Get List if Properties of type ICollection from Generic Class

Question

I have an object that contains some ICollection type properties

So basically the class looks like this:

Class Employee {

public ICollection<Address> Addresses {get;set;}

public ICollection<Performance> Performances {get; set;}

}

The problem is get property names of type ICollection, inside of Generic class, by using reflection.

My Generic Class is

Class CRUD<TEntity>  {

public object Get() {
 var properties = typeof(TEntity).GetProperties().Where(m=m.GetType() == typeof(ICollection ) ... 
}

But it is not working.

How can I get a property here?

is the code compiling ?? because you have missed `>` operator in lamda expression — Rajeev Kumar, Jul 30 '14 at 08:58

score 8 · Accepted Answer · answered Jul 30 '14 at 09:01

GetProperties() returns a PropertyInfo[]. You then do a Where using m.GetType(). If we assume that you missed a >, and this is m=>m.GetType(), then you are actually saying:

 typeof(PropertyInfo) == typeof(ICollection)

(caveat: actually, it is probably a RuntimePropertyInfo, etc)

What you mean is probably:

typeof(ICollection).IsAssignableFrom(m.PropertyType)

However! Note that ICollection <> ICollection<> <> ICollection<Address> etc - so it isn't even that easy. You might need:

m.PropertyType.IsGenericType &&
    m.PropertyType.GetGenericTypeDefinition() == typeof(ICollection<>)

Confirmed; this works:

static void Main()
{
    Foo<Employee>();
}
static void Foo<TEntity>() {
    var properties = typeof(TEntity).GetProperties().Where(m =>
        m.PropertyType.IsGenericType &&
        m.PropertyType.GetGenericTypeDefinition() == typeof(ICollection<>)
    ).ToArray();
    // ^^^ contains Addresses and Performances
}

Thank you Marc, it works! Yes indeed I was getting RuntimePropertyInfo and I did exactly what you did but I don't know why it is different and probably because I was comparing with ICollection! — codebased, Jul 30 '14 at 11:28

score 2 · Answer 2 · answered Jul 30 '14 at 09:05

You can use IsGenericType and check GetGenericTypeDefinition against typeof(ICollection<>)

public object Get()
{
    var properties =
        typeof (TEntity).GetProperties()
            .Where(m => m.PropertyType.IsGenericType && 
                    m.PropertyType.GetGenericTypeDefinition() == typeof (ICollection<>));
}

Get List if Properties of type ICollection from Generic Class

2 Answers2

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