readonly

Arrays are a fast way to iterate through an unordered set of items, and it's often nice for them to be read-only. While exposing arrays with the `readonly' keyword is useless because the contents of the array can still be altered, a ReadOnlyCollection<T> wrapper solves this. The problem is it's 4 times slower than a plain array in tests I've done. (I know, returning a copy of the array would only take a performance hit once, but ideally I wouldn't want to waste CPU time on that either.) I have noticed I can get the benefit of a read-only sanity-check while preserving the performance of a plain

I have a class that defines a read-only property that effectively exposes a private field, something like this: public class Container { private List<int> _myList; public List<int> MyList { get { return _myList;} } public Container() : base () { _myList = new List<int>(); } // some method that need to access _myList public SomeMethod(int x) { _myList.Add(x); } } now it's impossible for the consumer to manage my property directly, so code like aContainer.MyList = new List(); generates a compile-time error. However, the consumer is absolutely free to call all sorts of methods on the reference he

We have a Java application with a particular module that checks if a temporary directory is 'writable' before executing its function. To test this, we have a JUnit test that creates a new directory, uses the Java File class method setWritable(false) to make the directory "not writable", then passes that directory to the module being tested and expects to get an IllegalArgumentException back. This had all been working fine for a long time under JDK 6u18. Today I have updated the JDK version to JDK 6u24 (the current release from the Sun site as of today). That unit test just started failing with

I use protobuf-net to serialize/deserialize my data. I have some rather simple classes, so that's no real problem. As far as I know, protobuf-net uses IL generation to create serialization/deserialization code. While I have readonly fields in my model, I wonder how is it possible to write to such a field with IL? I can plainly see it works well, but I don't know why... I've tried to spy it in the code, but it's a bit too complicated. My attempts to generate such code myself always result in IL validator errors. Actually, I can't get it to fail - at least, when generating in memory. Let's start

Update : This question has been revised to make it clearer. The answers below seem to reflect that this method works well. Hopefully this question can help people who need to add a get or set to an existing property. Ran into a problem today where I needed to override a base class's get -only property with both a get and set . Current consensus seems to be that this is impossible, but I think that I found a method. The general idea is to make a new property instead of directly override ing the old one, then we create a bridge method that override s the old get method with a call to the new one

Does C# allow a variable that can't be modified? It's like a const , but instead of having to assign it a value at declaration, the variable does not have any default value, but can only be assigned a value once at runtime (EDIT: and possibly not from constructor). or is this not possible? You could create your own generic class that provided this functionality, but that might be overkill. public class SetValueOnce<T> { public bool _set; private T _value; public SetValueOnce() { _value = default(T); _set = false; } public SetValueOnce(T value) { _value = value; _set = true; } public T Value {

How do you set the Textbox read only property to true or false using JavaScript in ASP.NET? Sridhar You can try document.getElementById("textboxid").readOnly = true; document.getElementById('textbox-id').readOnly=true should work Try This :- set Read Only False ( Editable TextBox) document.getElementById("txtID").readOnly=false; set Read Only true(Not Editable ) var v1=document.getElementById("txtID"); v1.setAttribute("readOnly","true"); This can work on IE and Firefox also. I find that document.getElementById('textbox-id').readOnly=true sometimes doesn't work reliably. Instead, try: document