Контрол мега простой, текст бокс и дропдаун минуты/часы/дни/недели. Возвращает и получает TimeSpan, используется для two-way binding. Он работает, но я подозреваю, что какие-нить гайдлайны и прочие заветы Эспозито я нарушил. Так ли это? Особенно смущает меня RegisterRequiresPostBack

using System;
using System.Collections.Specialized;
using System.Web.UI;

public partial class TimeSpanControl : UserControl, IValidator, IPostBackDataHandler
{
    public enum Period
    {
        Minutes, Hours, Days, Weeks
    }

    public TimeSpan? Duration
    {
        get { return ViewState["Duration"] as TimeSpan?; }
        set { ViewState["Duration"] = value; }
    }

    public Period? PeriodType
    {
        get { return ViewState["PeriodType"] as Period?; }
        set { ViewState["PeriodType"] = value; }
    }

    public int? TotalHours
    {
        get { return Duration == null ? null : (int?) Duration.Value.TotalHours; }
        set 
        { 
            if(value == null)
            {
                Duration = null;
            } 
            else
            {
                Duration = new TimeSpan(value.Value, 0,0);
            }
        }
    }

    public int? TotalMinutes
    {
        get { return Duration == null ? null : (int?)Duration.Value.TotalMinutes; }
        set
        {
            if (value == null)
            {
                Duration = null;
            }
            else
            {
                Duration = new TimeSpan(0, value.Value, 0);
            }
        }
    }

    public int? TotalDays
    {
        get { return Duration == null ? null : (int?)Duration.Value.TotalDays; }
        set
        {
            if (value == null)
            {
                Duration = null;
            }
            else
            {
                Duration = new TimeSpan(value.Value, 0, 0, 0);
            }
        }
    }
    
    private void InitControls() {
        Period period = PeriodType ?? GetBestPeriod();
        switch (period)
        {
            case Period.Minutes:
                DurationText.Text = Duration == null ? "" : Duration.Value.TotalMinutes.ToString();
                PeriodTypeList.SelectedValue = Period.Minutes.ToString();
                break;
            case Period.Hours:
                DurationText.Text = Duration == null ? "" : Duration.Value.TotalHours.ToString();
                PeriodTypeList.SelectedValue = Period.Hours.ToString();
                break;
            case Period.Days:
                DurationText.Text = Duration == null ? "" : Duration.Value.TotalDays.ToString();
                PeriodTypeList.SelectedValue = Period.Days.ToString();
                break;
            case Period.Weeks:
                DurationText.Text = Duration == null ? "" : (Duration.Value.TotalDays / 7).ToString();
                PeriodTypeList.SelectedValue = Period.Weeks.ToString();
                break;
        }
    }

    private void ParseDuration() 
    {
        Period period;
        Enum.TryParse(PeriodTypeList.SelectedValue, out period);
        PeriodType = period;
        int duration = Int32.Parse(DurationText.Text);
        switch (period)
        {
            case Period.Minutes:
                Duration = new TimeSpan(0,duration, 0);
                break;
            case Period.Hours:
                Duration = new TimeSpan(duration, 0, 0);
                break;
            case Period.Days:
                Duration = new TimeSpan(duration, 0, 0, 0);
                break;
            case Period.Weeks:
                Duration = new TimeSpan(duration * 7 , 0, 0, 0);
                break;
        }
    }

    protected override void OnPreRender(EventArgs e)
    {
        Page.RegisterRequiresPostBack(this);
        base.OnPreRender(e);
        if(!IsPostBack)
        {
            InitControls();
        }
    }

    private Period GetBestPeriod()
    {
        if(Duration == null)
        {
            return Period.Hours;
        }
        
        int minutes = (int) Duration.Value.TotalMinutes;
        if(minutes % 60 != 0)
        {
            return Period.Minutes;
        }
        if(minutes % (60 * 24) != 0)
        {
            return Period.Hours;
        }
        return minutes % (60 * 24 * 7) != 0 ? Period.Days : Period.Weeks;
    }

    public void Validate()
    {
        DurationValidator.Validate();
    }

    public bool IsValid
    {
        get { return DurationValidator.IsValid; }
        set { DurationValidator.IsValid = value; }
    }

    public string ErrorMessage
    {
        get { return DurationValidator.ErrorMessage; }
        set { DurationValidator.ErrorMessage = value; }
    }

    public bool LoadPostData(string postDataKey, NameValueCollection postCollection)
    {
        ParseDuration();
        return true;
    }

    public void RaisePostDataChangedEvent()
    {
    }
}