استخدام Readonly و Constant في ال C# - نسخة قابلة للطباعة

كود :

// NOTE: This code snippet is designed for VS.NET 2005 or later.

public class Test

{

// Note that constants are static by default and readonly 

// variables are not.

// A constant, "Hello!", must be provided at the time the constant 

// is:

public const string Hello = "Hello!";

// This constant will also work:

public const int Number = 1;

// This will throw an exception because DateTime.Now is NOT a 

public constant public const DateTime Now = DateTime.Now;

// This constant will throw an error because it's not set:

public const short ShortNumber;

// A readonly, "Hey!", can be set at runtime or at declaration time 

// and doesn't need to be a literal value:

public readonly String Hey1 = "Hey!";

// Since a readonly variable doesn't need to be set at declaration 

// time, the following will work; variable Hey2 can be set ONLY in 

// the constructor of the class:

public readonly String Hey2;

// Unlike constant, readonly variables can have non-literal values:

public readonly DateTime RightNow = DateTime.Now;

}