ReSharper and var [duplicate]

Resharper is primarily concerned with helping you refactor code, and the var keyword generally makes refactoring easier. For example, if the return values of any of those functions ever change to a compatibile type, you don't have to change any of this code. It's therefore now a little easier to refactor your tabCaseNotes type, for example.

Personally, I'm often inclined to leave your first two lines alone, because I like to see the type name for a variable explicitly listed somewhere on the line where the variable is declared. If anything, I might look for an interface to use instead, so that I also gain the same "generic-ness" as with the var keyword without losing any important readable type information. However, I would definitely use var for fillBrush, textBrush, and sf.

You don't need to have the type in the line to make it more readable, its a matter of personal preference. I do like the var variation:

var currentTab = tabCaseNotes.TabPages[e.Index];
var itemRect = tabCaseNotes.GetTabRect(e.Index);
var fillBrush = new SolidBrush(Color.Linen);
var textBrush = new SolidBrush(Color.Black);
var sf = new StringFormat
   {
      Alignment = StringAlignment.Center,
      LineAlignment = StringAlignment.Center
   };

Update: I will add a controversial view on it. Unless I am reading code from a book, I don't usually care what's the specific type for understanding some lines of code I am reading. Consider the .GetTableRectangle(e.Index), for which you are not showing the code that operates on it:

var itemRect = tabCaseNotes.GetTableRectangle(e.Index);
//do some operations on itemRect

While reading that specific code I will get more to understand it from the operations on itemRect than from its type. It can be IRectangle, Rectangle, CustomRectangle, and still won't say much on what the code is doing with it. Instead I care more for the itemRect.Height, itemRect.Width or itemRect.GetArea() along with the logic involved.

Update 2: As others have pointed out you can turn it off. Make sure to keep the team with the same practices, or you will probably end up with making changes one way or the other each time a different person touches the code. See: http://www.jetbrains.com/resharper/features/codeTemplate.html

Resharper doesn't want you to use var, it is giving you the option. If you do use var it will then give you the option to use an explicit type, so you can't win:-).

EDIT - interesting link discussing the topic.

It seems it can be turned off, go to Resharper -> Options -> Code Inspection -> Inspection Severity and scroll down a little to see the options related to var.

Resharper thinks it is best-practice, but some people disagree as you have read in the linked post. I like to use explicit declaration for increased readability, but to each their own. If you want to use explicit declaration, you can disable the rule in Resharper.