A field initializer cannot reference the nonstatic field, method, or property

Question

I have a class and when I try to use it in another class I receive the error below.

using System; using System.Collections.Generic; using System.Linq;  namespace MySite {     public class Reminders     {         public Dictionary<TimeSpan, string> TimeSpanText { get; set; }          // We are setting the default values using the Costructor         public Reminders()         {             TimeSpanText.Add(TimeSpan.Zero, "None");             TimeSpanText.Add(new TimeSpan(0, 0, 5, 0), "5 minutes before");             TimeSpanText.Add(new TimeSpan(0, 0, 15, 0), "15 minutes before");             TimeSpanText.Add(new TimeSpan(0, 0, 30, 0), "30 minutes before");             TimeSpanText.Add(new TimeSpan(0, 1, 0, 0), "1 hour before");             TimeSpanText.Add(new TimeSpan(0, 2, 0, 0), "2 hours before");             TimeSpanText.Add(new TimeSpan(1, 0, 0, 0), "1 day before");             TimeSpanText.Add(new TimeSpan(2, 0, 0, 0), "2 day before");         }      } } 

Using the class in another class

class SomeOtherClass {       private Reminders reminder = new Reminders();     // error happens on this line:     private dynamic defaultReminder = reminder.TimeSpanText[TimeSpan.FromMinutes(15)];      .... 

Error (CS0236):

A field initializer cannot reference the nonstatic field, method, or property 

Why does it happen and how to fix it?

Answer 1

This line:

private dynamic defaultReminder =                            reminder.TimeSpanText[TimeSpan.FromMinutes(15)]; 

You cannot use an instance variable to initialize another instance variable. Why? Because the compiler can rearrange these - there is no guarantee that reminder will be initialized before defaultReminder, so the above line might throw a NullReferenceException.

Instead, just use:

private dynamic defaultReminder = TimeSpan.FromMinutes(15); 

Alternatively, set up the value in the constructor:

private dynamic defaultReminder;  public Reminders() {     defaultReminder = reminder.TimeSpanText[TimeSpan.FromMinutes(15)];  } 

There are more details about this compiler error on MSDN - Compiler Error CS0236.