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Using LINQ and reflection to find matching properties of objects

As a side product of some experiments I wrote simple LINQ query that matches properties of two objects and returns these properties as list. The code I wrote is pretty simple and I packed it for you as method.

C#

public IList<PropertyInfo> GetMatchingProperties(object source, object target)

{

    if (source == null)

        throw new ArgumentNullException("source");

    if (target == null)

        throw new ArgumentNullException("target");

 

    var sourceType = source.GetType();

    var sourceProperties = sourceType.GetProperties();

    var targetType = target.GetType();

    var targetProperties = targetType.GetProperties();

 

    var properties = (from s in sourceProperties

                      from t in targetProperties

                      where s.Name == t.Name &&

                            s.PropertyType == t.PropertyType

                      select s).ToList();

    return properties;

}


VB.NET
Public Function GetMatchingProperties(ByVal source As Object,_
    ByVal target As Object) As IList(Of PropertyInfo)

    If source Is Nothing Then
        Throw New ArgumentNullException("source")
    End If
    If target Is Nothing Then
        Throw New ArgumentNullException("target")
    End If
    
    Dim sourceType = source.GetType()
    Dim sourceProperties = sourceType.GetProperties()
    Dim targetType = target.GetType()
    Dim targetProperties = targetType.GetProperties()
    
    Dim properties = (From s In sourceProperties _
        From t In targetProperties _
        Where s.Name = t.Name AndAlso s.PropertyType = t.PropertyType _
        Select s).ToList()
    Return properties
End Function

The method returns only those properties that match by name and type. If both objects have property called Sum and both of them have Sum in different type (let’s say float and decimal) then this property is not returned by this method. Of course, you can extend this method if you like and you can make it much more clever. Simple implementation given here worked for me very well.

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Posted: Dec 26 2009, 01:25 PM by DigiMortal | with 20 comment(s)
Filed under: , ,

Comments

Lasse Espeholt said:

Cool, but you could also use .Intersects() which is the intended method I think. But yours is properly prettier because the extra "where" syntactic sugar. Best regards, Lasse

# December 26, 2009 1:51 PM

DigiMortal said:

Thanks for feedback, Lasse! I think this where part is pretty important because this somebody may want to add "smarter stuff" there. :)

# December 26, 2009 5:52 PM

Lloyd Sheen said:

Did anyone actually try this.  I just inserted the VB.NET code into a form and it does not compile.

Error 1 Operator '=' is not defined for types 'System.Type' and 'System.Type'. C:\Visual Studio Projects\TestLinqObjectCompare\TestLinqObjectCompare\Form1.vb 30 35 TestLinqObjectCompare

# December 27, 2009 11:28 AM

Marcel Wijnands said:

@Lloyd Sheen: In case of VB.NET, use "Is" instead of "=" on Reference Types.

# January 14, 2010 6:05 PM

Rulett szisztéma said:

Great idea, but will this work over the long run?

# February 19, 2010 8:56 AM

Spielautomaten said:

Wirklich ein wahrer Kommentar. Ich muss echt weblogs.asp.net   haufiger lesen                    

# August 1, 2011 12:44 AM

Genf20 Plus reviews said:

Danke, nun endlich habe ich dies in der Tiefe begriffen ;-)                      

# December 12, 2011 2:40 AM

Genf20 Plus reviews said:

Danke, nun endlich habe ich dies in der Tiefe begriffen ;-)                      

# December 12, 2011 2:43 AM