Tag Archives: Visual-Studio

Visual Studio smart replace

Let’s say you need to replace an expression in many files in Visual Studio with another expression. The case in question is replacing

nameof(someVariable)
to
"someVariable"

Sure you can try to replace

nameof(
to
"

but this will leave the double quote open and we don’t want this. Searching on the internetz and finding some stackoverflow solution and with the help of a second pair of eyes from a colleague we managed to find a solution like so:

Hit CTRL-SHIFT-H in Visual Studio and check “Use Regular Expressions”. Then select your scope, for example “Entire solution” and use the following expressions:

Find what:
nameof\(([a-zA-z]+)\)

Replace with:
"$1"

This will do the job. Let’s analyze the expressions a bit. The “Find what:” one, first. ‘nameof’ is the literal occurence of ‘nameof’. The first round bracket is preceded by backslash because we need to escape it. This is because the round bracket is used in the regular expressions syntax while in our case we need to literally find it. This was the ‘\(‘ part.

Now there is the ‘([a-zA-z]+)’ part. This has several sub-parts. The round brackets mean that the whole segment should be captured. We’ll later see why and what this is. Next, the square bracket part means that this should match any letter be it uppercase or lowercase (yes, I didn’t handle digits or underscores etc. which may be used in parameter/variable names, that is left as an exercise to the reader :P ). The plus sign means the square bracket part may occur multiple times. This means that a parameter/variable name may have more than one such character. Finally we close this part with the round bracket.

The final part in the “Find what:” expression is a literal closing round bracket which, again, is escaped by being prefixed with a backslash.

In the “Replace with:” expression, the captured part in the previous expression (what is enclosed in the regular-expression-syntax round brackets) is expressed as $1, as first numbered. Finally we enclose this in double quotes because that is what we need.

As for why I had to rollback from C# 6 nameof expression to a stringly-typed version, that’s a story for another time, I guess.

Some more Android development peculiarities

There is a baked in logging class called, intuitively, Log. For some strange reason the authors chose to name its methods, most of them, with one letter. That is :

Log.d(..); // debug level
Log.e(..); // error level
...

Until you hit

...
Log.wtf(..);
...

This one’s funny and I appreciate their sense of humor as it goes up to renaming WTF to “What a Terrible Failure”. Like we’re so dumb that we can’t figure what they really had in mind :P

Another peculiarity is that in an activity (this akin to a Page / Form / whatever) you have some methods that you can/should override such as onCreate(). Everywhere is stated that the first thing you should write in the overriding method is a call to the super (that is base) class’s method. If it is really all that important and vital why didn’t the class designers go with a template method in first place?

That is a design pattern, that in this case, would go like so :

public class Activity {

    // ...

    private void onCreateInternal(Bundle savedInstanceState) {
        //vital stuff
        onCreate(savedInstanceState);
    }

    protected void onCreate(Bundle savedInstanceState) {
    }

    // ...

}

Take note of another difference between C# and Java : the methods and classes are virtual/unsealed by default. So the onCreate method in my example above is overrideable in any subclass. Also in Java terminology the base class is called the superclass.

Other differences of terminology include :

  • A namespace is called a package
  • By default an import (which is akin to a using directive) imports by default just the specified type and not the whole package (namespace). You need to use a wildcard to import the whole package
  • The closest thing to an assembly is called a JAR (Java ARchive).
  • Eclipse by default is set to autocompile. That is whenever you hit CTRL-S (Save) to a Java file the project is (re)compiled. This sounds terrible but it isn’t! You can’t even notice. Either there is an incremental compilation either the performance of the compiler is incredible.
  • Unlike Visual Studio, Eclipse presents the import block collapsed by default. I wish I had this in VS… Just like a mobile app fan would say “there’s an app for that”, I bet for VS “there’s a plugin for that” :P
  • In Java if you want to call the super (base) class’s constructor from the current class’s constructor you will write “super(…);” in the constructor’s body. When I first saw this I said to myself Fu-Kin-Su-Pa (er… “great”, that is). “Now I have the liberty to call the base/super constructor from wherever inside the constructor I want”. Well, no. It’s either the first line or it isn’t.

Well, I’ll rant more as I go learning Android development.

My goal is to get to know enough so I can do it in Xamarin via C# but first I must understand the underlying things in order to go a level of abstraction above.

In the next episode(s) : I am indebted with a follow-up from my presentation held at RONUA last year.

ReSharper hidden features – Generate Delegating Members

A frequently-used design pattern is the Decorator. This is also known as a mixin (or they might not be the very same thing but certainly they are related).

Typically you might need to create a class that implements a certain interface and uses another class that implements that exact interface but you need to provide some additional feature(s). An example would be a class that adds transactional behavior to an existing data-access class (a naive example) :


public interface IDataAccess
{
    void AddCustomerInvoice(Invoice invoice, User user);
}

public class DataAccess : IDataAccess
{
    public void AddCustomerInvoice(Invoice invoice, User user)
    {
        InsertInvoice(invoice, user);
        UpdateCustomerDebt(user, invoice.Total);
    }

    // ... the rest of the implementation
}

public class TransactionalDataAccess : IDataAccess
{
    private readonly IDataAccess _dataAccess;

    public TransactionalDataAccess(IDataAccess dataAccess)
    {
        if (dataAccess == null)
        {
            throw new ArgumentNullException();
        }
        _dataAccess = dataAccess;
    }

    public void AddCustomerInvoice(Invoice invoice, User user)
    {
         using(var tx = new TransactionScope())
         {
             _dataAccess.AddCustomerInvoice(invoice, user);
             tx.Complete();
         }
    }

    // ... the rest of the implementation
}

Another type of example would be the Adapter design pattern. An example would be providing access to a (static) class (that may be out of your control) in a mock-able manner. That is, implement another class, non-static, which implements a defined interface and eases unit-testing :

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