Retrieve the names of all the boolean properties of a class which are true

Question

I have a class that has lots of bool properties. How can I create another property that is a list of strings that contains the name of the properties which have a value of true?

See initial attempt below - can't quite figure out how to filter the true ones

public class UserSettings
{
    public int ContactId { get; set; }
    public bool ShowNewLayout { get; set; }
    public bool HomeEnabled { get; set; }
    public bool AccountEnabled { get; set; }

    // lots more bool properties here

    public IEnumerable<string> Settings
    {
        get
        {
            return GetType()
                .GetProperties()
                .Where(o => (bool)o.GetValue(this, null) == true) //this line is obviously wrong
                .Select(o => nameof(o));
        }
    }
}

score 23 · Accepted Answer · edited Sep 19 '19 at 14:55

23

You can do it like this - all those properties that are of type bool and are true

public IEnumerable<string> Settings
{
    get
    {
        return GetType()
            .GetProperties().Where(p => p.PropertyType == typeof(bool) 
                                         && (bool)p.GetValue(this, null))
            .Select(p => p.Name);
    }
}

edited Sep 19 '19 at 14:55

AlexB

7,302
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answered Apr 24 '17 at 13:05

Nino

6,931
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Beat me to exactly the same answer. +1 – spender Apr 24 '17 at 13:08
Shouldn't it be `Select(o => o.Name)` instead of `nameof(o)`? – mrogal.ski Apr 24 '17 at 13:18
@m.rogalski to be honest, I just copied OP's `Select`. You're right, I'll edit my answer. – Nino Apr 24 '17 at 13:21

Adam Jachocki · Answer 2 · 2017-04-24T13:31:14.580

5

Without LINQ:

foreach (PropertyInfo propertyInfo in data.GetType().GetProperties())
{
    if (propertyInfo.PropertyType == typeof(bool))
    {
        bool value = (bool)propertyInfo.GetValue(data, null);

        if(value)
        {
           //add propertyInfo to some result
        }
    }
}

edited Apr 24 '17 at 13:31

answered Apr 24 '17 at 13:07

Adam Jachocki

1,897
1
12
28

You forgot to cast value to `bool` when assigning it from `GetValue(...)` method. – mrogal.ski Apr 24 '17 at 13:21

Retrieve the names of all the boolean properties of a class which are true

2 Answers2