C#: How to get all public (both get and set) string properties of a type

Question

I am trying to make a method that will go through a list of generic objects and replace all their properties of type string which is either null or empty with a replacement.

How is a good way to do this?

I have this kind of... shell... so far:

public static void ReplaceEmptyStrings<T>(List<T> list, string replacement) {     var properties = typeof(T).GetProperties( -- What BindingFlags? -- );      foreach(var p in properties)     {         foreach(var item in list)         {             if(string.IsNullOrEmpty((string) p.GetValue(item, null)))                 p.SetValue(item, replacement, null);         }     } } 

So, how do I find all the properties of a type that are:

• Of type string

• Has public get

• Has public set

  ?

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I made this test class:

class TestSubject {     public string Public;     private string Private;      public string PublicPublic { get; set; }     public string PublicPrivate { get; private set; }     public string PrivatePublic { private get; set; }     private string PrivatePrivate { get; set; } } 

The following does not work:

var properties = typeof(TestSubject)         .GetProperties(BindingFlags.Instance|BindingFlags.Public)         .Where(ø => ø.CanRead && ø.CanWrite)         .Where(ø => ø.PropertyType == typeof(string)); 

If I print out the Name of those properties I get there, I get:

PublicPublic PublicPrivate PrivatePublic

In other words, I get two properties too much.

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Note: This could probably be done in a better way... using nested foreach and reflection and all here... but if you have any great alternative ideas, please let me know cause I want to learn!

Answer 1

Your code rewritten. Does not use LINQ nor var.

public static void ReplaceEmptyStrings<T>(List<T> list, string replacement) {     PropertyInfo[] properties = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);      foreach (PropertyInfo p in properties)     {         // Only work with strings         if (p.PropertyType != typeof(string)) { continue; }          // If not writable then cannot null it; if not readable then cannot check it's value         if (!p.CanWrite || !p.CanRead) { continue; }          MethodInfo mget = p.GetGetMethod(false);         MethodInfo mset = p.GetSetMethod(false);          // Get and set methods have to be public         if (mget == null) { continue; }         if (mset == null) { continue; }          foreach (T item in list)         {             if (string.IsNullOrEmpty((string)p.GetValue(item, null)))             {                 p.SetValue(item, replacement, null);             }         }     } }