Illegal characters in path when calling the index

问题:

I am receiving an ArgumentException when invoking the index action of one of my controllers and I am not sure why. The error message is the following:

Server Error in '/' Application.

Illegal characters in path.

[ArgumentException: Illegal characters in path.]
 System.IO.Path.CheckInvalidPathChars(String path) +126
 System.IO.Path.Combine(String path1, String path2) +38

I am not sure why this is happening. here is the code from the controller:

    public ActionResult Index()
    {
        var glaccounts = db.GLAccounts.ToString();
        return View(glaccounts);
    }

回答1:

The ambiguity comes from the fact that you are using string as model type. This ambiguity could be resolved like this:

public ActionResult Index()
{
    var glaccounts = db.GLAccounts.ToString();
    return View((object)glaccounts);
}

or:

public ActionResult Index()
{
    object glaccounts = db.GLAccounts.ToString();
    return View(glaccounts);
}

or:

public ActionResult Index()
{
    var glaccounts = db.GLAccounts.ToString();
    return View("Index", glaccounts);
}

Notice the cast to object to pick the proper method overload as there is already a View method which takes a string argument which represents the view name so you cannot throw whatever you want to it => if it's a string it must be the name of the view and this view must exist.

回答2:

I found it finally. It is a really embarassing typo by me. I mistyped the code:

    public ActionResult Index()
    {
        var glaccounts = db.GLAccounts.ToString();
        return View(glaccounts);
    }

instead of:

    public ActionResult Index()
    {
        var glaccounts = db.GLAccounts.ToList();
        return View(glaccounts);
    }

Then the framework wanted to load a view file, like this:

"~/Views/GLAccount/SELECT \r\n[Extent1].[Id] AS [Id], \r\n[Extent1].[OrgDefinitionId] AS [OrgDefinitionId], \r\n[Extent1].[GLAccountId] AS 
[GLAccountId], \r\n[Extent1].[Name] AS [Name], \r\n[Extent1].[StartDate] AS [StartDate], 
\r\n[Extent1].[EndDate] AS [EndDate]\r\nFROM [GLAccounts] AS [Extent1].aspx"

Hopefully, I will save couple of hours of debugging for someone else by posting this :(