byref

问题 I'm a C# developer working on a VB.NET project, and VS keeps trying to get me to use the := thingie when I call a function with a ByRef parameter like so: While reader.Read() HydrateBookFromReader(reader:=???) the HydrateBookFromReader function has the following signature: Public Function HydrateBookFromReader(ByRef reader As SqlDataReader) As Book Why does intellisense keep insisting that I use that := construction, and what is it for? 回答1: In VB, the := is used in specifying named

问题 If arrays are returned by reference, why doesn't the following work: 'Class1 class module Private v() As Double Public Property Get Vec() As Double() Vec = v() End Property Private Sub Class_Initialize() ReDim v(0 To 3) End Sub ' end class module Sub Test1() Dim c As Class1 Set c = New Class1 Debug.Print c.Vec()(1) ' prints 0 as expected c.Vec()(1) = 5.6 Debug.Print c.Vec()(1) ' still prints 0 End Sub 回答1: In VBA, arrays are never returned by reference unless they are returned through a ByRef

问题 Title says it all... Please read this full compiling sample code : Imports System.Runtime.CompilerServices Imports System.ComponentModel Imports System.Drawing Public Class PropertyChangedNotifier Implements INotifyPropertyChanged Protected Sub SetProperty(Of T)(ByRef _backingStoreField As T, ByVal new_value As T, <CallerMemberName> Optional ByVal propertyname As String = "") ' PropertyChangedNotifier allow me to add functionality here like ' PropertyChanging with old and new value ' Locked

问题 I think I have a fairly good idea what the difference is between ByVal and ByRef in VB, but my issue is when I try using it in conjunction with a member that is declared with WithEvents . I have the following method: Private Sub SafeCloseAndDeRefConnection(ByRef cnx As ADODB.Connection) On Error GoTo ErrH If Not cnx Is Nothing Then If (cnx.State And adStateConnecting) = adStateConnecting Then cnx.Cancel End If If (cnx.State And adStateOpen) = adStateOpen Then cnx.Close End If Set cnx =

问题 My problem is: Main form has 9 command buttons and continuous subform. Click on some button open other form with text box for entering quantity and two command buttons. When click on the first button I want to use caption of pressed button from main form for query. How to get that button caption? Thanks. 回答1: You have just clicked the button, you know the name of the control, so I do not quite see the problem, other than that it all sounds like quite a bad idea. Private Sub cmdClickMe_Click()

问题 I have this code: let sumfunc(n: int byref) = let mutable s = 0 while n >= 1 do s <- n + (n-1) n <- n-1 printfn "%i" s sumfunc 6 I get the error: (8,10): error FS0001: This expression was expected to have type 'byref<int>' but here has type 'int' So from that I can tell what the problem is but I just dont know how to solve it. I guess I need to specify the number 6 to be a byref<int> somehow. I just dont know how. My main goal here is to make n or the function argument mutable so I can change

问题 Initially in my main code section I had an ugly if statement - though ugly it would run. I decided to make it a function that I would call, this caused me to get an error " Compile error: ByRef argument type mismatch ". My assumption is that the function needs to be referenced properly, though I've been reading the documentation and can't see why >.< Declaring ShiftValue variable: Dim ShiftValue As String ShiftValue = LCase(Sheets("Raw_Rota").Cells(Counter, "C").Value) The function contents

问题 This question is sort of built from my last question mainly because I want to avoid using Global variables because of its limitations. See answer to link here: How do I call upon an array created by a different function? I'm attempting to use an array created from a user-defined function in another user-defined function. I want to avoid setting the array as Global because the second function won't automatically recalculate. For this exercise, I have two separate functions. The first function

问题 I have question related passing parameters byRef, I have VB.NET based class library in which some functions are defined with byref argument types. These parameters are parent class objects and when I tried to call this function and pass child class object in byref argument it works in VB.NET but I am unable to do same thing in C# following is test code i am trying Public Class Father Private _Cast As String Public Property Cast() As String Get Return _Cast End Get Set(ByVal value As String)

问题 Why does this: Private [Function] As Func(Of Double, String) = Function(ByRef z As Double) z.ToString gives the following error: Nested function does not have a signature that is compatible with delegate String)'. While this: Private [Function] As Func(Of Double, String) = Function(ByVal z As Double) z.ToString Does not? (The difference is ByRef/ByVal) Furthermore, how might I implement such a thing? 回答1: You are getting this error because the delegate type Function (ByVal z As Double) As