Using PropertyInfo.GetValue()

Question

I have a class that creates a static array of all properties, using a static constructor. I also have a function -- GetNamesAndTypes() -- that lists the name & type of each property in that array.

Now I want to create another instance-level function -- GetNamesAndTypesAndValues() -- that displays the name & type of each property in the class, as well as that instance's value. How would I do that? Here's the code that I've written so far:

//StaticTest.cs using System; using System.ComponentModel; using System.Globalization; using System.Reflection;  namespace StaticTest {     public class ClassTest     {         private string m_A, m_B, m_C;         private static PropertyInfo[] allClassProperties;          static ClassTest()         {             Type type = typeof(ClassTest);             allClassProperties = type.GetProperties();              // Sort properties alphabetically by name              // (http://www.csharp-examples.net/reflection-property-names/)             Array.Sort(allClassProperties, delegate(PropertyInfo p1, PropertyInfo p2)             {                 return p1.Name.CompareTo(p2.Name);             });         }          public int A         {             get { return Convert.ToInt32(m_A); }             set { m_A = value.ToString(); }         }          public string B         {             get { return m_B; }             set { m_B = value; }         }          public DateTime C         {             get { return DateTime.ParseExact("yyyyMMdd", m_C,                                    CultureInfo.InvariantCulture); }             set { m_C = String.Format("{0:yyyyMMdd}", value); }         }          public static void GetNamesAndTypes()         {             foreach (PropertyInfo propertyInfo in allClassProperties)             {                 Console.WriteLine("{0} [type = {1}]", propertyInfo.Name,                                             propertyInfo.PropertyType);             }         }          public void GetNamesAndTypesAndValues()         {             foreach (PropertyInfo propertyInfo in allClassProperties)             {                 Console.WriteLine("{0} [type = {1}]", propertyInfo.Name,                                               propertyInfo.PropertyType);             }         }     } }  //Program.cs using System; using System.Collections.Generic; using StaticTest;  namespace ConsoleApplication2 {     class Program     {         static void Main(string[] args)         {             Console.WriteLine("[static] GetNamesAndTypes()");             ClassTest.GetNamesAndTypes();             Console.WriteLine("");              ClassTest classTest = new ClassTest();             classTest.A = 4;             classTest.B = @"bacon";             classTest.C = DateTime.Now;             Console.WriteLine("[instance] GetNamesAndTypesAndValues()");             classTest.GetNamesAndTypesAndValues();              Console.ReadLine();         }     } } 

I tried using propertyInfo.GetValue(), but I couldn't get it to work.

Answer 1

In your example propertyInfo.GetValue(this, null) should work. Consider altering GetNamesAndTypesAndValues() as follows:

public void GetNamesAndTypesAndValues() {   foreach (PropertyInfo propertyInfo in allClassProperties)   {     Console.WriteLine("{0} [type = {1}] [value = {2}]",       propertyInfo.Name,       propertyInfo.PropertyType,       propertyInfo.GetValue(this, null));   } }