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...]
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]...
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?
View 2 RepliesI have a storedproc accepts parameters in XMLtype as
CREATE OR REPLACE PROCEDURE GetDetails(
p_para IN XMLTYPE,
[code].....
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]
View 1 RepliesI 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.
View 2 RepliesFor each column in data table i want to add parameter with same data type as column data type. But looks it's not that simple.
Dim cmd As New SqlCommand
Dim dType As New System.Data.SqlDbType
For Each cl As DataColumn In DataTable1.Columns
[CODE]...
How can I do this?
This is kind of two questions (one more specific than the other).If I have a method like this:[code]Can I qualify Foo against another type (for instance can I require that Foo be a String that also implements IInterface?).I'm imagining something vaguely similar to this:[code]Additionally, is there any way to qualify the Type parameter?For instance, can I require that the Type I take as a parameter is of a particular class tree?I should mention that I am using this in the context of a property of an attribute so the class declaration itself cannot be generic (this is purely focused on qualifying a method parameter rather than typing a class and its methods).
View 3 RepliesI did create a XDateTime class that is able to handle inaccurate date and time. This class has all the CType operators required to convert to and from a string and it has been fully tested during the last months.
[Code]...
I've searched for an answer and found some c#-examples, but could not get this running in vb.net:
I thought of something like the following[code]...
I know, I can create a new instance with the Activator.Create... methods, but how to create an array of this type or just declare a new variable?
I'm trying to create a function to parse out all values in a multidimensional Array with all but one dimension given. The details are not relevant, but for this function I need to return an one-dimensional Array containing values of the same type the original multidimensional Array has.To pass any Array with any dimension to my function, I declared the type of this parameter as Array. However, how would I create a new Array of that specific type (e.g. Integer)?Currently I have the following code:
Function GetRow(ByVal arr As Array) As Array
Dim result As (...) 'This should be Integer() if arr contains Integers, etc.
Return result
[code].....
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?
View 4 RepliesIs it possible to have an optional parameter of the type list?Ex.
Private Function TestFunction(Optional ByRef MyList As List(Of Double))
The real problem is giving the list a default value. When dimming a new list, you can use the code below to give it a starting value:
Dim MyList As New List(Of Double)(New Double() {1, 2, 3, 4, 5})
But even after trying many variations of the above code, I cannot get it to work as an optional parameter.
I'm trying to use the type Boolean for some parameter.
<AttributeUsage(AttributeTargets.Method, Inherited:=True, AllowMultiple:=False)>
Public Class MyAttribute
Inherits Attribute
[code].....
im making a function that disables controls except for a type of control i want to specify. how would I make the header of this procedure is my procedure should capture a control and a object of any type If I would call modUtilities.DisableControls(Panel_OwnerInfo, CheckBox_HasCell) is should disable all the controls inside Panel_OwnerInfo except for the CheckBox_HasCell Now I've done the disabling thing, but how would I specify the procedure parameter to recieve a class type?
[Code]...
I have a base class with a static function that returns a typed dataset. I have several classes that inherit the base class with a non-static function that returns the same typed dataset. On these methods I get the 'Return type of parameter yadda
is not CLS-compliant' I don't understand where this is coming from. I have non unsigned integers/etc. in this dataset.
I want to include an optional parameter in a function statement that is of the type Unit. For example:
Public Shared Function NewTable(Optional ByVal TableWidth As Unit) As Table
Optional parameters require a default value, but I cannot figure out how to set a default value for a Unit type.
I'd like to auto-register the common/simple services in my unity container. I think the cleanest way to do this would be via a custom atribute.I can then examine all the (abstract) classes in an assembly and register those types with unity.The piece of information I'm missing is the interface(s) that the class wants to be registered against
eg:
Public Class AutoRegisterAttribute
Public Property ForInterface As System.Type
Public Sub New(ForInterface As System.Type)
[code]....
Note, I don't just want to find any class it implements as shown with IDisposableI've tried doing this using generics (generics can't inherit from Attribute), with a Type Parameter (Passing in IEngine.GetType results in a "Constant expression is required")
I have the following VB.NET function, for example:
Public Function MyFunction (Of TData) (ByVal InParam As Integer) As TData
End Sub
How do I, in a function, determine if TData is a NULLable Type?
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].....
I have a TreeView, which contains nodes. When a user clicks on a node, corresponding CrystalReport document should be created and displayed.For example, names of my nodes are: "PeriodReport1", "PeriodReport2", "PeriodReport3". My CrystalReport documents are named same: "PeriodReport1", "PeriodReport2", "PeriodReport3".How can I create and display right type of crystal reports document? I could do something like this:
select case reportName
case "PeriodReport1"
[code].....
I have a datagridview with a checkbox column. I'm trying to update data in the dataset but I keep getting this error: Conversion from string "ExtendDate" to type 'Integer' is not valid.The parameter type for ExtendDate is boolean but i'm not sure if that's the correct type.
Code:
Dim Col11 As New DataGridViewCheckBoxColumn
With Col11
.DataPropertyName = "ExtendDate"
.HeaderText = "Extend Date"
[code]....
Is it possible to replace these two functions
Function f1 (s As String) As class1()
Dim a() As String = Split(s)
Dim b(UBound(a)) As class1
[code].....
how to implement Nullable Parameter of type string in vb.net
Function:
sub savedetail(byval name as string, byval age as integer)
if name isnot nothing then
some work
end if
[code]....
I'm trying to create a function that searches up a WebControl's parent-child relationship (basically the opposite of WebControl.FindControl(id as String), but looking for a specific WebControl type).
Example
I have a user control in an ItemTemplate for a GridViewRow. I'm trying to reference the GridViewRow from the user control. The user control may or may not be inside a div or other types of controls, so I don't know exactly how many parent's up to look (i.e. I can't just use userControl.Parent.Parent). I need a function that will find the first GridViewRow that it finds on the way up the parent-child hierarchy.
What happened when parameter passing. Here is a test project I write.
Public Class Form1
'1.test string
Private Sub btnString_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnString.Click
Dim str1 As String = "x"
[Code] .....
From the project you can see, when pass integer type parameter (value type) into a method , if use ByVal keyword, the value won't change. If use ByRef keyword, the value will change (I can understand it, to my understanding, when using ByVal, It pass the value of the argument to the method; when using BvRef, it pass the address of the argument to the method, so the value can be rewrite)
Well, for the following two scenarios , I can't understand why.
String type is reference type, but it acts like integer type.
Val type is also reference type, but no matter what you use(ByVal or ByRef), the result will be the same.
So my question is what actually passed into method? What's the underlying mechanism about pass parameter? What's the effect of ByRef and ByVal to value type and reference type?
Here is some code I use for creating a table and the data adpater for it...
vb
Dim cmdString As String = String.Format("CREATE TABLE {0} (" & _
"EventID INT IDENTITY(1,1) NOT NULL, " & _
[code]....
In both C# and VB, type parameter modifiers are used to express the variance of type parameters. For example, the C# version looks like:
[Code]....
Since variance specifications basically restrict where and how a type parameter can be used, I tend to think of them as additional constraints on type parameters. I'm just curious as to why they aren't represented so. I mean, why are they represented in both languages as additional modifiers on type parameters, instead of being added to the type constraint list? If they were type constraints, the C# version would've looked like:
[Code]....
I have searched for two weeks, every night, exhaustively reading forum threads and trying all suggested solutions no matter how outlandish. Just as is the case with the many many forum threads about this same issue, the site works fine on my development machine. It deploys with no errors. It works from the production server and reads data from the database, but when it attempts to access a profile it crashes with this error.
A number of posts say to check or uncheck an option called "remove app_code.compiled file" but apparently this was a Visual Studio 2005 option. It is nowhere to be found in Visual Studio 2010. A number of posts say to make sure the App_Code.dll is present in my bin directory. It is present. I've deleted the app_code.compile file manually to see if that made any difference. I've changed the target framework from 4.0 to 2.0 and 3.5. I've completely deleted the site in IIS, created a different folder with a different name and redeployed the site with every combination of "allow this precompiled site to be updatable" and "Use fixed naming and single page assemblies".
i've included references to System.Web.Profile and System.Web and System.Web.Profile.ProfileCommon. I've created a new, fresh website targeting .net framework v4.0 and copied that web.config file to my application and recreated my profile entries to ensure that I didn't jack anything up in the config file along the way.
say I have two POCOs I'm using in EF code first
Public class C1
property F1 as integer
End Class
Public class C2
property F2 as String
End Class
I want to have a function that will create a list either of C1 or C2, to be used in some generic operation, such that
[Code]...