Get the all the values of DisplayName attributes

Question

I'm using asp.net MVC 5 with EntityFramework 6 DataAnnotations. I would like to know if there is a way to get all DisplayName of an object and save them in a variable into a Controller class.

For example, considering the class:

public class Class1
{
    [DisplayName("The ID number")]
    public int Id { get; set; }

    [DisplayName("My Value")]
    public int Value { get; set; }

    [DisplayName("Label name to display")]
    public string Label { get; set; }
}

How to get the values of DisplayName for all attributes? For example how to create a function that returns a Dictionary< string,string > which has a key with attribute name and value with DisplayName, like this:

{ "Id": "The ID name", "Value": "My Value", "Label": "Label name to display"}.

I have seen this topic stackoverflow - get the value of DisplayName attribute but I have no ideas of a way to extends this code.

`DisplayName` or `Display` (they are different)? – Ivan Stoev Dec 15 '16 at 14:24 — Ivan Stoev, Dec 15 '16 at 14:24

score 5 · Accepted Answer · answered Dec 15 '16 at 14:41

5

If you don't really care for the DisplayName attribute, but the effective display name that will be used (for instance by data binding), the easiest is to use TypeDescriptor.GetProperties method:

var info = TypeDescriptor.GetProperties(typeof(Class1))
    .Cast<PropertyDescriptor>()
    .ToDictionary(p => p.Name, p => p.DisplayName);

answered Dec 15 '16 at 14:41

Ivan Stoev

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Thank you for the answer. I have encapsulated your code for working with Generic Class and it continue to works. You solve my problem! – Cyr Dec 15 '16 at 15:16
Would it be possible to get a dictionary with the values of the display names and a reference to the function itself? Even if this is only possible for static methods. – Reiner Sep 01 '17 at 08:57
@Reiner Not sure I follow, can you give an example? – Ivan Stoev Sep 01 '17 at 09:19
Lets assume that that the `[DisplayName("The ID number")] public static int Id { get; set; }` method would be added into a dictionary `Dictionary` as entry object: `{"The ID number", Class1.Id}` and could be used with `int id = dic["The ID number"]` – Reiner Sep 01 '17 at 09:45
@Reiner So you want a dictionary with display name being a key, and value being... hmm, not sure what. Most likely what you need is possible, but consider posting your own question with the specific requirement. – Ivan Stoev Sep 01 '17 at 13:09

Dhanashree · Answer 2 · 2016-12-15T16:16:27.280

0

You can use the code below -

 Class1 c = new Class1();
 PropertyInfo[] listPI = c.GetType().GetProperties();
 Dictionary<string, string> dictDisplayNames = new Dictionary<string, string>();
 string displayName = string.Empty;

 foreach (PropertyInfo pi in listPI)
 {
    DisplayNameAttribute dp = pi.GetCustomAttributes(typeof(DisplayNameAttribute), true).Cast<DisplayNameAttribute>().SingleOrDefault();
            if (dp != null)
            {
                displayName = dp.DisplayName;
                dictDisplayNames.Add(pi.Name, displayName);
            }
 }

I have also referred to same link that you have mentioned in the question.

the final dictionary is as -

edited Dec 15 '16 at 16:16

answered Dec 15 '16 at 14:55

Dhanashree

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Thank you for the answer but unfortunately your code doesn't work on my project. – Cyr Dec 15 '16 at 15:44
what is the issue? – Dhanashree Dec 15 '16 at 15:45
It returns "Sequence contains no elements" in the displayName assignment into the foreach loop. – Cyr Dec 15 '16 at 15:48
Oh! sorry @Cyr there was a typo – Dhanashree Dec 15 '16 at 15:51
Oh! sorry @Cyr there was a typo, I have edited in the answer. It was inside the foreach loop - displayName = pi.GetCustomAttributes(typeof(DisplayNameAttribute), true).Cast().Single().DisplayName; – Dhanashree Dec 15 '16 at 15:52
Now it works. But if an attribute in the Model don't have the `[DisplayName("field name")]` DataAnnotation, it returns a System.InvalidOperationException (due to empty sequence). – Cyr Dec 15 '16 at 16:11
Then you have to add code to check if the attribute is null. I have edited the answer accordingly. – Dhanashree Dec 15 '16 at 16:17

Get the all the values of DisplayName attributes

2 Answers2