How can I implement the following Windows function in Delphi?
HRESULT URLDownloadToFile(
LPUNKNOWN pCaller,
LPCTSTR szURL,
LPCTSTR szFileName,
DWORD dwReserved,
LPBINDSTATUSCALLBACK lpfnCB
);
URLDownloadToFile Function: http://msdn.microsoft.com/en-us/library/ms775123(VS.85).aspx
The question that prompted me was asked here.
Downloading flv from youtube using curlpp on top of curl - video not playing
Regards, Pieter.
uses
URLMon, ShellApi;
function DownloadFile(SourceFile, DestFile: string): Boolean;
begin
try
Result := UrlDownloadToFile(nil, PChar(SourceFile), PChar(DestFile), 0, nil) = 0;
except
Result := False;
end;
end;
Without header file we can not know what is LPBINDSTATUSCALLBACK for example. The best approach is to google around if someone has already made a conversion of the whole header file. If there isn't one, then try some C to Delphi convertor (http://www.drbob42.com/delphi/headconv.htm, http://cc.embarcadero.com/item/26951). Beware that they can only convert 60-80% of the code, but hopefully part you are interested in will be converted. If you are still stuck after all this, then search for VB conversion of the header. It will be much easier then conversion from C.
Related
I have been asked to correct an issue (not related to this question) in a legacy Delphi program. After fixing some issues with missing components, I am now stuck with some GDI Plus functionality, which stops me from compiling the program. One of the functions where this is used is:
function TDownLoadItem.LoadRawBitmapFromStream(var bm: TBitmap): Boolean;
var
image: TGPBitmap;
begin
Result := False;
if Content.Size = 0 then
exit;
// NOTE: Content is a TMemoryStream, declared globally.
image := GDIPlusHelper.LoadBitmapFromStream(Content); // <== This is where the problem is....
try
bm.Width := image.GetWidth;
bm.Height := image.GetHeight;
with TGPGraphics.Create(bm.Canvas.Handle) do
try
DrawImage(image, 0, 0, image.GetWidth, image.GetHeight);
Result := True;
finally
Free;
end;
finally
image.Free;
end;
end;
I think (not sure) the last Delphi version used was 2006, I am on Delphi Rio 10.3.
Online I have managed to find GDI+ 1.2, but this does not solve the problem. The procedure LoadBitmapFromStream does not exit in these libraries. GDIPlusHelper was apparently renamed to GDIPlusHelpers and most code has changed from classes to interfaces. I suspect an older edition of the GDI Plus libraries were used, but I cannot find these.
Reworking the code would be too complex as it would require Content to be an IStream instead of a TMemoryStream. Also, simply using a TBitmap is not feasible either as other code (not shown) uses functionality specific to TGPBitmap (e.g. RotateFlip).
Any suggestions on how to fix/work around this? Thanks in advance!
I am working with an API that provides me with the URL of a file and I wish to download the file to file or stream using Delphi XE.
The URL is in this form:-
https://xxxxxxx.s3-us-west-2.amazonaws.com/xxx/Reports/414_20160114021919.pdf?AWSAccessKeyId=xxxxxxxxxxxxxx&Expires=1478915858&response-content-disposition=attachment%3Bfilename%3D%22123%20Test%20St%20Dallas__2016_01_14_03_16_00.pdf%22&Signature=xxxxxxxxxxx%3D
where I have xxxxxxxxx'ed out the sensitive security stuff.
If I paste the URL into Chrome, it finds the file and brings up the save dialog.
In my Delphi Program I'm using URLMon with the following code (happily burgled and adapted from answers to similar questions here on SO) :-
function TdmXXXXXXXXX.DownloadFile(AURL, AExtWithDot: string): string;
// returns temp file name or empty string if failed;
var
sTempFileName: string;
iError: integer;
begin
sTempFileName := apmDM.GetTempFileName(AExtWithDot, True);
iError := UrlDownloadToFile(nil, PChar(AURL), PChar(sTempFileName), 0, nil);
if iError = S_OK then
Result := sTempFileName
else
Result := '';
showmessage(SysUtils.IntToHex(iError,8));
end;
The showmessage returns "800C000D"
In URLMon:-
$EXTERNALSYM INET_E_UNKNOWN_PROTOCOL}
INET_E_UNKNOWN_PROTOCOL = HResult($800C000D);
So I'm assuming that the problem relates to stuff after the "?" in the URL, "AWSAccessKeyId=" etc.
Not sure where to go from here - searched here and with Mr Google ...
Cheers
Jeff
Though you'll typically find pointers to the Indy TIdHTTP component, my personal favorite is including the Microsoft XML library (MSXML2_TLB), and using the XmlHTTPRequest component. If you use a TStreamAdapter on it's responseStream property, you'll have a stream to a resource over an URL.
I scratched all that I had done and restarted from scratch.
It all worked using URLMon and
URLDownloadToFile(nil, PChar(sReportURL), PChar(sTempFileName), 0, nil);
I have pored over the code and can't see any difference between reported problem code and my final code.
I'm using both old good MPGTools and own, simple method of setting ID3 Tag in my MP3 files. But both approaches are too old to support ID3Tag version 2. I'm looking for any solution that would allow my application, written in Delphi 7, to either remove ID3Tag from each file it process or to set it to exactly the same values as ID3Tag version 1 is set.
Currently I'm removing ID3Tagv2 manually, using quick keyboard combination in Winamp.
I don't use v2 or album art or all these "new" addition, so the quickiest way to get rid of ID3Tagv2 (if it exists in particular file) would be all I need.
Of course I've tried to search the Internet using Google, but either I've got bad day or I'm asking wrong question, because all the results I'm getting on above mentioned questions are fake result from search engine stealers like Software Informer etc.
As it happens, one of my projects sitting here that is awaiting completion (about 80%, I'm more a hobbyist when it comes to Delphi and had more pressing stuff come up, then I found a program I was able to download which fit my requirements precisely) is a full ID3 tag editor for MP3 files. While v1 was super-easy, v2 is much harder. You can refer to the standard document for v2.3 here.
But I will confine myself to the points addressed here.
You might want ID3v2 tags depending on the application. My portable MP3 player only accepts v2 tags, which is what pushed me to do the project in the first place.
ID3v2 tags are written at the beginning of files in a variable length manner with variable numbers of tags which may or may not be present. Fortunately, the full length of the data should be in the first record if it's an ID3v2 tagged file. Hence, read the file locate the length of the ID3v2 data, then rewrite the file without the ID3v2 data and the tags are removed. Having the data at the beginning makes this necessary and is indeed a frustration. Anything I do in the future to the code would involve trying to change data in place. Some very dirty code follows, which AFAIR worked, but you will need to clean up if you use (I'm sure some here will be content to point out exactly how I should). But test it well just to be sure. Also be sure to ask if I missed anything from the unit I copied this out of (it's a 19.3KB pas file) that you would need:
type
sarray = array[0..3] of byte;
psarray = ^sarray;
ID3v2Header = packed record
identifier: array[0..2] of char;
major_version: byte;
minor_version: byte;
flags: byte;
size: DWord;
end;
function size_decodeh(insize: DWord): DWord;
{ decodes the size headers only, which does not use bit 7 in each byte,
requires MSB conversion as well }
var
outdval: DWord;
outd, ind: psarray;
tnext2, pnext2: byte;
begin
outdval := 0;
outd := #outdval;
ind := #insize;
tnext2 := ind^[2] shr 1;
pnext2 := ind^[1] shr 2;
outd^[0] := ind^[3] or ((ind^[2] and $01) shl 7);
outd^[1] := tnext2 or ((ind^[1] and $03) shl 6);
outd^[2] := pnext2 or ((ind^[0] and $07) shl 5);
outd^[3] := ind^[0] shr 3;
Result := outdval;
end;
procedure ID3v2_LoadData(filename: string; var memrec: pointer;
var outsize: integer);
{ procedure loads ID3v2 data from "filename". Returns outsize = 0 if
there is no ID3v2 data }
var
infile: file;
v1h: ID3V2Header;
begin
assign(infile, filename);
reset(infile, 1);
// read main header to get id3v2 size
blockread(infile, v1h, sizeof(v1h));
// detect if there is id3v2 data
if v1h.identifier = 'ID3' then
begin
outsize := size_decodeh(v1h.size);
// read ID3v2 header data
getmem(memrec, outsize);
blockread(infile, memrec^, outsize);
Close(infile);
end
else
outsize := 0;
end;
function id3v2_erase(infilestr: string): boolean;
{ erase all ID3v2 data. Data are stored at the beginning of file, so file
must be rewritten }
const
tempfilename = 'TMp#!0X.MP3';
var
memrec: pointer;
outsize, dataread: integer;
IsID3v2: boolean;
databuffer: array[1..32768] of byte;
newfile, origfile: file;
begin
// reuse service routine to get information
Id3v2_loaddata(infilestr, memrec, outsize);
// is there ID3v2 data?
if outsize > 0 then
begin
// need to clean up after the service routine
freemem(memrec);
// get amount of data to erase
outsize := outsize + sizeof(Id3v2Header);
writeln('Data to delete is: ', outsize, ' bytes.');
// now rewrite the file
AssignFile(origfile, infilestr);
reset(origfile, 1);
AssignFile(newfile, tempfilename);
rewrite(newfile, 1);
Seek(origfile, outsize);
repeat
blockread(origfile, databuffer, sizeof(databuffer), dataread);
blockwrite(newfile, databuffer, dataread);
until dataread = 0;
CloseFile(origfile);
CloseFile(newfile);
// rename temp file and delete original
DeleteFile(infilestr);
RenameFile(tempfilename, infilestr);
IsID3v2 := true;
end
else
IsID3v2 := false;
Result := IsID3v2;
end;
Full editing capability that works in most all situations is obviously a tougher hill to climb than that, but all the details are there in that document I linked to. Hopefully this helps you out.
There are few libs that works fine with ID3V2. Back in 2006 I did a big research to find Delphi library that supports most of the Id3V2 specification for Delphi 7.
And I found these 2:
Audio Tools Library (was the best for that moment). I think that it even could read/write tags in Unicode. Here is the unit Id3V2.pas
JVCL has component to work with Id3V2 tags. But it didn't had Unicode support for non-unicode Delphi in 2006.
Btw, if you do not use JVCL yet, it's not worth to install more than 600 components just to get Id3V2 support.
So, take a look at Audio Tools Library.
First of all: this is not a duplicate of Delphi and SAPI. I have a specific problem with the "SAPI in Delphi" subject.
I have used the excellent Import Type-Library guide in Delphi 2009 to get a TSpVoice component in the component palette. This works great. With
var
SpVoice: TSpVoice;
I can write
SpVoice.Speak('This is an example.', 1);
to get asynchronous audio output.
First question
According to the documentation, I would be able to write
SpVoice.Speak('This is an example.', 0);
to get synchronous audio output, but instead I get an EZeroDivide exception. Why's that?
Second question
But more importantly, I would like to be able to create the SpVoice object dynamically (I think this is called to "late-bind" the SpVoice object), partly because only a very small fraction of all sessions of my app will use it, and partly because I do not want to assume the existance of the SAPI server on the end-user's system.
To this end, I tried
procedure TForm1.FormClick(Sender: TObject);
var
SpVoice: Variant;
begin
SpVoice := CreateOleObject('SAPI.SpVoice');
SpVoice.Speak('this is a test', 0);
end;
which apparently does nothing at all! (Replacing the 0 with 1 gives me the EZeroDivide exception.)
Disclaimer
I am rather new to COM/OLE automation. I am sorry for any ignorance or stupidity shown by me in this post...
Update
For the benefit of everyone encountering the same problem as I did, the video by François explained there is a bug in SAPI/Windows (some incompatibility somewhere), which makes the following code raise the EZeroDivide exception:
procedure TForm1.FormClick(Sender: TObject);
var
SpVoice: variant;
begin
SpVoice := CreateOleObject('SAPI.SpVoice');
SpVoice.Speak('This is a text.');
end;
The solution, as presented by the video, is to alter the FPU control word:
procedure TForm1.FormClick(Sender: TObject);
var
SpVoice: variant;
SavedCW: Word;
begin
SpVoice := CreateOleObject('SAPI.SpVoice');
SavedCW := Get8087CW;
Set8087CW(SavedCW or $4);
SpVoice.Speak('This is a text.');
Set8087CW(SavedCW);
end;
And, in addition, if you want to play a sound asynchronously, then you have to make sure that the player doesn't go out of scope!
You may find interesting to see this CodeRage 4 session on "Speech Enabling Delphi Applications (zip)"
You'll get the "how-to" you're looking for...
(and I guess you are on Vista or + as the the zero divide did not happend on XP)
I was having the same problem in Delphi XE2. The Set8087CW(SavedCW or $4) solution presented in the question did not work for me. It merely replaced the division by zero exception with another floating point exception.
What did work for me is this:
SavedCW := Get8087CW;
SetFPUExceptionMask([exInvalidOp, exDenormalized, exZeroDivide, exOverflow, exUnderflow, exPrecision]);
SpVoice.Speak('All floating point exceptions disabled!', 0);
Set8087CW(SavedCW);
Delphi 2010 has a nice set of new file access functions in IOUtils.pas (I especially like the UTC versions of the date-related functions). What I miss so far is something like
TFile.GetSize (const Path : String)
What is the Delphi 2010-way to get the size of a file? Do I have to go back and use FindFirst to access TSearchRec.FindData?
Thanks.
I'm not sure if there's a "Delphi 2010" way, but there is a Windows way that doesn't involve FindFirst and all that jazz.
I threw together this Delphi conversion of that routine (and in the process modified it to handle > 4GB size files, should you need that).
uses
WinApi.Windows;
function FileSize(const aFilename: String): Int64;
var
info: TWin32FileAttributeData;
begin
result := -1;
if NOT GetFileAttributesEx(PChar(aFileName), GetFileExInfoStandard, #info) then
EXIT;
result := Int64(info.nFileSizeLow) or Int64(info.nFileSizeHigh shl 32);
end;
You could actually just use GetFileSize() but this requires a file HANDLE, not just a file name, and similar to the GetCompressedFileSize() suggestion, this requires two variables to call. Both GetFileSize() and GetCompressedFileSize() overload their return value, so testing for success and ensuring a valid result is just that little bit more awkward.
GetFileSizeEx() avoids the nitty gritty of handling > 4GB file sizes and detecting valid results, but also requires a file HANDLE, rather than a name, and (as of Delphi 2009 at least, I haven't checked 2010) isn't declared for you in the VCL anywhere, you would have to provide your own import declaration.
Using an Indy unit:
uses IdGlobalProtocols;
function FileSizeByName(const AFilename: TIdFileName): Int64;
You can also use DSiFileSize from DSiWin32. Works in "all" Delphis. Internally it calls CreateFile and GetFileSize.
function DSiFileSize(const fileName: string): int64;
var
fHandle: DWORD;
begin
fHandle := CreateFile(PChar(fileName), 0, 0, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
if fHandle = INVALID_HANDLE_VALUE then
Result := -1
else try
Int64Rec(Result).Lo := GetFileSize(fHandle, #Int64Rec(Result).Hi);
finally CloseHandle(fHandle); end;
end; { DSiFileSize }
I'd like to mention few Pure Delphi ways. Though i think Deltics made a most speed-effective answer for Windows platform, yet sometimes you want just rely on RTL and also make portable code that would work in Delphi for MacOS or in FreePascal/Virtual Pascal/whatever.
There is FileSize function left from Turbo Pascal days.
http://turbopascal.org/system-functions-filepos-and-filesize
http://docwiki.embarcadero.com/CodeExamples/XE2/en/SystemFileSize_(Delphi)
http://docwiki.embarcadero.com/Libraries/XE2/en/System.FileSize
The sample above lacks "read-only" mode setting. You would require that to open r/o file such as one on CD-ROM media or in folder with ACLs set to r/o. Before calling ReSet there should be zero assigned to FileMode global var.
http://docwiki.embarcadero.com/Libraries/XE2/en/System.FileMode
It would not work on files above 2GB size (maybe with negative to cardinal cast - up to 4GB) but is "out of the box" one.
There is one more approach, that you may be familiar if you ever did ASM programming for MS-DOS. You Seek file pointer to 1st byte, then to last byte, and check the difference.
I can't say exactly which Delphi version introduced those, but i think it was already in some ancient version like D5 or D7, though that is just common sense and i cannot check it.
That would take you an extra THandle variable and try-finally block to always close the handle after size was obtained.
Sample of getting length and such
http://docwiki.embarcadero.com/Libraries/XE2/en/System.SysUtils.FileOpen
http://docwiki.embarcadero.com/Libraries/XE2/en/System.SysUtils.FileSeek
Aside from 1st approach this is int64-capable.
It is also compatible with FreePascal, though with some limitations
http://www.freepascal.org/docs-html/rtl/sysutils/fileopen.html
You can also create and use TFileStream-typed object - which was the primary, officially blessed avenue for file operations since Delphi 1.0
http://www.freepascal.org/docs-html/rtl/classes/tfilestream.create.html
http://www.freepascal.org/docs-html/rtl/classes/tstream.size.html
http://docwiki.embarcadero.com/Libraries/XE2/en/System.Classes.TFileStream.Create
http://docwiki.embarcadero.com/Libraries/XE2/en/System.Classes.TStream.Size
As a side note, this avenue is of course integrated with aforementioned IOUtils unit.
http://docwiki.embarcadero.com/Libraries/XE3/en/System.IOUtils.TFile.OpenRead
This is a short solution using FileSize that does the job:
function GetFileSize(p_sFilePath : string) : Int64;
var
oFile : file of Byte;
begin
Result := -1;
AssignFile(oFile, p_sFilePath);
try
Reset(oFile);
Result := FileSize(oFile);
finally
CloseFile(oFile);
end;
end;
From what I know, FileSize is available only from XE2.
uses
System.Classes, System.IOUtils;
function GetFileSize(const FileName : string) : Int64;
var
Reader: TFileStream;
begin
Reader := TFile.OpenRead(FileName);
try
result := Reader.Size;
finally
Reader.Free;
end;
end;