C#
C#

Class Library Set Property / Field Default or Initial Values?

Q. How do I set the Property / Field Default or Initial values in a Class Library (.dll)?

I've read about Attributes and it doesn't seem the best approach. The example below is a simple illustration of properties/fields which need to be used, but don't neccessarilly need user setup. Note: it'a a static class.

public static class FtpClient
    {
         private static bool _useBinary = false;

         public static bool UseBinary
         {
              set { _useBinary = value; }
          }
     }

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pointemanAsked: 2012-12-27

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LVL 75

käµfm³d 👽Connect With a Mentor Commented: 2012-12-27

Well as I mentioned, what you have shown is a viable approach. You could also define a static constructor (if you so desired), but its net effect would be the same as what you are currently doing.

e.g.

...

    static FtpClient()
    {
        _useBinary = false;
    }

...

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Note: A static constructor isn't called directly. It will be invoked automatically the moment you refer to any of the class' static members or the first time you create an instance of class (if that class is non-static). The initialization you have shown above is also executed in this manner.

LVL 75

käµfm³d 👽Connect With a Mentor Commented: 2012-12-27

That would work (should work for a non-static class [and members] as well). Standard OO practices typically have you initialize a class within its constructor. .NET has something called "object initialization", which can substitute for a equivalent constructor or the approach above. Object initialization does not work with static code, however. Object initialization looks like this:

class Foo
{
    public string Message { get; set; }
}

class Program
{
    static void Main()
    {
        Foo f = new Foo()
        {
            Message = "Hello World!";
        };
    }
}

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The braces and the assignment of "Hello World!" to the Message property denote object initialization. Any non-static property can be initialized in this fashion.

I'm not sure how Attributes would help you here. There is a DefaultValueAttribute class, but it is more for code generators than for actual runtime code. This attribute will not set a default value for your objects at runtime.