Adding nameof to C# through backdoors
Well, I am not alone who is being sick of magical strings which are constantly used just to do data binding -- see:
How to make Databinding type safe and support refactoring
However I am concerned with performance of this solution and much more typing -- each time you would like to use nameof you have to type a lambda. So I am thinking of more brute-force method -- writing a function nameof and external program, that will change each .cs file before it is compiled.
public string nameof<T>(T obj,string name = null)
{
return name;
}
You would use it this way
nameof(the_object.MyProperty);
The key lies in external program helping nameof -- it would search for any call of the nameof, and simply replace
nameof(X.Y.Z)
or
nameof(X.Y.Z,"s")
into
n开发者_如何转开发ameof(X.Y.Z,"Z")
My question is -- what limitations, pitfalls of this approach do you see? Or maybe .Net 5.0 with built-in nameof will be shipped next week, so it make no sense to start writing a program for it? ;-)
Thank you in advance for your thoughts, recommendations, and so on.
Doing any pre-compilation code changes would be an extreme hassle. So I would avoid it.
I wouldn't worry too much about performance - most times when you need a property name as a string you'll end up doing reflection or IO anyway, so performance is going to be relatively slow anyway.
Here's what I suggest to use:
public static string ToPropertyName<T>(this Expression<Func<T>> @this)
{
var @return = string.Empty;
if (@this != null)
{
var memberExpression = @this.Body as MemberExpression;
if (memberExpression != null)
{
@return = memberExpression.Member.Name;
}
}
return @return;
}
Now you can do this:
Expression<Func<T>> px = x => x.Foo;
var pn = px.ToPropertyName(); // == "Foo"
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