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How to iterate the List in Reflection

Tags:

c#

reflection

I am having one property called Students which is of type List<Student>.

In reflection i can get the value of Students Property.

Now the problem is How to iterate the List of Students.

I need to check whether StudentID [ some value ] is in that collection.

var collection = studentPro.GetValue(studentObj,null);

//I need to iterate like this,

foreach(var item in collection)
{
     if(item.StudentID == 33)
         //Do stuff
}

Please help me.

like image 453
Thaadikkaaran Avatar asked May 10 '11 12:05

Thaadikkaaran


3 Answers

You just need to cast it:

var collection = (List<Student>) studentPro.GetValue(studentObj,null);

The value returned to you and stored in var is of type object. So you need to cast it to List<Student> first, before trying looping through it.

RANT

That is why I personally do not like var, it hides the type - unless in VS you hover on it. If it was a declared with type object it was immediately obvious that we cannot iterate through it.


UPDATE

Yes its good. But casting should be done with reflection. In reflection we dont know the type of List. We dont know the actual type of the studentObj

In order to do that, you can cast to IEnumerable:

var collection = (IEnumerable) studentPro.GetValue(studentObj,null);
like image 74
Aliostad Avatar answered Nov 15 '22 06:11

Aliostad


Try this

IEnumerable<Student> collection = (IEnumerable<Student>)studentPro.GetValue(studentObj,null);
like image 44
Stecya Avatar answered Nov 15 '22 05:11

Stecya


Others have suggested casting to List but I will assume that this won't work for you... if you had access to the Student class, you wouldn't be using reflection to begin with. So instead, just cast to IEnumerable and then inside your loop, you'll have to use reflection again to access whatever properties you want off of each item in the collection.

var collection = (IEnumerable)studentPro.GetValue(studentObj,null)

like image 2
Robert Levy Avatar answered Nov 15 '22 04:11

Robert Levy