split(new string[] { splitVar }, StringSplitOptions.None);

                //Adds all items to the listbox
                foreach (string newItem in splitText)
                {
                    if(newItem != "")
                    {
                        allItems.Add(newItem);
                        updateProgram();
                    }
                }
            }
        }

        //'Brain' of the program, monitors all clipboard content
        private void checkTimer_Tick(object sender, EventArgs e)
        {
            string newText = Clipboard.GetText();

            if (!itemList.Items.Contains(newText))
            {
                if (newText != "")
                {
                    allItems.Add(newText);
                    updateProgram();
                }
            }
        }

        public void updateProgram()
        {
            itemList.Items.Clear();
            Clipboard.Clear();

            doBuild = "";

            foreach (string newItem in allItems)
            {
                //Adds each string to the variable with a split between them
                itemList.Items.Add(newItem);
                doBuild += (newItem + splitVar);
            }

            // Writes the string to the save file
            if (File.Exists(listLocation))
                File.WriteAllText(listLocation, doBuild);
        }

        private void delButton_Click(object sender, EventArgs e)
        {
            if (itemList.SelectedIndex >= 0)
            {
                allItems.RemoveAt(itemList.SelectedIndex);
                updateProgram();
            }
        }

        private void clearButton_Click(object sender, EventArgs e)
        {
            DialogResult userConfirm = MessageBox.Show("Are you sure you want to delete all items?", "multiClip", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2);

            //If user selects yes then delete everything
            if(userConfirm == DialogResult.Yes)
            {
                allItems.Clear();
                updateProgram();
            }
        }

        private void searchBox_TextChanged(object sender, EventArgs e)
        {
            if(searchBox.Text!= "Search")
            {
                itemList.Items.Clear();

                //If the search box contains anything that's in the item list; show the items
                foreach(string toFind in allItems)
                    if (toFind.ToLower().Contains(searchBox.Text.ToLower()))
                        if (!itemList.Items.Contains(toFind))
                            itemList.Items.Add(toFind);
            }
        }

        private void expandButton_Click(object sender, EventArgs e)
        {
            if(itemList.SelectedIndex >= 0)
            {
                //Open a new form that passes on the selected item string
                expandForm openForm = new expandForm(this.itemList.SelectedItem.ToString());
                openForm.ShowDialog();

                //Return the data from the other form if it isn't empty
                if(openForm.textData() != "")
                {
                    allItems.Remove(itemList.SelectedItem.ToString());
                    allItems.Add(openForm.textData());

                    updateProgram();
                }
            }
        }

        private void mainForm_Resize(object sender, EventArgs e)
        {
            //Make the program responsive
            itemList.Height = this.Height - 70;
            itemList.Width = this.Width - 180;
        }

        private void clearBox(object sender, EventArgs e)
        {
            searchBox.Text = "";
        }

        private void itemList_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            Uri uriResult;
            bool urlCheck = Uri.TryCreate(itemList.SelectedItem.ToString(), UriKind.Absolute, out uriResult) && uriResult.Scheme == Uri.UriSchemeHttp;

            //If the item is a link; launch it
            if (urlCheck)
                System.Diagnostics.Process.Start(itemList.SelectedItem.ToString());
        }
    }
}