PInvoke and constants

  • Thread starter Thread starter vertigo
  • Start date Start date
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vertigo

Hello
I use some win 32 API function for example:
HANDLE CreateFile(
LPCTSTR lpFileName,
DWORD dwDesiredAccess,
DWORD dwShareMode,
LPSECURITY_ATTRIBUTES lpSecurityAttributes,
DWORD dwCreationDisposition,
DWORD dwFlagsAndAttributes,
HANDLE hTemplateFile
);

my code:
[DllImport("kernel32.dll")]
static extern IntPtr CreateFile(string name, int DesiredAccess, int
ShareMode, IntPtr securityAttributes, int CreationDisposition,
int FlagsAndAttributes, IntPtr TemplateFile);
later:
Handle = CreateFile( Name, GENERIC_WRITE, FILE_SHARE_READ, IntPtr.Zero,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, IntPtr.Zero );

But i compiler does not know these constants: GENERIC_WRITE,
FILE_SHARE_READ, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL.
How can i access them ?

Thanx
Michal
 
You have to "handcode" them yourself with the values from the SDK header
files (winnt.h), something like this will do:

const uint GENERIC_READ = 0x80000000;
.....

Willy.
 
This may help you:

http://www.pinvoke.net/

ShaneB

Willy Denoyette said:
You have to "handcode" them yourself with the values from the SDK header
files (winnt.h), something like this will do:

const uint GENERIC_READ = 0x80000000;
....

Willy.

vertigo said:
Hello
I use some win 32 API function for example:
HANDLE CreateFile(
LPCTSTR lpFileName,
DWORD dwDesiredAccess,
DWORD dwShareMode,
LPSECURITY_ATTRIBUTES lpSecurityAttributes,
DWORD dwCreationDisposition,
DWORD dwFlagsAndAttributes,
HANDLE hTemplateFile
);

my code:
[DllImport("kernel32.dll")]
static extern IntPtr CreateFile(string name, int DesiredAccess, int
ShareMode, IntPtr securityAttributes, int CreationDisposition,
int FlagsAndAttributes, IntPtr TemplateFile);
later:
Handle = CreateFile( Name, GENERIC_WRITE, FILE_SHARE_READ, IntPtr.Zero,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, IntPtr.Zero );

But i compiler does not know these constants: GENERIC_WRITE,
FILE_SHARE_READ, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL.
How can i access them ?

Thanx
Michal
Click to expand...
Click to expand...
 
No, not you :) That was for the original poster.

Anyhoo, I too avoid PInvoke as much as I can...but there are still many
things missing from the framework. Hopefully 2.0 will address many of them.

ShaneB
 
Sure, there are things missing, but as far as I can see, a lot of what's
fount at http://www.pinvoke.net/ is covered by the FCL.
The problem is that people used to VB's 'declare ...' stuff and C/C++ /Win32
programming, are simply looking for direct replacements of Win32 API's when
porting applications to .NET, this without taking some time to learn/see
what's covered by the FCL.
Don't get me wrong, there's nothing basically wrong with PInvoke:
- as long as you know there are no managed alternatives and,
- you know perfectly well what the API is doing, just go for it.
But, a lot of "developers" are blindly using the PInvoke signatures and data
definitions without looking at the API requirements, platform dependencies,
security implications and maintenance issues related to OS versions updates
after deployment, sooner or later they will be faced with a lot of (hard to
trace) issues.
There's a group of PInvoke API's I would call "dangerous" when used in a
managed application because they can disturb the correct functioning of the
CLR.

Willy.
 
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