C# supports pointer.

[Guest]

What do we do for pointer in VB.NET?

Thanks

 

[Herfried K. Wagner [MVP]]

What do we do for pointer in VB.NET?

C# supports pointers only inside 'unsafe' blocks which are only useful in
some very rare cases. VB.NET gladly doesn't support them. What do you want
to archieve?

 

[Crouchie1998]

Dim ptr As IntPtr

Crouchie1998
BA (HONS) MCP MCSE

 

[Armin Zingler]

Dim ptr As IntPtr

hehe. )

Armin

 

[Mike Labosh]

Dim ptr As IntPtr

hehe. )

You guys are *evil*. Let me see some VB.NET code that dereferences ptr and
I'll be impressed.

--
Peace & happy computing,

Mike Labosh, MCSD

"Mr. McKittrick, after very careful consideration, I have
come to the conclusion that this new system SUCKS."
-- General Barringer, "War Games"

 

[Armin Zingler]

You guys are *evil*. Let me see some VB.NET code that dereferences
ptr and I'll be impressed.

dim b(499) as byte
Marshal.Copy(ptr, b, 0, 500)

msgbox b(17) 'reference to b(17)

;-)


Armin

 

[Dragon]

Hello Rulin,

If you have an variable and you want its address:
~
Dim GCH as GCHandle = GCHandle.Alloc(YourVar, GCHandleType.Pinned)
REM now GCH.AddrOfPinnedObject is pointer to your var so do whatever you
want
GCH.Free()
~

On the other hand, if you have an address, you can get a value:
~
DesiredValue = CType(Marshal.PtrToStructure(YourPointer,
DesiredValue.GetType), TypeOfDesiredValue)
~
Note that this time you actually get COPY of the value.

Marshal and GCHandle are located in System.Runtime.InteropServices
namespace.

Hope this helps

Dragon

"Rulin Hong" <[email protected]> ÓÏÏÂÝÉÌ/ÓÏÏÂÝÉÌÁ ×
ÎÏ×ÏÓÔÑÈ ÓÌÅÄÕÀÝÅÅ:
news:[email protected]...

 

[Jay B. Harlow [MVP - Outlook]]

Mike,
As Armin suggests, there are a number of methods on
System.Runtime.InteropServices.Marshal class that allows you to dereference
an IntPtr.

Marshal.Read* & Marshal.Write* may be "better" to use then Marshal.Copy. I
find Marshal.PtrToStructure & Marshal.StructureToPtr to be extremely useful
in some interop cases.

Of course Marshal.PtrToString* & Marshal.StringTo* are invaluable when
dealing with strings.

I've even used Marshal.GetObjectForIUnknown once or twice...

Hope this helps
Jay

| >> Dim ptr As IntPtr
| >
| > hehe. )
|
| You guys are *evil*. Let me see some VB.NET code that dereferences ptr
and
| I'll be impressed.
|
| --
| Peace & happy computing,
|
| Mike Labosh, MCSD
|
| "Mr. McKittrick, after very careful consideration, I have
| come to the conclusion that this new system SUCKS."
| -- General Barringer, "War Games"
|
|