I need to call windows DLL functions.
I’ve tried the example (MsgBox) and it’s working fine but…
I struggle to find how to call other methods that have different prototypes.
For example how can I call :
BOOL WINAPI GetUserName( Out LPTSTR lpBuffer, Inout LPDWORD lpnSize
);
I also miss information on what exactly is supported in HEScript.
PChar( ), array definitions, GetMemory() and others Delphi things for example produce syntax errors so I can’t find a way to allocate the char buffer…
This is the only thing actually that prevents me from buying the product for a client’s project.
Please help,
PChar is not used, the script engine treats them as “string”.
Here is a possible translation: function GetUserName(lpBuffer: string; nSize: LongWORD): BOOL; stdcall; external "Advapi32.dll" name 'GetUserNameW';
(not tested)
Another example we use in our demos: function GetEnvironmentVariable(lpName: string; lpBuffer: string; nSize: LongWORD): LongWORD; stdcall; external "kernel32.dll" name 'GetEnvironmentVariableA';
For Pascal syntax supported, please see a PM we sent you with a PDF file that explains how the script engine works.
In the « Main Demonstration » that comes with HTML Executable. You can download the source code with the Web Update utility.
Here is one of the scripts used:
// MiscFunctions
// Some functions used for our demonstration.
// Win32 API used to determine the %USERPROFILE% variable if required.
function GetEnvironmentVariable(lpName: string; lpBuffer: string; nSize: LongWORD): LongWORD; stdcall; external "kernel32.dll" name 'GetEnvironmentVariableA';
// Check if a file exists!
function SayHello: Boolean;
begin
MessageDlg("HTML Executable lets you add your own menu commands!", "HELLO!!", mtInformation, [mbOK]);
end;
procedure SayHello2(what: string);
begin
MessageDlg(ReplaceString(what, "%20", " "), "HELLO!!", mtInformation, [mbOK]);
end;
function GetDesktopImageHTMLPath: String;
var
a, i: integer;
S: String;
Path, Path2: String;
FilePath: String;
begin
Result := "Not supported.";
try
// a) Read the path to the desktop image file.
Path := ReadRegStr(hkCurrentUser, "Software\Microsoft\Internet Explorer\Desktop\General", "Wallpaper", "");
// If blank, then Active Desktop may not be set up.
if Path = "" then Path := ReadRegStr(hkCurrentUser, "Software\Microsoft\Internet Explorer\Desktop\General", "WallpaperSource", "");
if Path = "" then exit;
Path2 := "";
if Pos("%USERPROFILE%", UpperCase(Path)) > 0 then
begin
S := "";
a := GetEnvironmentVariable("USERPROFILE", S, 255);
Path2 := ReplaceString(Path, "%USERPROFILE%", "");
Path := Copy(S, 1, a);
end;
if Pos("%SYSTEMROOT%", UpperCase(Path)) > 0 then
begin
S := "";
a := GetEnvironmentVariable("SYSTEMROOT", S, 255);
Path2 := ReplaceString(Path, "%SYSTEMROOT%", "");
Path := Copy(S, 1, a);
end;
FilePath := Path + Path2;
if not fileexists(FilePath) then
begin
Result := "The desktop wallpaper file was not found!"
exit;
end;
Result := "<IMG SRC=""" + FilePath + """>";
except
Result := "An error occurred";
end;
end;
I think that it’s wrong because the second parameter of GetUserName is a in/out LPDWORD.
So Maybe
function GetUserName(lpBuffer: string; pSize: Pointer): BOOL; stdcall; external “Advapi32.dll” name ‘GetUserNameW’;
?
But how to get the pointer to size. ^ deferencing operator produces syntax error.
OK I missed the var statement in your post above (I thought it was a typo).
So
function GetUserName(lpBuffer: string; var pSize: LongWORD): BOOL; stdcall;
external "Advapi32.dll" name 'GetUserNameW';
S := " ";
Size := 255;
ret:= GetUserName(S, Size);
Seems to work. Note that if I don’t put a space into S (S := “”, like in your sample), I get a crash.
Mmm I don’t really understand how the string is allocated and what is its size…
I received a negative answer from the script engine developer, the GetUserName API can’t be used because DWORD pointers won’t work properly.
Anyway, you can get the user name from the registry: look at HKEY_CURRENT_USER\Volatile Environment - USERNAME.
Environment variables also contain useful data, and the API can be successfully imported.
It’s bad news though because lots of those “Get” functions use the DWORD pointer mecanism (for example I was also using GetComputerName and GetComputerNameEx).
