R – What are the key features/benefits of RIA Services

netwcfwcf-ria-servicesweb services

I am currently researching .NET RIA Services however I am having trouble finding a definitive list of the benefits of RIA services compared to plain WCF to Silverlight, or event a list of the key components that make up RIA Services. I also find it hard to see where RIA services sits in the development model and exactly what it provides to the developer.

Are there any tangible benefits to using RIA as opposed to other options?
What are the key components that make up RIA services?
What can you do with RIA that you can't do with existing Microsoft / .NET technologies?

Best Answer

Brad Abrams has a series of posts about RIA Sevices, starting with What is .NET RIA Services?. MSDN also has an introduction.

However in summary, the proposition of RIA Services is that the framework code generates a client side layer from your server side (domain) layer. Consequently it exposes your entities client side and takes care of the networking (now using WCF).

Of course you could code this all yourself. The biggest gain with RIA Services is therefore time, providing you are happy to conform to how RIA Services does things.

I have used it for a Silverlight client and found it easy to use, with the necessity to write service layer plumbing taken care of by the framework.

This is the style that Microsoft tends to use in their examples.

It appears that the guidance in this area may have changed, as StyleCop now enforces the use of the C# specific aliases.

C# – the difference between const and readonly in C#

Apart from the apparent difference of

having to declare the value at the time of a definition for a const VS readonly values can be computed dynamically but need to be assigned before the constructor exits.. after that it is frozen.
const's are implicitly static. You use a ClassName.ConstantName notation to access them.

There is a subtle difference. Consider a class defined in AssemblyA.

public class Const_V_Readonly
{
  public const int I_CONST_VALUE = 2;
  public readonly int I_RO_VALUE;
  public Const_V_Readonly()
  {
     I_RO_VALUE = 3;
  }
}

AssemblyB references AssemblyA and uses these values in code. When this is compiled:

in the case of the const value, it is like a find-replace. The value 2 is 'baked into' the AssemblyB's IL. This means that if tomorrow I update I_CONST_VALUE to 20, AssemblyB would still have 2 till I recompile it.
in the case of the readonly value, it is like a ref to a memory location. The value is not baked into AssemblyB's IL. This means that if the memory location is updated, AssemblyB gets the new value without recompilation. So if I_RO_VALUE is updated to 30, you only need to build AssemblyA and all clients do not need to be recompiled.

So if you are confident that the value of the constant won't change, use a const.

public const int CM_IN_A_METER = 100;

But if you have a constant that may change (e.g. w.r.t. precision).. or when in doubt, use a readonly.

public readonly float PI = 3.14;

Update: Aku needs to get a mention because he pointed this out first. Also I need to plug where I learned this: Effective C# - Bill Wagner

Best Answer

Related Solutions

C# – the difference between String and string in C#

This is the style that Microsoft tends to use in their examples.

C# – the difference between const and readonly in C#

Related Topic