How to get the list of properties of a class?


Question

How do I get a list of all the properties of a class?

1
548
6/16/2013 8:37:05 AM

Exper Answer

Reflection; for an instance:

obj.GetType().GetProperties();

for a type:

typeof(Foo).GetProperties();

for example:

class Foo {
    public int A {get;set;}
    public string B {get;set;}
}
...
Foo foo = new Foo {A = 1, B = "abc"};
foreach(var prop in foo.GetType().GetProperties()) {
    Console.WriteLine("{0}={1}", prop.Name, prop.GetValue(foo, null));
}

Following feedback...

  • To get the value of static properties, pass null as the first argument to GetValue
  • To look at non-public properties, use (for example) GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance) (which returns all public/private instance properties ).
735
1/20/2012 7:46:46 PM

You can use Reflection to do this: (from my library - this gets the names and values)

public static Dictionary<string, object> DictionaryFromType(object atype)
{
    if (atype == null) return new Dictionary<string, object>();
    Type t = atype.GetType();
    PropertyInfo[] props = t.GetProperties();
    Dictionary<string, object> dict = new Dictionary<string, object>();
    foreach (PropertyInfo prp in props)
    {
        object value = prp.GetValue(atype, new object[]{});
        dict.Add(prp.Name, value);
    }
    return dict;
}

This thing will not work for properties with an index - for that (it's getting unwieldy):

public static Dictionary<string, object> DictionaryFromType(object atype, 
     Dictionary<string, object[]> indexers)
{
    /* replace GetValue() call above with: */
    object value = prp.GetValue(atype, ((indexers.ContainsKey(prp.Name)?indexers[prp.Name]:new string[]{});
}

Also, to get only public properties: (see MSDN on BindingFlags enum)

/* replace */
PropertyInfo[] props = t.GetProperties();
/* with */
PropertyInfo[] props = t.GetProperties(BindingFlags.Public)

This works on anonymous types, too!
To just get the names:

public static string[] PropertiesFromType(object atype)
{
    if (atype == null) return new string[] {};
    Type t = atype.GetType();
    PropertyInfo[] props = t.GetProperties();
    List<string> propNames = new List<string>();
    foreach (PropertyInfo prp in props)
    {
        propNames.Add(prp.Name);
    }
    return propNames.ToArray();
}

And it's just about the same for just the values, or you can use:

GetDictionaryFromType().Keys
// or
GetDictionaryFromType().Values

But that's a bit slower, I would imagine.


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