Checking out Jouni Heikniemi’s excellent map of What’s new in .NET 4.5 I spotted this comment:

Methods can access call site info as parameter (CallerInfo)

Intrigued, some google-fu revealed that Anders Hejlberg demoed this in his session at build - new attributes [CallerFilePath], [CallerLineNumber] and [CallerMemberName], available for use on method parameters and automatically filled in by the compiler.

The immediate use that springs to mind is for the implementation of the INotifyPropertyChanged interface:

public string Name
{
    get { return mName; }
    set {
        if (!Equals(mName, value)) {
            mName = value;
            OnNotifyPropertyChanged();
        }
    }
}

protected void OnNotifyPropertyChanged(
    [CallerMemberName] string propertyName = "")
{
    ... 
}

Note how we no longer need to pass the name of the property as a magic string to OnNotifyPropertyChanged() because the compiler will fill it in for us.

I’m sure there’ll be more inventive uses though …

Comments

blog comments powered by Disqus
Next Post
A story about Magic  10 Dec 2011
Prior Post
NUnit to the Rescue  01 Dec 2011
Related Posts
Extension Methods  19 Jan 2019
Generating Hash Codes  12 Jan 2019
The Problem with Equality  05 Jan 2019
Queue Equality  29 Dec 2018
Smarter Queue Enumeration  22 Dec 2018
Queue Enumeration  15 Dec 2018
Queue Testing  08 Dec 2018
Creating Branching Nodes  01 Dec 2018
Two Dual Item Queues  24 Nov 2018
Simple Queues  17 Nov 2018
More csharp posts »
Archives
December 2011
2011