I came across a question on StackOverflow that asked how you can copy Properties from one class to the other assuming they had similar properties.
public class Student
{
public int Id {get; set;}
public string Name {get; set;}
public IList<Course> Courses{ get; set;}
}
public class StudentDTO
{
public int Id {get; set;}
public string Name {get; set;}
public IList<CourseDTO> Courses{ get; set;}
}
I would like to copy value from Student class to StudentDTO class:
var student = new Student();
StudentDTO studentDTO = student;
How can I do that by reflection or other solution?
The code someone posted on there linked to Miscellaneous Utility Library and that Property Copy was awesomely constructed. Have a gander at the result below and tell me it doesn’t blow your mind!!
using System;
using System.Collections;
using System.Collections.Specialized;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.ComponentModel;
using System.Linq.Expressions;
namespace ConsoleApplication1
{
class Program
{
public class Student
{
public int Id { get; set; }
public string Name { get; set; }
public IList<int> Courses { get; set; }
public static implicit operator Student(StudentDTO studentDTO)
{
return PropertyCopy<Student>.CopyFrom(studentDTO);
}
}
public class StudentDTO
{
public int Id { get; set; }
public string Name { get; set; }
public IList<int> Courses { get; set; }
public static implicit operator StudentDTO(Student student)
{
return PropertyCopy<StudentDTO>.CopyFrom(student);
}
}
static void Main(string[] args)
{
Student _student = new Student();
_student.Id = 1;
_student.Name = "Timmmmmmmmaaaahhhh";
_student.Courses = new List<int>();
_student.Courses.Add(101);
_student.Courses.Add(121);
StudentDTO itemT = _student;
Console.WriteLine(itemT.Id);
Console.WriteLine(itemT.Name);
Console.WriteLine(itemT.Courses.Count);
}
}
// COOLEST PIECE OF CODE FROM - http://www.yoda.arachsys.com/csharp/miscutil/
/// <summary>
/// Generic class which copies to its target type from a source
/// type specified in the Copy method. The types are specified
/// separately to take advantage of type inference on generic
/// method arguments.
/// </summary>
public class PropertyCopy<TTarget> where TTarget : class, new()
{
/// <summary>
/// Copies all readable properties from the source to a new instance
/// of TTarget.
/// </summary>
public static TTarget CopyFrom<TSource>(TSource source) where TSource : class
{
return PropertyCopier<TSource>.Copy(source);
}
/// <summary>
/// Static class to efficiently store the compiled delegate which can
/// do the copying. We need a bit of work to ensure that exceptions are
/// appropriately propagated, as the exception is generated at type initialization
/// time, but we wish it to be thrown as an ArgumentException.
/// </summary>
private static class PropertyCopier<TSource> where TSource : class
{
private static readonly Func<TSource, TTarget> copier;
private static readonly Exception initializationException;
internal static TTarget Copy(TSource source)
{
if (initializationException != null)
{
throw initializationException;
}
if (source == null)
{
throw new ArgumentNullException("source");
}
return copier(source);
}
static PropertyCopier()
{
try
{
copier = BuildCopier();
initializationException = null;
}
catch (Exception e)
{
copier = null;
initializationException = e;
}
}
private static Func<TSource, TTarget> BuildCopier()
{
ParameterExpression sourceParameter = Expression.Parameter(typeof(TSource), "source");
var bindings = new List<MemberBinding>();
foreach (PropertyInfo sourceProperty in typeof(TSource).GetProperties())
{
if (!sourceProperty.CanRead)
{
continue;
}
PropertyInfo targetProperty = typeof(TTarget).GetProperty(sourceProperty.Name);
if (targetProperty == null)
{
throw new ArgumentException("Property " + sourceProperty.Name + " is not present and accessible in " + typeof(TTarget).FullName);
}
if (!targetProperty.CanWrite)
{
throw new ArgumentException("Property " + sourceProperty.Name + " is not writable in " + typeof(TTarget).FullName);
}
if (!targetProperty.PropertyType.IsAssignableFrom(sourceProperty.PropertyType))
{
throw new ArgumentException("Property " + sourceProperty.Name + " has an incompatible type in " + typeof(TTarget).FullName);
}
bindings.Add(Expression.Bind(targetProperty, Expression.Property(sourceParameter, sourceProperty)));
}
Expression initializer = Expression.MemberInit(Expression.New(typeof(TTarget)), bindings);
return Expression.Lambda<Func<TSource,TTarget>>(initializer, sourceParameter).Compile();
}
}
}
}
Aboutdev's Weblog 