How to use an c# alias to save time writing commands

Matt Higgins

I've trying to create a shorter way to write - to save time :-

using wl = Debug.WriteLine;

I've declared this at the top of the project but I get a compile error. Can anyone tell me how to set the alias properly :-

Debug.WriteLine("");

I've like to be able to write such commands like this if possible:-

wl("");

Thanks

Matt

6 Replies

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Vulpes14y ago
Yes, but even if you call the extension method 'wl', you still have to use an object reference to call it.
Muhammad Imran14y ago
Sorry... you may use extension method instead...

using System.Collections.Generic;

        public static void ToDebug(this T obj)
        {
            System.Diagnostics.Debug.WriteLine(obj.ToString());
        }

you may call it as:
      string s="This is a text";
      s.ToDebug();

etc..
Vulpes14y ago
If you check out the Debug.WriteLine() method in the MSDN docs, you'll see that it has [ConditionalAttribute("DEBUG")] attached to it:

http://msdn.microsoft.com/en-us/library/9z9k5ydz.aspx

This means that the method should be ignored by the compiler unless the DEBUG conditional compilation symbol is defined. Now, the latter is dealt with automatically by Visual Studio when building a project in debug mode.

However, because the DEBUG symbol might not be there in a release build, the C# compiler won't let you create a delegate with this method (or any other method to which the Conditional attribute is used) which rules out assigning the method to a variable of a delegate type such as Action.

Even in cases where this is possible, I'm not keen on doing it anyway because it adds an extra field to the class and therefore increases the memory footprint of an object of that type on the heap. If you are going to use it, it's best to make it static so that there's only a single memory allocation for the class as a whole rather than one per instance.
Matt Higgins14y ago
Hi
This command looks good but it doesn't compile :-
Action wl = System.Diagnostics.Debug.WriteLine;

I get a compile error:-
Error 1 Cannot create delegate with 'System.Diagnostics.Debug.WriteLine(string)' because it has a Conditional attribute

Any idea why this error appears
Thanks
Matt
Muhammad Imran14y ago
Define this action at class level

Action wl = System.Diagnostics.Debug.WriteLine;

then use anywhere in that class...

wl("Your text here");
Vulpes14y ago
Whilst you can easily create a file-wide alias for a type:

using D = System.Diagnostics.Debug;

unfortunately, there's no way to create a file-wide alias for a method in C#.

You can effectively do it at type level e.g.

class MyClass
{
static void wl(string s)
{
Debug.WriteLine(s);
}

public void SomeOtherMethod(string s)
{
wl(s);
// ....
}

// ...
}

but it's tedious to do this in more than a couple of classes.