No accessible overloaded

T

tshad

I am getting the following error which makes no sense. I am doing this in
asp.net. I get the following error:

No accessible overloaded

If you look at the error, there is one overloaded function that can be
called (int, string, int, int).

The first variable is constant that should work fine as an int and works
everywhere else.
The second variable is a string.
The third variable is a System.Int32. (from trace)
The fourth variable is a System.Int64. (from trace)

The code:
******************************************************
trace.warn("type = User - " & Session("User").UserID.GetType.ToString())
trace.warn("type = ApplicantID - " &
Session("ApplicantID").GetType.ToString())
HistoryLog.WriteHistoryLog(13,"Application Filed for: " &
HeaderJobTitle.Text,Session("User").UserID,session("ApplicantID"))
************************************************************

Trace results:
**************************
type = User - System.Int32
type = ApplicantID - System.Int64
****************************

It turns out if I change the above code to:

HistoryLog.WriteHistoryLog(13,"Application Filed for: " &
HeaderJobTitle.Text,Session("User").UserID,Convert.ToInt32(session("ApplicantID")))

I thought that the different sizes of integers were interchangeable
(obviously the conversion works OK). I would have thought that an Int64
would work fine for an Integer field.

The error messages:
********************************************************
Unhandled Execution Error

No accessible overloaded 'HistoryLog.WriteHistoryLog' can be called with
these arguments without a narrowing conversion:
Public Sub WriteHistoryLog ( ByVal historyActionID As Integer, ByVal detail
As String, ByVal userID As Integer, ByVal applicantID As Integer )
Public Sub WriteHistoryLog ( ByVal historyActionID As Integer, ByVal detail
As String, ByVal firstName As String, ByVal lastName As String )
at
Microsoft.VisualBasic.CompilerServices.VBBinder.set_InternalThrow(Exception
Value)
at Microsoft.VisualBasic.CompilerServices.VBBinder.BindToMethod(BindingFlags
bindingAttr, MethodBase[] match, Object[]& args, ParameterModifier[]
modifiers, CultureInfo culture, String[] names, Object& ObjState)
at Microsoft.VisualBasic.CompilerServices.VBBinder.InvokeMember(String name,
BindingFlags invokeAttr, Type objType, IReflect objIReflect, Object target,
Object[] args, ParameterModifier[] modifiers, CultureInfo culture, String[]
namedParameters)
at
Microsoft.VisualBasic.CompilerServices.LateBinding.InternalLateCall(Object
o, Type objType, String name, Object[] args, String[] paramnames, Boolean[]
CopyBack, Boolean IgnoreReturn)
at Microsoft.VisualBasic.CompilerServices.LateBinding.LateCall(Object o,
Type objType, String name, Object[] args, String[] paramnames, Boolean[]
CopyBack)
at ASP.applicationCompletedView_aspx.SubmitIt_Click(Object s,
ImageClickEventArgs e) in
C:\Inetpub\wwwroot\staffingworkshop\applicant\secure\applicationCompletedView.aspx:line
666
at System.Web.UI.WebControls.ImageButton.OnClick(ImageClickEventArgs e)
at
System.Web.UI.WebControls.ImageButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String
eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler
sourceControl, String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
at System.Web.UI.Page.ProcessRequestMain()
*******************************************************************

Here is the Function Call that is being called

Public Shared sub WriteHistoryLog (historyActionID as Integer,detail as
String,userID as Integer,applicantID as Integer)

Why doesn't this work with the convert function?

Thanks,

Tom
 
L

Larry Lard

tshad said:
I am getting the following error which makes no sense. I am doing this in
asp.net. I get the following error:

No accessible overloaded

If you look at the error, there is one overloaded function that can be
called (int, string, int, int).

In this group we would prefer to say (Integer, String, Integer,
Integer), but we know what you mean.
The first variable is constant that should work fine as an int and works
everywhere else.

Well, if it's a constant that the compiler thinks looks like an Integer,
yes.
The second variable is a string.
The third variable is a System.Int32. (from trace)
The fourth variable is a System.Int64. (from trace)
Aha.


The code:
******************************************************
trace.warn("type = User - " & Session("User").UserID.GetType.ToString())
trace.warn("type = ApplicantID - " &
Session("ApplicantID").GetType.ToString())
HistoryLog.WriteHistoryLog(13,"Application Filed for: " &
HeaderJobTitle.Text,Session("User").UserID,session("ApplicantID"))
************************************************************

Trace results:
**************************
type = User - System.Int32
type = ApplicantID - System.Int64
****************************

It turns out if I change the above code to:

HistoryLog.WriteHistoryLog(13,"Application Filed for: " &
HeaderJobTitle.Text,Session("User").UserID,Convert.ToInt32(session("ApplicantID")))

It works, I presume.
I thought that the different sizes of integers were interchangeable
(obviously the conversion works OK). I would have thought that an Int64
would work fine for an Integer field.

What would you like to happen if session("ApplicantID") happened to be
ten billion (which doesn't fit in an Integer) ?
The error messages:
********************************************************
Unhandled Execution Error

No accessible overloaded 'HistoryLog.WriteHistoryLog' can be called with
these arguments without a narrowing conversion:

As it turns out, the full error message does tell you exactly what the
problem is...
*******************************************************************

Here is the Function Call that is being called

Public Shared sub WriteHistoryLog (historyActionID as Integer,detail as
String,userID as Integer,applicantID as Integer)

Why doesn't this work with the convert function?

I though it *does* work when you use Convert.ToInt32 (or CInt) ?

One the the things about VB.NET is that it likes to be type-safe,
especially if you (as you always should) have Option Strict On. One of
the type safety features is that when you are doing something which
could result in the loss of information, you must be explicit about it.

So you can say

Dim ss As Short = 32
Dim ii As Integer = ss


with no problem, because all Short values can be held in an Integer. But
were you to try

Dim ii As Integer = 32
Dim ss As Short = ii

you would get a warning, because Integer to Short is a *narrowing*
conversion - there are some Integer values which can't be held in a
Short, so such an assignment is *unsafe*. Even though it is obvious to
us that 32 will fit in a Short, the compiler pretty much only works one
line at a time, and all it sees is that you are trying to fit a
(potential) quart in a pint pot.

It's exactly the same in your problem. Sure, session("ApplicantID")
might only ever *be* a small number, but the *variable* is an Int64, so
the compiler will not *automatically* convert it to an Int32, which is
what would have to happen for the calling signature to match the
definition signature. Thus the error message.
 
T

tshad

Larry Lard said:
In this group we would prefer to say (Integer, String, Integer, Integer),
but we know what you mean.

Sorry, my C is showing through.
Well, if it's a constant that the compiler thinks looks like an Integer,
yes.


It works, I presume.

Yes it does.
What would you like to happen if session("ApplicantID") happened to be ten
billion (which doesn't fit in an Integer) ?

But that would never happen.

I'm not really sure why it is showing as Int64, but I would have thought
that it would convert the type unless, as you say, the value is out of
bounds. Obviously that is not the case, as you explain below.

Thanks,

Tom
As it turns out, the full error message does tell you exactly what the
problem is...

I though it *does* work when you use Convert.ToInt32 (or CInt) ?

Sorry, I meant "does".
 
L

Larry Lard

tshad said:
But that would never happen.

I'm not really sure why it is showing as Int64, but I would have thought
that it would convert the type unless, as you say, the value is out of
bounds. Obviously that is not the case, as you explain below.

The compiler has to be strict; it can't know that the applicant ID
values 'will always' be convertible, unless we help it by providing the
explicit conversion - by doing so we are saying "Don't worry dear
compiler, I take full responsibility for the runtime problems that might
occur by trying to convert a too-large Int64 into an Int32. Please carry
on compiling."

As to why it's an Int64 to start with - I don't actually know enough
ASP.NET to be able to suggest an explanation.
 

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