readonly

Today I found an article where a const field is called compile-time constant while a readonly field is called runtime constant . The two phrases come from 《Effective C#》. I searched in MSDN and the language spec, find nothing about runtime constant . No offensive but I don't think runtime constant is a proper phrase. private readonly string foo = "bar"; creates a variable named "foo", whose value is "bar", and the value is readonly, here it is a variable, no business on constant . A readonly variable is still a variable, it can't be a constant. Variable and constant are mutually exclusive.

I'm trying to figure out how to map against a simple read-only property and have that property fire when I save to the database. A contrived example should make this more clear. First, a simple table: meta = MetaData() foo_table = Table('foo', meta, Column('id', String(3), primary_key=True), Column('description', String(64), nullable=False), Column('calculated_value', Integer, nullable=False), ) What I want to do is set up a class with a read-only property that will insert into the calculated_value column for me when I call session.commit()... import datetime def Foo(object): def __init__(self

Automatic properties let me replace this code: private MyType myProperty; public MyType MyProperty { get { return myPropertyField; } } with this code: public MyType MyProperty { get; private set; } with a few changes here and there - but is there a way to replace this code: private readonly MyType myProperty; public MyType MyProperty { get { return myPropertyField; } } with something similar? No, but this idea is being tracked on Connect . Indeed, there is no way to do this at present. We realize that in C# 3 we produced a bit of a philosophical oxymoron. The design of LINQ is heavily steeped

So here's an excerpt from one of my classes: [ThreadStatic] readonly static private AccountManager _instance = new AccountManager(); private AccountManager() { } static public AccountManager Instance { get { return _instance; } } As you can see, it's a singleton-per-thread - i.e. the instance is marked with the ThreadStatic attribute. The instance is also instantiated as part of static construction. So that being the case, how is it possible that I'm getting a NullReferenceException in my ASP.NET MVC application when I try to use the Instance property? Quoting MSDN ThreadStaticAttribute : Do

I have a strongly-typed MVC View Control which is responsible for the UI where users can create and edit Client items. I'd like them to be able to define the ClientId on creation, but not edit, and this to be reflected in the UI. To this end, I have the following line: <%= Html.TextBox("Client.ClientId", ViewData.Model.ClientId, new { @readonly = (ViewData.Model.ClientId != null && ViewData.Model.ClientId.Length > 0 ? "readonly" : "false") } ) %> It seems that no matter what value I give the readonly attribute (even "false" and ""), Firefox and IE7 make the input read-only, which is annoyingly

I have a class Bar with a private field containing the reference type Foo . I would like to expose Foo in a public property, but I do not want the consumers of the property to be able to alter Foo ... It should however be alterable internally by Bar , i.e. I can't make the field readonly . So what I would like is: private _Foo; public Foo { get { return readonly _Foo; } } ...which is of course not valid. I could just return a clone of Foo (assumming that it is IClonable ), but this is not obvious to the consumer. Should I change the name of the property to FooCopy ?? Should it be a