What is difference between File.Exists("") and FileInfo exists

Question

I have an *.exe file in \ProgramFiles(x86)\MyAppFolder.

In x86 application I check if the file exists (64 bit system). simple:

bool fileExists = File.Exists(@"\ProgramFiles(x86)\MyAppFolder\Manager.exe");

The result is: "fileExists == false" (the file is really there). It's Virtualization as I understand.That issue described here Its ok. But next code:

bool fileExists = new FileInfo("\\Path").Exists;

"fileExists == true"

Why is the result different in 1st and 2nd cases?

var controller = new ServiceController(Product.ServiceName);
_manager.Enabled = controller.Status == ServiceControllerStatus.Running;

var info = new DirectoryInfo(Assembly.GetExecutingAssembly().Location);

var s = File.Exists(@"D:\TFS\GL_SOURCES\Teklynx_LPM\Dev\Server\Debug\Manager.exe");

string pathToManager = string.Empty;

if (info.Parent != null)
{
    var pathToModule = info.Parent.FullName;
    pathToManager = Path.Combine(pathToModule,"Manager.exe").Replace(" ",string.Empty);
}

//works good

var fileInfo = new FileInfo(pathToManager);
var managerSeparator = new ToolStripSeparator()
{
    Visible = _manager.Visible = fileInfo.Exists // true
};

//Does not work

var managerSeparator = new ToolStripSeparator()
{
    Visible = _manager.Visible = File.Exists(pathToManager ) // false
};

Thanks!

Answer 1

There is no difference, these methods use the exact same internal helper method inside the .NET Framework. Something you can see with a decompiler or the Reference Source source code, the helper method name is File.FillAttributeInfo().

Having duplication like this in the .NET Framework is pretty unusual, not exactly a Good Thing to have more than one way to accomplish the same thing. The File class is however special, it got added after a usability study conducted when .NET 1.0 shipped. The test subjects just had the basic BCL classes to work with, like FileStream and FileInfo, and otherwise only had MSDN documentation available. The test results were not very good, the File class got added to help programmers fall in the pit of success writing very basic file manipulation code. Like File.Exists() and File.ReadAllLines().

So it doesn't have anything to do with the classes, you are just using them wrong. Like not actually using the same path. Do go easy on the forward slashes, the mapping to backward slashes happens inside Windows and is inconsistently implemented in other code. Using // certainly doesn't do what you hope it does.