Array of pointers
in [Visual Basic]
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From: xytsrm on 10 Oct 2009 13:01 Problem" Lets say that I have several variables defined: Dim A As String Dim B As String Dim C As String In the program I want to retain the references A,B and C, but I would like to assign values to A, B and C by indexing. In other words what I would like to create is an array of pointers [ie. Dim X(3)] to A, B, and C, such that by equating X(1) = "message 1", then A = "message 1". VarPtr can be used to make X(1) reference A by X(1) = VarPtr(A), but I'm not sure how to indirectly assign "message1" to A via X(1). Perhaps there's an easier way? Can anyone help? X.
From: dpb on 10 Oct 2009 13:48 xytsrm wrote: > Problem" > Lets say that I have several variables defined: > > Dim A As String > Dim B As String > Dim C As String > > In the program I want to retain the references A,B and C, but I would like > to assign values to A, B and C by indexing. In other words what I would like > to create is an array of pointers [ie. Dim X(3)] to A, B, and C, such that by > equating X(1) = "message 1", then A = "message 1". VarPtr can be used to > make X(1) reference A by X(1) = VarPtr(A), but I'm not sure how to indirectly > assign "message1" to A via X(1). Perhaps there's an easier way? Can anyone > help? Afaik in VB your only option would be to use tricks such as the CopyMemory API or an external language routine that allows such equivalencing; VB does not have such a facility in the language. --
From: Ralph on 10 Oct 2009 13:43 "xytsrm" <xytsrm(a)discussions.microsoft.com> wrote in message news:527FC413-4CF6-4AC2-B7C9-F8BF7EA6D3F2(a)microsoft.com... > Problem" > Lets say that I have several variables defined: > > Dim A As String > Dim B As String > Dim C As String > > In the program I want to retain the references A,B and C, but I would like > to assign values to A, B and C by indexing. In other words what I would like > to create is an array of pointers [ie. Dim X(3)] to A, B, and C, such that by > equating X(1) = "message 1", then A = "message 1". VarPtr can be used to > make X(1) reference A by X(1) = VarPtr(A), but I'm not sure how to indirectly > assign "message1" to A via X(1). Perhaps there's an easier way? Can anyone > help? > Yeah there is an easier way - don't go there. VarPtr (along with StrPtr and ObjPtr) are undocumented functions to make it easier to work with API calls that require addresses. ObjPtr does have some use in identifying and tracking a specific Object within a VB application, for the others knowing the address of something in VB is generally useless. -ralph
From: xytsrm on 10 Oct 2009 14:32 Thanks dpb, I thought I had done this in VB along time ago, but it might have been another language. The VarPtr does allow me to get the reference to the variables; perhaps there's another undocumented function that would make the indirect assignment. X. "dpb" wrote: > xytsrm wrote: > > Problem" > > Lets say that I have several variables defined: > > > > Dim A As String > > Dim B As String > > Dim C As String > > > > In the program I want to retain the references A,B and C, but I would like > > to assign values to A, B and C by indexing. In other words what I would like > > to create is an array of pointers [ie. Dim X(3)] to A, B, and C, such that by > > equating X(1) = "message 1", then A = "message 1". VarPtr can be used to > > make X(1) reference A by X(1) = VarPtr(A), but I'm not sure how to indirectly > > assign "message1" to A via X(1). Perhaps there's an easier way? Can anyone > > help? > > Afaik in VB your only option would be to use tricks such as the > CopyMemory API or an external language routine that allows such > equivalencing; VB does not have such a facility in the language. > > -- > > >
From: Henning on 10 Oct 2009 14:59
Poke? No, soory just in the mode for it from discussions with some Scott ;) /Henning "xytsrm" <xytsrm(a)discussions.microsoft.com> skrev i meddelandet news:44DEDE47-6104-448F-BCFD-C5FEAF8E897D(a)microsoft.com... > Thanks dpb, > > I thought I had done this in VB along time ago, but it might have been > another language. The VarPtr does allow me to get the reference to the > variables; perhaps there's another undocumented function that would make > the > indirect assignment. > > X. > > > "dpb" wrote: > >> xytsrm wrote: >> > Problem" >> > Lets say that I have several variables defined: >> > >> > Dim A As String >> > Dim B As String >> > Dim C As String >> > >> > In the program I want to retain the references A,B and C, but I would >> > like >> > to assign values to A, B and C by indexing. In other words what I >> > would like >> > to create is an array of pointers [ie. Dim X(3)] to A, B, and C, such >> > that by >> > equating X(1) = "message 1", then A = "message 1". VarPtr can be used >> > to >> > make X(1) reference A by X(1) = VarPtr(A), but I'm not sure how to >> > indirectly >> > assign "message1" to A via X(1). Perhaps there's an easier way? Can >> > anyone >> > help? >> >> Afaik in VB your only option would be to use tricks such as the >> CopyMemory API or an external language routine that allows such >> equivalencing; VB does not have such a facility in the language. >> >> -- >> >> >> |