C#

public class UIForm
{
    public class TimeSet
    {
        private TextBox _txtAllottedTime;
        private TextBox _txtStartTime;
        private TextBox _txtEndTime;
        private Label _lblOverTime;
        private Label _lblOverTimePercentage;
        private int _overTime;
        private int _completeTime;

        public TimeSpan AllottedTime =>
            TimeSpan.Parse(_txtAllottedTime.Text);
        private DateTime StartTime =>
            DateTime.Parse(_txtStartTime.Text);
        private DateTime EndTime =>
            DateTime.Parse(_txtEndTime.Text);

        public TimeSet(
            TextBox txtAllottedTime,
            TextBox txtStartTime,
            TextBox txtEndTime,
            Label lblOverTime,
            Label lblOverTimePercentage,
            int overTime,
            int completeTime)
        {
            _txtAllottedTime = txtAllottedTime;
            _txtStartTime = txtStartTime;
            _txtEndTime = txtEndTime;
            _lblOverTime = lblOverTime;
            _lblOverTimePercentage = lblOverTimePercentage;
            OverTime = overTime;
            _completeTime = completeTime;
        }

        public int OverTime
        {
            get => _overTime;
            private set
            {
                _overTime = value;
                _lblOverTime.Text = value.ToString();
            }
        }

        public bool TextWasEnteredByUser =>
            string.IsNullOrEmpty(AllottedTime.Text) ||
            string.IsNullOrEmpty(StartTime.Text) ||
            string.IsNullOrEmpty(EndTime.Text);

        public TimeSpan Duration
        {
            get
            {
                DateTime end = EndTime;

                if (StartTime > end)
                {
                    end = end.AddDays(1);
                }

                return end.Subtract(StartTime);
            }
        }

        private int Percentage
        {
            get
            {
                _completeTime++;
                int percentage = (OverTime * 100) / _completeTime;
                _lblOverTimePercentage.Text = percentage.ToString();
                return percentage;
            }
        }

        public bool ShouldWarnWarden() =>
            (Percentage > 50);

        public void CheckForOverTime()
        {
            //If the start time is greater than end that means the diff is above 12 hours
            //So subtracting the hours from a day to get the number of hours used if (TimeSpan.Compare(alloted, duration) == -1)
            if (TimeSpan.Compare(AllottedTime, Duration) == -1)
            {
                OverTime++;
            }
        }
    }

    private readonly List<TimeSet> TimeSets = new List<TimeSet>
    {
        // initialize parameters here.  I don't know what you want for these integers.
        new TimeSet(txtTimeLimit1, txtEntryTime1, txtExitTime1, lblOverTime1, _lblOverTimePercentage1, 0, 0),
        new TimeSet(txtTimeLimit2, txtEntryTime2, txtExitTime2, lblOverTime2, _lblOverTimePercentage2, 0, 0),
        new TimeSet(txtTimeLimit3, txtEntryTime3, txtExitTime3, lblOverTime3, _lblOverTimePercentage3, 0, 0)
    };

    public void park1() =>
        park(TimeSets[0]);

    public void park2() =>
        park(TimeSets[1]);

    public void park3() =>
        park(TimeSets[2]);

    private void park(TimeSet timeSet)
    {
        if (!timeSet.TextWasEnteredByUser)
        {
            MessageBox.Show("Enter all time values");
        }
        else
        {
            timeSet.CheckForOverTime();

            if (timeSet.ShouldWarnWarden())
            {
                warnWarden();
            }
        }
    }
}

List<int> SelectedImagesIndexes = new List<int>();

private void LstViewOnItemSelectionChanged(object sender, ListViewItemSelectionChangedEventArgs e)
{
    int ndx = e.Item.ImageIndex;

    // no image ?
    if(ndx == -1) return;

    bool inlist = SelectedImagesIndexes.Contains(ndx);

    if (e.Item.Selected)
    {
        if (! inlist)
        {
            SelectedImagesIndexes.Add(ndx);
        }
    }
    else
    {
        if (inlist)
        {
            SelectedImagesIndexes.Remove(ndx);
        }
    }
}

PKSubudhi wrote:

without using any API or SMS Gateway

OriginalGriff wrote:

The C# code of a webapp ruins on the server