D - win32 Api Calling
- Lewis (18/18) Dec 12 2003 i made the following code to try to figure out how api calls are made in...
- Walter (11/11) Dec 12 2003 Try the following version:
- Lewis (4/23) Dec 12 2003 thanks walter, you've saved me from running screaming back to vb :)
- Walter (3/6) Dec 12 2003 It's a big change going from an untyped language to a typed one. Good lu...
- Lewis (18/18) Dec 14 2003 ok, somebody stop me when i get way out in left field :)
- Lewis (43/43) Dec 14 2003 WoW... it worked!! Now i only have to link to two library's and i can ca...
- Sean L. Palmer (12/55) Dec 15 2003 Not completely general since you still have to know a priori what parame...
- Lewis (4/18) Dec 15 2003 Thanks for the tips! anything like that helps alot since i have alot to ...
i made the following code to try to figure out how api calls are made in
windows from D, but no matter what i try the type checking wont allow me
to call it. the Docs sugest that you can use the .append(0) to add a
null at the end of a string, but it wouldnt let me do that either...
either way could anyone give me some tips on which direction to go with
this code...
import std.c.stdio;
extern (Windows): private void *GetComputerName(uint *lpBuffer,uint nSize);
int main( char [] [] args ) {
char[] newname = new char[254];
newname = newname ~ "\n";
if (GetComputerName((uint) *newname, (uint)255))
{
printf("%s\n",newname);
}
return 1;
}
thanks for any help
Dec 12 2003
Try the following version:
import std.c.stdio;
extern (Windows): int GetComputerNameA(char *lpBuffer,uint nSize);
int main( char [] [] args ) {
char[] newname = new char[255];
if (GetComputerNameA(newname, newname.length))
{
printf("%.*s\n",newname);
}
return 1;
}
Dec 12 2003
Walter wrote:
Try the following version:
import std.c.stdio;
extern (Windows): int GetComputerNameA(char *lpBuffer,uint nSize);
int main( char [] [] args ) {
char[] newname = new char[255];
if (GetComputerNameA(newname, newname.length))
{
printf("%.*s\n",newname);
}
return 1;
}
thanks walter, you've saved me from running screaming back to vb :)
Once i can get a feel for the syntax more, and how things work i think
ill be ok... ive programmed for years, just not in this type of language.
Dec 12 2003
"Lewis" <dethbomb hotmail.com> wrote in message news:brds73$1g41$1 digitaldaemon.com...thanks walter, you've saved me from running screaming back to vb :) Once i can get a feel for the syntax more, and how things work i think ill be ok... ive programmed for years, just not in this type of language.It's a big change going from an untyped language to a typed one. Good luck!
Dec 12 2003
extern (Windows): int GetComputerNameA(char *lpBuffer,uint nSize);
int main( char [] [] args ) {
char[] newname = new char[255];
if (GetComputerNameA(newname, newname.length))
{
printf("%.*s\n",newname);
}
return 1;
}
well unfortunatly that code gives an memory access error, but i have
managed to get it to run, but i get the following error...
Error 42: Symbol Undefined _GetComputerNameA 12
--- errorlevel 1
does that mean it couldnt find the function address in the dll?
after 12 hours of trying to get D to print my computer name out, im
certain i have a long road ahead :) however, im persistent an stubborn ;o)
Dec 13 2003
"Charles" <sanders-consulting comcast.net>
however, im persistent an stubborn ;o)
"Lewis" <dethbomb hotmail.com> wrote in message
news:breiub$7a2$2 digitaldaemon.com...
extern (Windows): int GetComputerNameA(char *lpBuffer,uint nSize);
int main( char [] [] args ) {
char[] newname = new char[255];
if (GetComputerNameA(newname, newname.length))
{
printf("%.*s\n",newname);
}
return 1;
}
well unfortunatly that code gives an memory access error, but i have
managed to get it to run, but i get the following error...
Error 42: Symbol Undefined _GetComputerNameA 12
--- errorlevel 1
does that mean it couldnt find the function address in the dll?
after 12 hours of trying to get D to print my computer name out, im
certain i have a long road ahead :) however, im persistent an stubborn ;o)
Dec 13 2003
however, im persistent an stubborn ;o)Thats what it takes! There is a very good win32 wrapper at http://hp.vector.co.jp/authors/VA028375/contents/D_windows.h.html Also you will need to link against a 'stub' library , GetComputerName is kernel.lib, link against it ( just specfiy its name on the command line, dmd foo.d kernel.lib ) Welcome to D ! C "Lewis" <dethbomb hotmail.com> wrote in message news:breiub$7a2$2 digitaldaemon.com...extern (Windows): int GetComputerNameA(char *lpBuffer,uint nSize); int main( char [] [] args ) { char[] newname = new char[255]; if (GetComputerNameA(newname, newname.length)) { printf("%.*s\n",newname); } return 1; } well unfortunatly that code gives an memory access error, but i have managed to get it to run, but i get the following error... Error 42: Symbol Undefined _GetComputerNameA 12 --- errorlevel 1 does that mean it couldnt find the function address in the dll? after 12 hours of trying to get D to print my computer name out, im certain i have a long road ahead :) however, im persistent an stubborn ;o)
Dec 13 2003
"Lewis" <dethbomb hotmail.com> wrote in message news:breiub$7a2$2 digitaldaemon.com...well unfortunatly that code gives an memory access error, but i haveOops, had the second parameter declaration wrong. extern (Windows): int GetComputerNameA(char *lpBuffer,uint* nSize); int main( char [] [] args ) { char[] newname = new char[255]; uint length; length = newname.length; if (GetComputerNameA(newname, &length)) { printf("%.*s\n",newname[0 .. length]); } return 1; }managed to get it to run, but i get the following error... Error 42: Symbol Undefined _GetComputerNameA 12 --- errorlevel 1 does that mean it couldnt find the function address in the dll?The linker doesn't look at dll's. It looks at .lib files. To see which lib a name is in, grep the .lib file for the name. For example, GetComputerNameA is in \dm\lib\kernel32.lib. Make sure you're linking that in.
Dec 13 2003
ok, somebody stop me when i get way out in left field :)
All these linker, header, libs an stuff is cause for a headache to a vb
programmer :( ... but it slowly starting to making sense.
My assumption at the moment is that the .lib files are (somewhat)
analagous to vb's typelib files in that they give the compiler a
template to call the dll with? header files are all to define datatypes
and function templates, so that the compiler can do compile time type
checking...?
right now im attempting to see if a theory i have (that libs create a
static link to a dll as opposed to a dynamic link) that i can define
several dll calls once to dynamicly load a library and then store
function pointers in public variables to the address's of the functions
in the dll, by calling (psuedo example) "LoadLibrary("DllName")" *if not
loaded already* and Address = LoadFunctionAddress("FunctionName")
now my question is, can i store these function address's in a delegate
or what would be the best way? and also what are the advantages of
dynamic loading (and linking) with windows dll's over static linking
with "libs"?
Dec 14 2003
WoW... it worked!! Now i only have to link to two library's and i can call
any dll function :) I have pasted my code below for critique if someone
has any suggestions on how to make it better... I have code my first D
program without help :) as mickeyD's would say "Im Loving It!!"
import std.c.stdio;
extern (Windows): int LoadLibraryA (char *lpLibFileName);
extern (Windows):int CallWindowProcA(int lpPrevWndProc,int hWnd,char*
Msg,char* wParam,int lParam);
extern (Windows): int GetProcAddress(int hModule,char *lpProcName);
extern (Windows):int GetModuleHandleA(char *lpModuleName);
int main( char [] [] args ) {
auto char[] Msg = "You Have Dynamically Loaded This MessageBox!!";
auto char[] Title = "Cool Message Box Title";
auto char[] LibraryName = "user32";
auto char[] FunctionName = "MessageBoxA";
auto int FunctionAddress;
auto int Success;
try {
FunctionAddress = DynamicLoad(LibraryName,FunctionName);
if ( FunctionAddress != 0 ) {
Success = CallWindowProcA(FunctionAddress,0,Msg,Title,0);
}
}
catch (Object e) {
printf("%s\n",e.toString);
}
return 0;
}
int DynamicLoad(char[] LibName,char[] FuncName) {
auto int hLib;
int hProc;
hLib = GetModuleHandleA(LibName);
if ( hLib == 0 ) {
hLib = LoadLibraryA(LibName);
}
if ( hLib == 0) {
return 0;
}
else {
hProc = GetProcAddress(hLib, FuncName);
}
return hProc;
}
Dec 14 2003
Not completely general since you still have to know a priori what parameters
the function takes. To do this for real you'd want to save and call thru
function pointers (with correct parameters!), not use int's.
I'm not sure why you have all the "auto" keywords everywhere. That's really
only useful for class variables... nothing else has a 'destructor'. You
shouldn't need to use auto on int's and char[]'s and such. GC already
handles all that.
Glad you're liking D. Now, if we can get more libraries so we don't have to
code to the Win32 api directly, that'll be great. ;)
Sean
"Lewis" <dethbomb hotmail.com> wrote in message
news:brjjqm$1lci$3 digitaldaemon.com...
WoW... it worked!! Now i only have to link to two library's and i can call
any dll function :) I have pasted my code below for critique if someone
has any suggestions on how to make it better... I have code my first D
program without help :) as mickeyD's would say "Im Loving It!!"
import std.c.stdio;
extern (Windows): int LoadLibraryA (char *lpLibFileName);
extern (Windows):int CallWindowProcA(int lpPrevWndProc,int hWnd,char*
Msg,char* wParam,int lParam);
extern (Windows): int GetProcAddress(int hModule,char *lpProcName);
extern (Windows):int GetModuleHandleA(char *lpModuleName);
int main( char [] [] args ) {
auto char[] Msg = "You Have Dynamically Loaded This MessageBox!!";
auto char[] Title = "Cool Message Box Title";
auto char[] LibraryName = "user32";
auto char[] FunctionName = "MessageBoxA";
auto int FunctionAddress;
auto int Success;
try {
FunctionAddress = DynamicLoad(LibraryName,FunctionName);
if ( FunctionAddress != 0 ) {
Success = CallWindowProcA(FunctionAddress,0,Msg,Title,0);
}
}
catch (Object e) {
printf("%s\n",e.toString);
}
return 0;
}
int DynamicLoad(char[] LibName,char[] FuncName) {
auto int hLib;
int hProc;
hLib = GetModuleHandleA(LibName);
if ( hLib == 0 ) {
hLib = LoadLibraryA(LibName);
}
if ( hLib == 0) {
return 0;
}
else {
hProc = GetProcAddress(hLib, FuncName);
}
return hProc;
}
Dec 15 2003
Sean L. Palmer wrote:Not completely general since you still have to know a priori what parameters the function takes. To do this for real you'd want to save and call thru function pointers (with correct parameters!), not use int's. I'm not sure why you have all the "auto" keywords everywhere. That's really only useful for class variables... nothing else has a 'destructor'. You shouldn't need to use auto on int's and char[]'s and such. GC already handles all that. Glad you're liking D. Now, if we can get more libraries so we don't have to code to the Win32 api directly, that'll be great. ;) SeanThanks for the tips! anything like that helps alot since i have alot to learn when it comes to learning how memory is managed from D, and what keywords actually do.
Dec 15 2003