C#

=/// <summary>Releases all resources used by the <see cref="T:System.ComponentModel.Component" />.</summary>
public void Dispose()
{
  this.Dispose(true);
  GC.SuppressFinalize((object) this);
}

Key point: Controls added to a ControlCollection and docked 'Top followed by the use of 'BringToFront on the Control will be added beneath other controls. When one of these controls is removed/deleted, the other Controls will rearrange so that the order is maintained.

Quote:

a.1. set event handlers for the ToDo close-button Click, and checkbox CheckStateChanged, events.

public ToDo()
{
    InitializeComponent();
    CbxDone = cbxDone;
    LblID = lblId;
    BtnClose = btnClose;
    TxtBx = textBox1;
}

public CheckBox CbxDone { set; get; }
public Label LblID { set; get; }
public Button BtnClose { set; get; }
public TextBox TxtBx { set; get; }

private void btnAdd_Click(object sender, EventArgs e)
{
    ToDo todo = new ToDo();
    currentToDos.Add(todo);  // a list of all hosted controls
    currentToDo = todo;      // current hosted vontrol

    todo.LblID.Text = (idCount).ToString();
    idCount++;

    // attach the EventHandlers
    todo.Enter += TodoOnEnter;
    todo.Leave += TodoOnLeave;

    todo.BtnClose.Click += BtnCloseOnClick;

    todo.CbxDone.CheckStateChanged += CbxDoneOnCheckStateChanged;
    
    todopanel.Controls.Add(todo);
    todo.Dock = DockStyle.Top;
    todo.BringToFront();

    this.ActiveControl = todo;
}

currentToDos.Remove(currentToDo);
this.todopanel.Controls.Remove(currentToDo);
currentToDo.Dispose();

this.Invalidate();

using System.Windows.Forms;

namespace ToDo
{
    public partial class Item : UserControl
    {
        public Panel ItemPanel { set; get; }
        public CheckBox DoneCheckBox { set; get; }
        public Button DeleteButton { set; get; }
        public TextBox UserTextBox { set; get; }

        public Item()
        {
            InitializeComponent();

            ItemPanel = itemPanel;
            DoneCheckBox = doneCheckBox;
            DeleteButton = deleteButton;
            UserTextBox = userTextBox;
        }
    }
}

List<Item> itemList = new List<Item>();
Item crtItem;

void AddItem()
{
    if (inputTextBox.Text != "")
    {
        Item item = new Item();
        itemList.Add(item);
        crtItem = item;
        item.Dock = DockStyle.Top;
        item.UserTextBox.Text = inputTextBox.Text;
        item.Enter += Item_Enter;
        item.Leave += Item_Leave;
        item.DoneCheckBox.CheckedChanged += DoneCheckBox_CheckedChanged;
        item.DeleteButton.Click += DeleteButton_Click;
        itemPanel.Controls.Add(item);
        item.BringToFront();

        inputTextBox.Text = "";
        itemsLabel.Text = itemList.Count + " item(s)";
    }

    inputTextBox.Focus();
}

private void Item_Enter(object sender, EventArgs e)
{
    crtItem.ItemPanel.BackColor = Color.FromArgb(200, 233, 253);
    crtItem.UserTextBox.BackColor = Color.FromArgb(200, 233, 253);
}

private void Item_Leave(object sender, EventArgs e)
{
    crtItem.ItemPanel.BackColor = Color.FromArgb(240, 240, 240);
    crtItem.UserTextBox.BackColor = Color.FromArgb(240, 240, 240);
}

private void DoneCheckBox_CheckedChanged(object sender, EventArgs e)
{
    if (crtItem.DoneCheckBox.Checked)
    {
        crtItem.UserTextBox.ForeColor = Color.FromArgb(150, 150, 150);
        crtItem.UserTextBox.Font = new Font("Segoe UI", 18F, FontStyle.Strikeout, GraphicsUnit.Point, 0);
    }
    else
    {
        crtItem.UserTextBox.ForeColor = Color.FromArgb(0, 0, 0);
        crtItem.UserTextBox.Font = new Font("Segoe UI", 18F, FontStyle.Regular, GraphicsUnit.Point, 0);
    }
}

private void DeleteButton_Click(object sender, EventArgs e)
{
    itemList.Remove(crtItem);
    itemPanel.Controls.Remove(crtItem);
    crtItem.Dispose();

    Invalidate();
}

alin1 wrote:

How do I update its value when I click a random Item usercontrol?

private void Item_Enter(object sender, EventArgs e)
{
    crtItem = (Item)sender;
    crtItem.ItemPanel.BackColor = Color.FromArgb(200, 233, 253);
    crtItem.UserTextBox.BackColor = Color.FromArgb(200, 233, 253);
}

private void Item_Leave(object sender, EventArgs e)
{
    crtItem = (Item)sender;
    crtItem.ItemPanel.BackColor = Color.FromArgb(240, 240, 240);
    crtItem.UserTextBox.BackColor = Color.FromArgb(240, 240, 240);
}

Quote:

Are there any circumstances where you would want to keep track of not only the current active 'Item, but, the previous one ?

SELECT * 
FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE ccu
WHERE ccu.CONSTRAINT_NAME = 'UserIDfk'

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;

namespace DAQ_Simulator
{
    public partial class Form1 : Form
    {
        int counter;
        private DateTime datetime;
        private DateTime datetime2;
        //double next_samplingtime += DateTime.Now;
        //int maxSid = 10; //Number of sensors 7analog and 3 digital
        int maxAI = 7; 
        int maxDI=3;
        int maxSid =11;
        
        // Create an array of 10 sensor objects
        Sensor[] sObj = new Sensor[11];

        public Form1()
        {
            InitializeComponent();

            for (counter = 0; counter < maxSid; counter++)
            {
                sObj[counter] = new Sensor(counter);
            }
        }
        private void displaySensorData(object sender, EventArgs e)
        {
        }
        private void groupSampl_Enter(object sender, EventArgs e)
        {

        }
        private void textSampling_TextChanged(object sender, EventArgs e)
        {
        }
        private void btnSampling_Click(object sender, EventArgs e)
        {
            timer1.Interval = 5900; // sampling time specified in miliseconds
            timer1.Start();
            btnSampling.Enabled = false;
            sampling(); // sample the signals

            datetime2 = DateTime.Now.AddSeconds(5).AddMilliseconds(900);
            string time2 = datetime2.Hour + ":" + datetime2.Minute + ":" + datetime2.Second + "." + datetime2.Millisecond;
            textSampling.Text =time2;
            //  System.TimeSpan diff1 = datetime2.Subtract(datetime);        
        }

    private void groupLogg_Enter(object sender, EventArgs e)
    {
    }
    private void txtLogging_TextChanged(object sender, EventArgs e)
    {
    }
    private void labelLoggingText_Click(object sender, EventArgs e)
    {
    }
    private void btnLogging_Click(object sender, EventArgs e)
    {
    }
    private void labelSensorValues_Click(object sender, EventArgs e)
    {
    }
    private void textSensorValues_TextChanged(object sender, EventArgs e)
    {
    }
    private void timer1_Tick(object sender, EventArgs e)
    {
         btnSampling.Enabled = true;
         timer1.Stop();
    }
    private void sampling()
    {
          
            datetime = DateTime.Now;
           
            string time = datetime.Hour + ":" + datetime.Minute + ":" + datetime.Second + "." + datetime.Millisecond;
            
            // Get the object values as a string

            double sensVal1 = sObj[1].GetAnalogValue();
            double sensVal2 = sObj[2].GetAnalogValue();
            double sensVal3 = sObj[3].GetAnalogValue();
            double sensVal4 = sObj[4].GetAnalogValue();
            double sensVal5 = sObj[5].GetAnalogValue();
            double sensVal6 = sObj[6].GetAnalogValue();
            double sensVal7 = sObj[7].GetAnalogValue();
            
            int sensVal8 = sObj[8].GetDigitalValue();
            int sensVal9 = sObj[9].GetDigitalValue();
            int sensVal10 = sObj[10].GetDigitalValue();

            //Analog values converted to strings and stored in variables 
            String analogSens1 = sensVal1.ToString("F3");
            String analogSens2 = sensVal2.ToString("F3");
            String analogSens3= sensVal3.ToString("F3");
            String analogSens4 = sensVal4.ToString("F3");
            String analogSens5 = sensVal5.ToString("F3");
            String analogSens6 = sensVal6.ToString("F3");
            String analogSens7 = sensVal7.ToString("F3");

            //Digital values converted to strings and stored in variables
            String digSens8 = sensVal8.ToString("F0");
            String digSens9 = sensVal9.ToString("F0");
            String digSens10 = sensVal10.ToString("F0");

            textSensorValues.Text += ("  " + time + "  " + analogSens1 + "  " + analogSens2+ "  " + analogSens3 + "  " + analogSens4+
                "  "+ analogSens5+"  "+analogSens6+"  "+ analogSens7+"  "+digSens8+"  "+digSens9+"  "+digSens10+"\r\n");

            /*
                        for (int id = 0; id < maxAI; id++)
                       {
                            double y = sObj[id].GetAnalogValue();
                            if (id==0)
                            {
                                textSensorValues.Text += time+ " ," + sTxt + "V,";

                            }
                        }

                        for (counter = 0; counter < maxDI; counter++)
                        {

                           // sTxt1 += sObj[3].GetDigitalValue().ToString();
                        }

                */
           
            }
        
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DAQ_Simulator
{
    public class Sensor
    {
        Random ranDigVal;
        double AnalogVal;
        int DigVal;
        int sId;
        Random rSensVal;

        public Sensor(int id)
        {
            sId = id;
            rSensVal = new Random(id);
            ranDigVal = new Random(id);
            AnalogVal = 0.0F;
        }
        
        public double GetAnalogValue(double minAnalogVolt=0.00F,double maxAnalogVolt=1.00F)
        {
            if(minAnalogVolt <= AnalogVal && AnalogVal<= maxAnalogVolt)

                 AnalogVal = rSensVal.NextDouble();
                 return AnalogVal;         
       }
        public int GetDigitalValue(int digMin = 0, int digMax = 1)
        {

            DigVal = ranDigVal.Next(0, 2);
            return DigVal;
        }
        public int GetSensId()
        {
            return sId;
        }      
    }
}