How to get the file URL from absolute path in Delphi? - delphi

I'm looking for a Delphi function which returns the file URL path from the Windows path. Is there something for it built-in in Delphi ?
Example:
Input
C:\Users\Documents\File.txt
Output
file:///C:/Users/Documents/File.txt
Thanks

You can use the UrlCreateFromPath API function.Here is the example:
uses
ComObj, WinInet, ShLwApi;
function FilePathToURL(const FilePath: string): string;
var
BufferLen: DWORD;
begin
BufferLen := INTERNET_MAX_URL_LENGTH;
SetLength(Result, BufferLen);
OleCheck(UrlCreateFromPath(PChar(FilePath), PChar(Result), #BufferLen, 0));
SetLength(Result, BufferLen);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(FilePathToURL('C:\Users\Documents\File.txt'));
end;

Look at UrlCreateFromPath(). Note that there are caveats with the file: scheme, though. It is not stanardized across platforms. There are multiple formats to represent the same path in different ways, even just under Windows. Since IE4, the Win32 API standardizes on a single format, but other formats still exist.

Related

Delphi Clipboard: Read file properties of a file copied

I would like to retrieve the file size of a file copied into the clipboard.
I read the documentation of TClipboard but I did not find a solution.
I see that TClipboard.GetAsHandle could be of some help but I was not able to complete the task.
Just from inspecting the clipboard I could see at least 2 useful formats:
FileName (Ansi) and FileNameW (Unicode) which hold the file name copied to the clipboard.
So basically you could register one of then (or both) with RegisterClipboardFormat and then retrieve the information you need. e.g.
uses Clipbrd;
var
CF_FILE: UINT;
procedure TForm1.FormCreate(Sender: TObject);
begin
CF_FILE := RegisterClipboardFormat('FileName');
end;
function ClipboardGetAsFile: string;
var
Data: THandle;
begin
Clipboard.Open;
Data := GetClipboardData(CF_FILE);
try
if Data <> 0 then
Result := PChar(GlobalLock(Data)) else
Result := '';
finally
if Data <> 0 then GlobalUnlock(Data);
Clipboard.Close;
end;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
if Clipboard.HasFormat(CF_FILE) then
ShowMessage(ClipboardGetAsFile);
end;
Once you have the file name, just get it's size or other properties you want.
Note: The above was tested in Delphi 7. for Unicode versions of Delphi use the FileNameW format.
An alternative and more practical way (also useful for multiple files copied) is to register and handle the CF_HDROP format.
Here is an example in Delphi: How to paste files from Windows Explorer into your application

Delphi XE6: How to enumerate RCData resource names?

I have embedded several resources into the executable, for instance language (text) files.
Below you can see the contents of Languages.rc file:
Language_English RCDATA Languages\English.ini
Language_German RCDATA Languages\German.ini
Language_Czech RCDATA Languages\Czech.ini
I found this answer, which definitely helps, however I have rather hard time implementing it.
Suppose you want to get the list of those resources as a EOL-delimited string, then the first step would be defining EnumRCDataProc function:
function EnumRCDataProc(hModule: HMODULE; lpszType, lpszName: PChar; lParam: NativeInt): BOOL; stdcall;
begin
TStrings(lParam).Add(lpszName);
Result := True;
end;
Once we have that done, we can get to work:
function EnumerateRCDataResourceNames: string;
var
ExecutableHandle: HMODULE;
ResourcesList: TStringList;
begin
ExecutableHandle := LoadLibraryEx(PChar(Application.ExeName), 0, LOAD_LIBRARY_AS_DATAFILE);
try
ResourcesList := TStringList.Create;
try
EnumResourceNames(ExecutableHandle, RT_RCDATA, #EnumRCDataProc, NativeInt(ResourcesList));
Result := ResourcesList.Text;
finally
ResourcesList.Free;
end;
finally
FreeLibrary(ExecutableHandle);
end;
end;
Remarks:
As is in the original answer (see question), it is not possible to use LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE or LOAD_LIBRARY_AS_IMAGE_RESOURCE as these types are no longer defined in Delphi XE6, at least AFAIK.
You can, however, define those constants, according to MSDN:
LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE = $00000040
LOAD_LIBRARY_AS_IMAGE_RESOURCE = $00000020

what causes this error 'Unable to write to application file.ini'

My application is build in delphi and it runs perfect on other platforms except Windows 7 64bit machine. Each and everytime try to close the application is giving me this error
'Unable to write to application file.ini'
here is my code for closing
procedure TfrmMain.FormClose(Sender: TObject; var Action: TCloseAction);
begin
frmMain.close;
end;
This error is usually caused by trying to write to your app's own folder under Program Files, which is not allowed for a non-Administrator under Vista and higher (and XP, if you're not running as an Administrator or Power User).
Here's some code for getting the proper folder for your .INI file:
uses
Windows,
ShlObj; // For SHGetSpecialFolderPath
function GetFolderLocation(Handle: HWnd; Folder: Integer): string;
begin
Result := '';
SetLength(Result, MAX_PATH);
if not SHGetSpecialFolderPath(Handle, PChar(Result), Folder, False) then
RaiseLastOSError;
end;
I use these in my application to retrieve the non-roaming profile folder, and use a sub-folder created beneath that for my app's data. It's set up during the creation of a TDataModule:
procedure TAppData.Create(Sender.TObject);
begin
// DataPath is a property of the datamodule, declared as a string
// CSIDL_LOCAL_APPDATA is the local non-roaming profile folder.
// CSIDL_APPDATA is for the local roaming profile folder, and is more typically used
DataPath := GetFolderLocation(Application.Handle, CSIDL_LOCAL_APPDATA);
DataPath := IncludeTrailingPathDelimiter(DataPath) + 'MyApp\';
end;
See MSDN's documentation page on the meaning of the various CSIDL_ or FOLDERID_ values. The FOLDERID_ values are similar, but are available only on Vista and above and used with SHGetKnownFolderIDList.
For those of you not willing to disregard MS's warnings about SHGetSpecialFolderPath not being supported, here's an alternate version of GetFolderLocation using SHGetFolderPath, which is preferred:
uses
ShlObj, SHFolder, ActiveX, Windows;
function GetFolderLocation(Handle: HWnd; Folder: Integer): string;
begin
Result := '';
SetLength(Result, MAX_PATH);
if not Succeeded(SHGetFolderPath(Handle, Folder, 0, 0, PChar(Result))) then
RaiseLastOSError();
end;
And finally, for those working with only Vista and higher, here's an example using SHGetKnownFolderPath - note this isn't available in pre-XE versions of Delphi (AFAIK-may be in 2009 or 2010), and you'll need to use KNOWNFOLDERID values instead of CSIDL_, like FOLDERID_LocalAppData:
uses
ShlObj, ActiveX, KnownFolders;
// Tested on XE2, VCL forms application, Win32 target, on Win7 64-bit Pro
function GetFolderLocation(const Folder: TGuid): string;
var
Buf: PWideChar;
begin
Result := '';
if Succeeded(SHGetKnownFolderPath(Folder, 0, 0, Buf)) then
begin
Result := Buf;
CoTaskMemFree(Buf);
end
else
RaiseLastOSError();
end;
You should not write ini files to the program directory. Although it worked in the past, it has never been a good practice.
You should be using %APPDATA% for user specific application data.
You might want to read Best practices storing application data

Get Application exe size easily

Is there a way in Delphi to get the currect application's exe size in one or two lines of code?
Just for grins...you can also do this with streams Just slightly more than 2 lines of code. Generally the application filename including path is also stored into Paramstr(0).
var
fs : tFilestream;
begin
fs := tFilestream.create(paramstr(0),fmOpenRead or fmShareDenyNone);
try
result := fs.size;
finally
fs.free;
end;
end;
It's not as small as you want, but it needs no handles. I use this in all my "SFX" archivers and programs that must know their size. IIRC it requires the Windows unit.
function GetExeSize: cardinal;
var
p: pchar;
i, NumSections: integer;
const
IMAGE_PE_SIGNATURE = $00004550;
begin
result := 0;
p := pointer(hinstance);
inc(p, PImageDosHeader(p)._lfanew + sizeof(dword));
NumSections := PImageFileHeader(p).NumberOfSections;
inc(p,sizeof(TImageFileHeader)+ sizeof(TImageOptionalHeader));
for i := 1 to NumSections do
begin
with PImageSectionHeader(p)^ do
if PointerToRawData+SizeOfRawData > result then
result := PointerToRawData+SizeOfRawData;
inc(p, sizeof(TImageSectionHeader));
end;
end;
For the sake of future compatibility, you should choose an implementation that does not require pointers or Windows API functions when possible. The TFileStream based solution provided by skamradt looks good to me.
But... You shouldn't worry too much whether the routine is 1 or 10 lines of code, because you're going to encapsulate it anyway in a function that takes a filename as a parameter and returns an Int64, and put it in your personal library of reusable code. Then you can call it like so:
GetMyFileSize(Application.ExeName);
You can try this:
if FindFirst(ExpandFileName(Application.exename), faAnyFile, SearchRec) = 0 then
MessageDlg(Format('Tamaño: <%d>',[SearchRec.Size]), mtInformation, [mbOK], 0);
FindClose(SearchRec);
===============
Neftalí
Streams can also be used without a TFileStream variable:
with TFilestream.create(paramstr(0), fmOpenRead or fmShareDenyNone) do
aFileSize := Size;
Free;
end;
Ugly, yes.
I prefer using DSiFileSize from DSiWin32. It uses CreateFile internally:
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 }
Unfortunatly it is not possible to do that with only one or two lines of code without using some library.
The easy part is getting the application's exe file. You can find it in Application.ExeName
In general there are several possibilities for retrieving the file size:
Open the file and read the size of the stream. This can be accomplished using the 'old' Delphi functions FileOpen and FileSize, or with TFileStream (use the size property) or with Win32 API functions CreateFile and GetFileSize function. (Platform dependend!) Make sure you open the file with read-only access.
In a pure Win32 envinronment you can use FindFirst to get the file size. You can read it from TSearchRec.FindData.nFileSizeLow. If you want to be prepared for files larger than 2 GB (you should be) you have to use also the nFileSizeHigh part.
In Delphi.NET you can use the System.IO.FileInfo, like this: FileInfo.Create(filename).Length (one-liner)
In Linux you can use the lstat64 function (Unit Libc) and get the size from TStatBuf64.st_size. (two-liner if you don't count the variable declaration)
In the JCL library you can find many useful functions, including a simple function which returns the file size of a given file name. (It uses a method which suits the given platform)
uses IdGlobalProtocols;
var
ExeSize: Int64;
begin
ExeSize := FileSizeByName(ParamStr(0));
// or
ExeSize := FileSizeByName(Application.ExeName);
end;
I would like to modify the code provided by skamradt, to make it two lines of code as you requested ;-)
with tFilestream.create(paramstr(0),fmOpenRead or fmShareDenyNone) do
ShowMessage(IntToStr(size));
but I would prefer to use the code as skamradt wrote, because it's more safe
Shortest I could do. Note that the .Size is in bytes, so for kilobytes, divide by 1024.
procedure TForm1.Button1Click(Sender: TObject);
begin
with TFileStream.Create(Application.ExeName,fmShareDenyNone) do
ShowMessage(FloatToStr(Size/1024));
end;
Check out this link.

File MD5 checksum

In this question is mentioned the wcrypt2.
What I need is simply calculate the MD5 of a file. It would be perfect if I could calculate it without having to save it because it is a downloaded file in stream format.
I would like to have the most straightforward way to do that.
Thanks!
Here is a working code for Indy 10:
function MD5File(const FileName: string): string;
var
IdMD5: TIdHashMessageDigest5;
FS: TFileStream;
begin
IdMD5 := TIdHashMessageDigest5.Create;
FS := TFileStream.Create(FileName, fmOpenRead or fmShareDenyWrite);
try
Result := IdMD5.HashStreamAsHex(FS)
finally
FS.Free;
IdMD5.Free;
end;
end;
Regards,
OscaR1
Based on #dummzeuch answere I wrote this function:
function getMD5checksum(s: TStream): string;
var
md5: TIdHashMessageDigest5;
hash : T4x4LongWordRecord;
begin
md5 := TIdHashMessageDigest5.Create;
s.Seek(0,0);
hash := md5.HashValue(s);
result := IntToHex(Integer(hash[0]), 4) +
IntToHex(Integer(hash[1]), 4) +
IntToHex(Integer(hash[2]), 4) +
IntToHex(Integer(hash[3]), 4);
end;
Indy comes with functions for calculating several hashes, MD5 is one of them. Indy is included in all versions of Delphi since at least Delphi 2006 and available as a free download for older versions.
What about:
function GetFileMD5(const Stream: TStream): String; overload;
var MD5: TIdHashMessageDigest5;
begin
MD5 := TIdHashMessageDigest5.Create;
try
Result := MD5.HashStreamAsHex(Stream);
finally
MD5.Free;
end;
end;
function GetFileMD5(const Filename: String): String; overload;
var FileStream: TFileStream;
begin
FileStream := TFileStream.Create(FileName, fmOpenRead or fmShareDenyWrite);
try
Result := GetFileMD5(FileStream);
finally
FileStream.Free;
end;
end;
As you mentioned, the post you linked to talks about wcrypt2, which is a library of cryptographic routines, including MD5. The post you linked to also seems to indicate that it is available for Delphi 7 since the asker includes output labeled "Delphi 7." You have tagged this question delphi7, so I assume that's the version you're using, too. So what's stopping you from using wcrypt2?
The question links to a copy of wcrypt2.pas, and the copyright dates in that file appear to indicate that the unit was available by the time Delphi 7 was released. Check your installation; you might already have it. If not, then the unit also says that it was obtained via Project Jedi, so you could try looking there for the unit as well.
The answers to your referenced question include example Delphi code and the names of units that come with Delphi for doing MD5. They come with Delphi 2009, so you should check whether they're also available for your version.
Take a look at this implementation of MD5SUM in Delphi. It requires a string for input, but I imagine you can easily make it work with a stream.
MessageDigest_5 would work for this as well.
I use the following function in Delphi 7 with Indy 10.1.5
uses IdHashMessageDigest, idHash, Classes;
...
function cc_MD5File(const p_fileName : string) : string;
//returns MD5 has for a file
var
v_idmd5 : TIdHashMessageDigest5;
v_fs : TFileStream;
v_hash : T4x4LongWordRecord;
begin
v_idmd5 := TIdHashMessageDigest5.Create;
v_fs := TFileStream.Create(p_fileName, fmOpenRead OR fmShareDenyWrite) ;
try
v_hash := v_idmd5.HashValue(v_fs);
result := v_idmd5.AsHex(v_hash);
finally
v_fs.Free;
v_idmd5.Free;
end;
end;
If you use Overbyte http://www.overbyte.eu/frame_index.html just add unit and call function FileMD5 with name of file
uses OverbyteIcsMd5;
....
function GetMd5File:String;
begin
Result := FileMD5(FileName);
end;

Resources