PInvoke GlobalGetAtomName

[PLS]

I'm having problem calling the Win32 function GlobalGetAtomName from C#.
I'm getting a debugger popup telling me that the called function has
unbalanced the stack.

I'm hoping someone here can see what I'm doing wrong.

Here is the function declaration, in a class call DDEFunctions:

[DllImport("kernel32.dll", SetLastError=true,
CharSet=CharSet.Unicode,
CallingConvention = CallingConvention.StdCall,
EntryPoint = "GlobalGetAtomNameW")]
public static extern int GlobalGetAtomName(ushort nAtom,
out String lpBuffer, int nSize);

And here is the code that calls it

public static String GetAtomString(ushort Atom)
{
if (Atom == 0)
return null;

int BufferLen;
String Buffer;

BufferLen = 514;
Buffer = new String('\0', BufferLen);

BufferLen = DDEFunctions.GlobalGetAtomName
( Atom, out Buffer, BufferLen);

if (BufferLen == 0)
{
System.Diagnostics.Trace.WriteLine("GetAtomString failed
with DLL error number " + Marshal.GetLastWin32Error().ToString());
return null;
}
else
{
Buffer = Buffer.Substring(1, BufferLen);
return Buffer;
}
}
Does anyone see the problem?

Thanks very much,
++PLS

[PLS]

It was out, but changing it to ref did not change anything.

The definition is now
[DllImport("kernel32.dll", SetLastError=true,
CharSet=CharSet.Unicode,
CallingConvention = CallingConvention.StdCall,
EntryPoint = "GlobalGetAtomNameW")]
public static extern int GlobalGetAtomName(ushort nAtom,
ref StringBuilder lpBuffer, long nSize);
In article <EE**********************************@microsoft.co m>,
mv*@spam.guard.caspershouse.com says...

What is the declaration of the function with the StringBuilder? It
shouldn't be "out", as the P/Invoke layer will know that the buffer has to
be marshaled in and out when the StringBuilder is in place.

[Peter Duniho]

On 2007-11-03 19:34:28 -0700, PLS <no****@nowhere.comsaid:

It was out, but changing it to ref did not change anything.

I think he means to make the parameter not "out" _or_ "ref". Just make
it a regular by-value parameter. P/invoke will handle the rest.

Pete

[Willy Denoyette [MVP]]

"PLS" <no****@nowhere.comwrote in message
news:MP************************@msnews.microsoft.c om...

It was out, but changing it to ref did not change anything.

The definition is now
[DllImport("kernel32.dll", SetLastError=true,
CharSet=CharSet.Unicode,
CallingConvention = CallingConvention.StdCall,
EntryPoint = "GlobalGetAtomNameW")]
public static extern int GlobalGetAtomName(ushort nAtom,
ref StringBuilder lpBuffer, long nSize);
In article <EE**********************************@microsoft.co m>,
mv*@spam.guard.caspershouse.com says...

> What is the declaration of the function with the StringBuilder? It
shouldn't be "out", as the P/Invoke layer will know that the buffer has
to
be marshaled in and out when the StringBuilder is in place.

Why did you change the nSize into a long? it should be an int.
lpBuffer should be a "StringBuilder" not a "ref StringBuilder".
Willy.

[PLS]

In article <uU**************@TK2MSFTNGP03.phx.gbl>,
wi*************@telenet.be says...

"PLS" <no****@nowhere.comwrote in message
news:MP************************@msnews.microsoft.c om...

It was out, but changing it to ref did not change anything.

The definition is now
[DllImport("kernel32.dll", SetLastError=true,
CharSet=CharSet.Unicode,
CallingConvention = CallingConvention.StdCall,
EntryPoint = "GlobalGetAtomNameW")]
public static extern int GlobalGetAtomName(ushort nAtom,
ref StringBuilder lpBuffer, long nSize);
In article <EE**********************************@microsoft.co m>,
mv*@spam.guard.caspershouse.com says...

What is the declaration of the function with the StringBuilder? It
shouldn't be "out", as the P/Invoke layer will know that the buffer has
to
be marshaled in and out when the StringBuilder is in place.

Why did you change the nSize into a long? it should be an int.
lpBuffer should be a "StringBuilder" not a "ref StringBuilder".
Willy.

I was trying various things to get something to work. I ended up with
StringBuilder and int.

I've also corrected this function signature on pinvoke.net