CODEWITHSUNDEEP
c#linqlistreflection
erosebe
erosebe

Reputation: 967

How to RemoveAll from list where any object property is null or empty?

I have an object with many properties. I create a list of these objects and weed out the bad ones by finding cases where an important property is null or empty. Like...

theList.RemoveAll(p => string.IsNullOrEmpty(p.ID));

How can I do a similar check but instead of checking a single property, check if any property in the object IsNullOrEmpty?

I've been working with Reflection to get things like

object x = typeof(MyObject).GetProperties().
    Select(p => p.GetValue(exampleObject, null)).
    Where(v => string.IsNullOrEmpty(v.ToString())));

but I don't grock it well enough to put it all together. Please set me straight.

Upvotes: 2

Views: 3444

Answers (2)

Sergey Berezovskiy
Sergey Berezovskiy

Reputation: 236218

Thus it makes sense to apply String.IsNullOrEmpty only to string values, you should select only properties of string type:

List<MyObject> objects = new List<MyObject>();
// fill list

var stringProperties = typeof(MyObject)
        .GetProperties()
        .Where(p => p.PropertyType == typeof(string))
        .ToArray();

And then get filtered sequence of objects:

var query = objects.Where(o =>
    stringProperties.All(p => !String.IsNullOrEmpty((string)p.GetValue(o))));

You can use same approach to remove objects from list:

objects.RemoveAll(o => 
     stringProperties.Any(p => String.IsNullOrEmpty((string)p.GetValue(o))));

WORKING SAMPLE

Upvotes: 2

L.B
L.B

Reputation: 116118

check if any property in the object IsNullOrEmpty?

theList.RemoveAll(x => x.GetType().GetProperties()
                                  .Select(p => p.GetValue(x, null))
                                  .Any(p => p == null));

Upvotes: 5

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