Named & optional parameters are a new C# language feature coming
up with .NET FX 4.0 and guess what… it’s in Silverlight 4 as well!
Optional
parameters will come very useful when defining complex APIs
where you would usually have to provide several overloads for the same
method for it to make sense to wide variety of usages. Let’s take a look
at this basic example:
public
void PositionWindow(bool isTopMost, double left = 0, double top = 0, double width = 800, double height = 600)
{
Window window =
Application.Current.MainWindow;
window.TopMost = isTopMost;
window.Left = left;
window.Top = top;
window.Width = width;
window.Height = height;
}
isTopMost is the only parameter that’s required, all other
parameter specify their default value, which makes them optional.
But what if you wanted to provide the size only and leave the position
to be set to defaults? Enter named parameters. The same
method above can be called also with:
PositionWindow(isTopMost:true, width: 600, height:
200);
PositionWindow(true, width: 600, height:
200);
PositionWindow(true, height: 200, width:
600);
PositionWindow(height:
200, width: 600, isTopMost: true);
Simple ... Cheers:)