Function Overloading Add Result Type To Parameter Signature?
Dec 7, 2009
Can someone on the VB language team explain why a function result type is not part of the parameter signature?If it were then function overloads would also work for functions that only differ by the result type. In some cases, this is useful (aka cleaner code) especially when you have strongly typed data.
Other languages have this and implement it by considering the function result as an OUT parameter either as param 0 or at the end of the param list (stack) so existing type matching verification can be performed by the compiler.
In VB, the workaround is just messy and would be easily fixed by a language change. This example is overly simplified and not meant as a solid justification for the request Say you have a parse requiirement that takes a comma delimited string in the form: "31,32,33,34" or "bob,carol,ted,alice"
In you code,
[Code]...
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May 20, 2011
I need type parameter overloading as such:[code..]
so that i can New Map(Of Human) and the compiler will automatically match it to Public Class Map(Of TKey, TValue) and if i new Map(Of String) the compiler will automatically match it to Public Class Map(Of TKey As IEquatable(Of TKey), TValue) (since String is an IEquatable(Of String))
Right now my solution is to give the class different names as such:[code...]
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Mar 9, 2011
I want to have a "template" function that can receive different parameter and a type parameter, like:[code]But Vb told me that tupeList is not defined... is there a way I can do that?
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Mar 10, 2011
Is it possible in VB to have a function that can receive diffrent parameter, like a String or a Integer or a custom class type?
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Jun 11, 2012
I need to create a function which have either 1 parameter with a string as data type or 2 parameters with double as data type.Something like the substring method.
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Aug 1, 2011
After reading this post i realized that i cannot pass an anonymous type as a parameter to a function. So what other options do i have?
Perhaps, passing a Query.ToList as parameter would help, or am i re-inventing the wheel?
Update: I have the following query, which i would like to pass to a function:
Sub Test
Dim Query = (From c In DB Select New With { .ElementName = c.Name })
DoSomething(Query)
[Code].....
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May 5, 2009
I'm compiling a VB.Net 2.0 app (created in VS2008) using msbuild, and now I've added a generic return type, it's giving me the following:
Warning: Type library exporter encountered a generic type instance in a signature. Generic code may not be exported to COM.
Having just spent ages removing all of the previous warnings, I don't really want to add a new one. Any idea how to get rid of it (aside from not using generics)?I don't know what details I'd put in the attribute, or what number to put in the project-level ignore list.
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Sep 8, 2009
I am trying to define a function that I would like to specify a datatype as in input of the function. The only/best way I evision doing this is by making a enum with the range of datatypes the function will accept and us the enum as part of the function's signature.
example
Enum MyDataTypesString
Int32
DbNull
[Code]....
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Mar 22, 2012
I want to pass an optional parameter to a function of type System.Drawing.Color. The problem I am having is that when I declare the function it says "Constant expression is required" but I have tried variations of the following, including integers, full qualified indentifiers, even old vbWhite constants to no avail.
[Code]...
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Oct 26, 2011
The compiler is telling me that these signatures are incompatiable, but they seem fine to me.[code].....
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Apr 5, 2012
I have a section of code that deletes a lot of columns, one at at time, based on conditions that arise. Currently it does this:
objrpt.objXLSheet.Columns(col) _
.EntireColumn.Delete(Excel.XlDeleteShiftDirection.xlShiftToLeft)
There are so many of these, that I'm getting tired of looking at these lines so I want to curry the references to the Excel stuff.I tried:
Dim DelCol As Func(Of Integer) = Function(col As Integer) _
objrpt.objXLSheet.Columns(col) _
.EntireColumn.Delete(Excel.XlDeleteShiftDirection.xlShiftToLeft)
but that won't compile, giving me the error: "Nested function does not have the same signature as delegate 'System.Func(Of Integer)'. Ah forget it. I see that I'm trying to call a method from a function. I guess that won't work.Wait, I'm now trying it another way. I first defined a function:
Private Function DeleteColumn(ByRef objrpt As ExcelReport, ByVal col As Integer) As Object
DeleteColumn = Nothing
Dim objrng As Excel.Range
[code]....
Now the error message is a little different:
"Nested function does not have the same signature as delegate 'System.Func(Of Object)'.
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May 15, 2011
I'm planning on using the Smart Device Framework 2.3 to use the signature control panel in a Windows Mobile 5 application using the compact framework 3.5.
The control has the option to save the signature as either a byte array of points, or as a bitmap. Now seeing as I want to store the signature in a sql compact database, I guess the byte array is going to be better. The trouble is, I'm not sure how to render that in a full WinForms application after I've transferred it back to the desktop.
I need to show the signature on a report, so it would need to be an image I could link/embed into the report.
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Oct 22, 2009
I want to use explicit conversion (CType function in VB.NET) to convert the variable d from double type to integer type and store the result as 132.
Imports System.Console
Module Module1
Sub Main()
[CODE]...
This is my code. But Visual Basic tells me an error: Error1Type 'i' is not defined.C:\Users\mihaispr\Desktop\Conversie explicita\Conversie explicita\Module1.vb1922Conversie explicita
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Feb 17, 2011
I'm currently working with a client's VB.Net code, which was developed for them by a small development shop a few years ago and which they purchased and have been maintaining and uprgrading since. This client's primary developer is out on indefinite (likely permanent) medical leave and I'm now filling in until they bring in a full timer (as I'm a contractor here). My current task is to add some functionality to a the VB.Net code they purchased. I'm finding practices and techniques in the code that absolutely baffle me and can't make the code do what I want. I'm starting to wonder if it's me and was hoping to get some thoughts on the code I've encountered.
For example: Setting a variable to accept the result of a function by calling the function with many parameters, clearing the parameters in the function, setting them to some value, calling another function with those new values, then never using the values returned by the functions. I'll add a code snippet in the first comment since this is already getting long.
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Oct 24, 2011
I have an rdlc report with a TextBox that contains
=Parameters!ReportParameter1.Value
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Jun 7, 2011
I have a storedproc accepts parameters in XMLtype as
CREATE OR REPLACE PROCEDURE GetDetails(
p_para IN XMLTYPE,
[code].....
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Dec 13, 2011
I need to execute a stored function in oracle or sql through vb.net. I created a command object. Depending on the database type(oracle or SQL) i am preparing the Command text as Select functionName(?,?,?,?,?,?,?,?) from dual; (For Oracle) Adding the parameter values of the function. Now performing the ExecuteScalar which is not working saying invalid parameter. This works with ODBC connection string. But ODBC doesn't with 64bit. My Requirement: Code should execute a user defined stored procedure by taking the values at runtime.
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Nov 19, 2010
i am getting all filenames from a directory.parsing out the directory names & the .vb extension then converting those filesnames to classes.Every file in the LPCriteria direcotry is its own class with a "Evaluate" function.[code]
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Jan 9, 2012
My IDE is MS Visual Studio 2008.I just want to ask how can I get the result of a store procedure from MS Access using VB.Net and use the result in a Crystal Report.
I have a Windows Application Project that requires this function.
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May 28, 2012
I want to make a GetAllContacts method which takes a sort parameter of type Func(Of Contact, TKey) which is the same type that the OrderBy method for an IEnumerable(Of Contact) takes.[code]"Too many arguments to extension method 'Public Function ElementAtOrDefault(index As Integer) As Contact' defined in 'System.Linq.Enumerable'." on the second parameter.
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Apr 16, 2009
how can i capture a signature from an Electronic Signature Pad and store it in database. is there any particular api or it can be captured just like capturing an image from a WebCam. Is it manufacturer specific?
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Jul 11, 2010
I was trying to use a GetAsyncKeyState code but each time I run the program an error occers where
[Code]....
'A call to PInvoke function 'WindowsApplication1!WindowsApplication1.Form1::GetAsyncKeyState' has unbalanced the stack. This is likely because the managed PInvoke signature does not match the unmanaged target signature. Check that the calling convention and parameters of the PInvoke signature match the target unmanaged signature.' The full code is in timer with (1) time interval
[Code]...
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Jan 18, 2012
I am having trouble with using sumifs excel function in vb.net. I can use sum function with "cells" but I could not get result from sumifs function with "columns".
It is giving "OleAut reported a type mismatch." error.
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Dim oExcel As Object
[Code].....
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Sep 22, 2011
I have a problem with Asc() function as a blow picture,I will explain each step as I do.First I convert some values to ASCII code and store in value variable, then retrieve 3rd position of variable (4th line of the picture.)
and use Asc() function to find result which it show 63. (like 5th and 6th line).But I try to manually use Chr() function, the result become 2nd and 3rd line.So for the Asc("ˆ") func. result should be 63 or 136?
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Dec 1, 2009
I would expect the following vb.net function to return a value of Nothing, but instead its returning a value of 0.
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Jul 11, 2011
I am using the following code in my project. I want to find the number of days by given the last date and now.[code] for example, when BorrowDate is "01/Jul/2011" then the result is 7 days which it should be 10 to now.
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Oct 7, 2011
When I was coding a program, I was able to find the result of a function in the Immediate Window by using:
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Jun 16, 2011
I have something that I want to do and what looks very simple, but I cannot get it to work. I want to build a function that gets as input a xdocument and some other strings. It should have a return that contains a filtered part of the xdocument in a way that I can use it as input for a new Linq function. This is what I mean:
Private Function fncGetFilteredDecendantsOfNode(ByVal xdocDoc As XDocument, _
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Oct 19, 2010
What does this error mean in VB6? Function or interface marked as restricted, or the function uses an Automation type not supported in Visual Basic.
I keep getting it when i call a particular method of a dll that comes with windows xp and beyond (in system32 called upnp.dll)
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Mar 12, 2012
I am having some issue here, and I am not too sure how to handle it. If you could lead me in the right direction
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