As others have noted, you cannot have a field of “ref to variable” type. However, just knowing that you cannot do it is probably unsatisfying; you probably also want to know first, why not, and second, how to get around this restriction. The reason why is because there are only three possibilities: 1) Disallow fields … Read more
Fields and properties look the same, but they are not. Properties are methods and as such there are certain things that are not supported for properties, and some things that may happen with properties but never in the case of fields. Here’s a list of differences: Fields can be used as input to out/ref arguments. … Read more
You can: typeof(Foo) .GetField(“bar”,BindingFlags.Instance|BindingFlags.NonPublic) .SetValue(foo,567);
Entities (packages, types, methods, variables, etc.) defined in a Java program have names. These are used to refer to those entities in other parts of a program. The Java language defines a scope for each name The scope of a declaration is the region of the program within which the entity declared by the declaration … Read more
Ladislav’s answer updated to use DbContext (introduced in EF 4.1): public void ChangePassword(int userId, string password) { var user = new User() { Id = userId, Password = password }; using (var db = new MyEfContextName()) { db.Users.Attach(user); db.Entry(user).Property(x => x.Password).IsModified = true; db.SaveChanges(); } }
The transient keyword in Java is used to indicate that a field should not be part of the serialization (which means saved, like to a file) process. From the Java Language Specification, Java SE 7 Edition, Section 8.3.1.3. transient Fields: Variables may be marked transient to indicate that they are not part of the persistent … Read more
As pointed out in this answer, Django 1.9 added the Field.disabled attribute: The disabled boolean argument, when set to True, disables a form field using the disabled HTML attribute so that it won’t be editable by users. Even if a user tampers with the field’s value submitted to the server, it will be ignored in … Read more
In a related question I had some time ago, there was a link to a posting on Jeff’s blog, explaining some differences. Properties vs. Public Variables Reflection works differently on variables vs. properties, so if you rely on reflection, it’s easier to use all properties. You can’t databind against a variable. Changing a variable to … Read more
In order to access private fields, you need to get them from the class’s declared fields and then make them accessible: Field f = obj.getClass().getDeclaredField(“stuffIWant”); //NoSuchFieldException f.setAccessible(true); Hashtable iWantThis = (Hashtable) f.get(obj); //IllegalAccessException EDIT: as has been commented by aperkins, both accessing the field, setting it as accessible and retrieving the value can throw Exceptions, … Read more
Binding generally doesn’t work to fields. Most binding is based, in part, on the ComponentModel PropertyDescriptor model, which (by default) works on properties. This enables notifications, validation, etc (none of which works with fields). For more reasons than I can go into, public fields are a bad idea. They should be properties, fact. Likewise, mutable … Read more