I think most developers start this way (code behind instead of XAML). XAML isn't immediately intuitive, but once you cross the boundary (of understanding) XAML tends to be a simpler approach. And, frankly, I tend to think that simplicity is always the better choice
<div class="container">
<h4 class="alert alert-info">
فرمهای بوت استرپ 3</h4>
<div class="row">
<article class="registrationform">
<h2>
فرم ثبت نام</h2>
<form class="registration form-horizontal" action="#">
<fieldset id="personalinfo">
<legend>اطلاعات شخصی</legend>
<section class="row">
<label class="col col-lg-4 control-label" for="myname">
نام</label>
<div class="controls">
<input class="col col-lg-8" type="text" name="myname"
id="myname" autofocus placeholder="نام و نام خانوادگی"
required>
</div>
<!-- controls -->
</section><!-- row -->
<section class="row">
<label class="col col-lg-4 control-label" for="companyname">
نام شرکت</label>
<div class="controls">
<input class="col col-lg-8" type="text" name="companybname" id="companyname" />
</div>
<!-- controls -->
</section><!-- row -->
<section class="row">
<label class="col col-lg-4 control-label" for="myemail">
ایمیل</label>
<div class="controls">
<input class="col col-lg-8" type="email" name="myemail" id="myemail"
required autocomplete="off" />
</div>
<!-- controls -->
</section><!-- row -->
</fieldset>
<!-- personal info -->
<fieldset id="otherinfo">
<legend>سایر اطلاعات</legend>
<section class="row">
<label class="col col-lg-4 control-label">
نوع درخواست</label>
<div class="controls col col-lg-8">
<label class="radio">
<input type="radio" name="requesttype" value="question" />
سؤال
</label>
<label class="radio">
<input type="radio" name="requesttype" value="comment" />
انتقاد
</label>
</div>
<!-- controls -->
</section><!-- row -->
<section class="row">
<label class="col col-lg-4 control-label">
خبرنامه</label>
<div class="controls col col-lg-8">
<label class="checkbox">
<input type="checkbox" id="subscribe" name="subscribe" checked value="yes" />
آیا مایل به دریافت ایمیلهای خبرنامه ما هستید؟
</label>
</div>
<!-- controls -->
</section><!-- row -->
<section class="row">
<label class="col col-lg-4 control-label" for="reference">
چطور از وجود سایت ما آگاه شدید؟</label>
<div class="controls col col-lg-8">
<select name="reference" id="reference">
<option>لطفا انتخاب کنید...</option>
<option value="friend">از طریق یک دوست</option>
<option value="facebook">Facebook</option>
<option value="twitter">Twitter</option>
</select>
</div>
<!-- controls -->
</section><!-- row -->
</fieldset>
<button class="btn" type="submit">
ارسال</button>
</form>
</article>
</div>
<!-- end row -->
</div>
<!-- /container --> 
public object ProcessingBoundary(IList<SummaryCellData> columnCellsSummaryData)
{
if (columnCellsSummaryData == null || !columnCellsSummaryData.Any()) return 0;
var list = columnCellsSummaryData;
var lastItem = list.Last();
return lastItem.CellData.PropertyValue;
} Method 'set_DisplayFormatFormula' in type 'Hezareh.Modules.Accounting.Reporting.ViewModels.MySampleAggregateFunction' from assembly 'Hezareh.Modules.Accounting, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' does not have an implementation.
public class MySampleAggregateFunction : IAggregateFunction
{
public MySampleAggregateFunction()
{
}
/// <summary>
/// Fires before rendering of this cell.
/// Now you have time to manipulate the received object and apply your custom formatting function.
/// It can be null.
/// </summary>
public Func<object, string> DisplayFormatFormula { set; get; }
#region Fields (6)
double _groupAvg;
long _groupRowNumber;
double _groupSum;
double _overallAvg;
long _overallRowNumber;
double _overallSum;
#endregion Fields
#region Properties (2)
/// <summary>
/// Returns current groups' aggregate value.
/// </summary>
public object GroupValue
{
get { return _groupAvg; }
}
/// <summary>
/// Returns current row's aggregate value without considering the presence of the groups.
/// </summary>
public object OverallValue
{
get { return _overallAvg; }
}
#endregion Properties
#region Methods (4)
// Public Methods (1)
/// <summary>
/// Fires after adding a cell to the main table.
/// </summary>
/// <param name="cellDataValue">Current cell's data</param>
/// <param name="isNewGroupStarted">Indicated starting a new group</param>
public void CellAdded(object cellDataValue, bool isNewGroupStarted)
{
checkNewGroupStarted(isNewGroupStarted);
_overallRowNumber++;
_groupRowNumber++;
double cellValue;
if (double.TryParse(cellDataValue.ToSafeString(), NumberStyles.AllowThousands | NumberStyles.AllowLeadingSign, CultureInfo.InvariantCulture, out cellValue))
{
groupAvg(cellValue);
overallAvg(cellValue);
}
}
// Private Methods (3)
private void checkNewGroupStarted(bool newGroupStarted)
{
if (newGroupStarted)
{
_groupRowNumber = 0;
_groupAvg = 0;
_groupSum = 0;
}
}
private void groupAvg(double cellValue)
{
_groupSum += cellValue;
_groupAvg = _groupSum / _groupRowNumber;
}
private void overallAvg(double cellValue)
{
_overallSum += cellValue;
_overallAvg = _overallSum / _overallRowNumber;
}
/// <summary>
/// A general method which takes a list of data and calculates its corresponding aggregate value.
/// It will be used to calculate the aggregate value of each pages individually, with considering the previous pages data.
/// </summary>
/// <param name="columnCellsSummaryData">List of data</param>
/// <returns>Aggregate value</returns>
public object ProcessingBoundary(IList<SummaryCellData> columnCellsSummaryData)
{
if (columnCellsSummaryData == null || !columnCellsSummaryData.Any()) return 0;
var list = columnCellsSummaryData;
var lastItem = list.Last();
return lastItem.CellData.PropertyValue;
}
#endregion Methods
} columns.AddColumn(column =>
{
column.PropertyName<VoucherRowPrintViewModel>(x => x.CaclulatedRemains);
column.CellsHorizontalAlignment(PdfRpt.Core.Contracts.HorizontalAlignment.Right);
column.IsVisible(true);
column.Order(5);
column.Width(1.5f);
column.ColumnItemsTemplate(template =>
{
template.TextBlock();
template.DisplayFormatFormula(obj => obj == null ? string.Empty : string.Format("{0:n0}", obj));
});
column.AggregateFunction(aggregateFunction =>
{
aggregateFunction.CustomAggregateFunction(new MySampleAggregateFunction());
aggregateFunction.DisplayFormatFormula(obj => obj == null ? string.Empty : string.Format("{0:n0}", obj));
});
column.HeaderCell("مانده");
}); 
<%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master"
Inherits="System.Web.Mvc.ViewPage<System.Web.Mvc.HandleErrorInfo>" %>
<asp:Content ID="errorTitle" ContentPlaceHolderID="TitleContent" runat="server">
Error
</asp:Content>
<asp:Content ID="errorContent" ContentPlaceHolderID="MainContent" runat="server">
<h2>
Sorry, an error occurred while processing your request.
</h2>
</asp:Content>
using System.Linq.Expressions;
public class ContextWithExtensionExample
{
public void DoSomeContextWork(DbContext context)
{
var uni = new Unicorn();
context.Set<Unicorn>().AddIfNotExists(uni , x => x.Name == "James");
}
}
public static class DbSetExtensions
{
public static T AddIfNotExists<T>(this DbSet<T> dbSet, T entity, Expression<Func<T, bool>> predicate = null) where T : class, new()
{
var exists = predicate != null ? dbSet.Any(predicate) : dbSet.Any();
return !exists ? dbSet.Add(entity) : null;
}
} 