Delphi 7 - if I make a new project and add a line
spacePos := LastDelimiter(' ' , 'spaced out');
it builds.
If I try to use LastDelimiter in my own project it fails.
I started with a stamenet comparing LastDelimter(#$D#$A, myString) and wen that failed I tried with the lien above, which also failed.
I do use SysUtils, but that wasn't even necessary when I created a new project.
If I comment out that line my real project builds just fine. If I uncomment it I get "missing operator or semicolon". Same thing if I move the LastDelimiter to an assignment, even on the fist line of the function which it is in - it really doesn't look like a problem with a previous line.
Any ideas (short of me posting a few klocs)?
Thanks
Perhaps somewhere in your scope is a global variable defined similar to the following:
var
LastDelimiter: Integer;
Check the units used in your project. It should be a global variable declared in the interface section.
Or it could be a constant, declared in the interface section, similar to this:
const
LastDelimiter = 32;
You have learned what a namespace or identifier or "scope collision" is, today. Some unit in your implementation or interface uses clause, also defines LastDelimiter, and since it is the innermost or most recent declaration, it renders that particular identifier in SysUtils invisible until you specify the SysUtils prefix.
When you have namespace collisions, you should qualify the function name with its unit name, and it will then compile for you:
x := SysUtils.LastDelimiter( .... );
For this very reason, some developers who are comfortable with languages like C# and Java are used to always requiring namespaces to be specified, thus their code looks like this:
x := namespace.Thing1.Thing2.GetInput( ... );
Just because we don't always do that in Delphi doesn't mean there aren't times when you SHOULD be doing that.
Related
I have a TCustomClientDataSet (in memory) which is used to do some filtering in a Delphi program.
My filtering code look like :
CDSFilteredGroup.Filter := 'ACP_type = 1 AND ACP_by_default <> False';
CDSFilteredGroup.Filtered := True;
When I compile and run it, I got the following error only with Delphi (XE4) installed on my computer :
CDSFilteredGroup: Champ 'False' non trouvé.
Translation: Field 'False' not found. The same code compile and run perfectly fine on my colleagues computers, but not on mine. There must be an option somewhere that I miss, any idea ?
Remember, the code is ok and working...
The TExprParser instance used for handling the filter string relies on the resourcestrings given as STextTrue and STextFalse. You probably have another language than English configured for your IDE library. Try switching to English and see if the error disappears.
To workaround that problem in general replace the text "False" with the content of the resourcestring STextFalse.
BTW, this was corrected in later Delphi versions that also accept the literal "False" even in non English environments.
I am using XE8, win 8.1.
When trying load a file with spaces in directory, I am getting a exception of syntax name of the file or directory is invalid.
If I use imageen dialog to preview the file, no erros are found.
I did two tests with the procedure load_file1 and load_file2 and I have the same problem.
Is there a wrokaround to solve it?
function get_file:string;
begin
result:='"C:\Compartilhada\dicomserver versoes\dicomserverx\data\Genesis-1000\1.2.410.200013.1.215.1.200912141600580009_0001_000001_13061821270002.dcm"'
end;
procedure load_file1;
var fStm:Tstream;
p1:string;
begin
p1:=get_file;
fStm := tFileStream.Create( p1, fmOpenRead or fmShareDenyNone ); //->Error Here
try
TBlobField(FieldByName('dicom')).LoadFromStream(fStm);
Post;
finally
fSTm.Free;
end;
end;
procedure load_file2;
p1:string;
begin
p1:=get_file;
TBlobField(FieldByName('dicom')).LoadFromFile(p1); //-->Error Here
Post;
end;
Remove the double quote marks from your string. It should be:
'C:\Compartilhada\dicomserver versoes\dicomserverx\data\Genesis-1000\1.2.410.200013.1.215.1.200912141600580009_0001_000001_13061821270002.dcm'
You might use " for paths containing spaces in some situations, for instance a command interpreter. But at the API level, it is simply not needed. And indeed it is a mistake as you have discovered. The double quote character " is actually a reserved character in a file name. That is documented on MSDN:
Naming Files, Paths, and Namespaces: Naming Conventions
The following fundamental rules enable applications to create and process valid names for files and directories, regardless of the file system:
...
Use any character in the current code page for a name, including Unicode characters and characters in the extended character set (128–255), except for the following:
The following reserved characters:
< (less than)
> (greater than)
: (colon)
" (double quote)
/ (forward slash)
\ (backslash)
| (vertical bar or pipe)
? (question mark)
* (asterisk)
...
...
In comments below you indicate that the code in the question does not reflect your actual problem. Which makes me wonder how you expect us to help. Your real problem is not the error message produced by the specific code, but that your debugging skills are letting you down. Let me try to explain how to debug a problem like this.
First of all, you are passing a file name to LoadFromFile or TFileStream.Create. These calls fail with an error that indicates that the file name is not valid.
So, when faced with that knowledge, the first step is to check the value of the file name that you are passing. Use debugging techniques to do that. Either the IDE debugger, or logging.
Once you have identified what value you are actually passing to these functions you can try to work out what is invalid about it.
To repeat, your real problem is not with the specifics, but in your debugging skills. You should take this as an opportunity to learn more about debugging. Stack Overflow is not a substitute for debugging. Learn to debug better, and your life as a programmer will become very much easier.
I am debugging a DirectShow filter I created with the DSPACK code library using Delphi 6 Pro. When a breakpoint I set is hit in one particular unit named BaseClass.pas, and I begin tracing, the Execution Point jumps to strange places in the source code. This usually indicates that the source code being traced does not match the source code that was compiled into one of the packages being used by the Delphi application. Oddly enough it is only the BaseClass unit since I have traced other units belonging to the DSPACK code library and they do not exhibit this problem. I am not using run-time packages.
I scanned my disk and found only one copy of BaseClass.dcu with a modification date equal to the last time I built the program. I have not modified the source for that unit or any other belonging to DSPACK. Since my Filter is part of the main application this indicates that BaseClass.pas would be subject to a dual use situation since it is used to build the DSPACK component package (dpk), and is also referenced by my main application directly via the TBCSource object my Filter descends from. Note, I did try adding the unit PAS file directly to my Project but that didn't fix anything.
I also went back and re-opened each of the DSPACK package files and did a full re-build. None of this helped. Is there something else I can try to get the source synchronized with the compiled image of the BaseClass unit? Or is a different problem altogether and if so, what is it and how can I fix it?
Sometimes this happens when code is copied/pasted from web pages or other sources, and the lines don't end with CR/LF pairs (#13#10 or 0x0D0A, standard for Windows) but end in only LF (#10 or 0x0A, typically the line ending in *nix systems) or CR (#13 or 0x0D, typical with Mac OSX/iOS). The incorrect line terminators confuse the debugger - this has been an issue for the past several Delphi versions.
You can sometimes fix this by opening the source file using a text editor like Notepad, making a small meaningless change (insert and then delete a blank line, for instance), and then save the file.
I had same problem and made a similar utility. Fixed it.
Basically, just this:
procedure adjustCRLF(filename : String);
var
strList : TStringList;
begin
strList := TStringList.Create;
try
strList.LoadFromFile(filename);
strList.Text := AdjustLineBreaks(strList.Text);
strList.SaveToFile(filename);
finally
strList.Free;
end;
end;
There is another way this can happen: if the IDE erroneously opens another source file with the same name (but different, such as an earlier version) then all the debug points will be incorrect, and the debugger will even allow you to step through the incorrect file.
I've seen Delphi 7 do this once.
Make sure that when you rebuild it, that in the compiler options for your project that you have "Debug Information" turned on. In fact, most of the options under Debugging should be set in your project's Compiler options.
Also, if you haven't already, restart Delphi.
I have the following declaration for DNSServiceRegister:
function DNSServiceRegister
(
var sdRef: TDNSServiceRef;
const flags: TDNSServiceFlags;
const interfaceIndex: uint32_t;
const name: PUTF8String; //* may be NULL */
const regType: PUTF8String;
const domain: PUTF8String; //* may be NULL */
const host: PUTF8String; //* may be NULL */
const port: uint16_t;
const txtLen: uint16_t;
const txtRecord: Pointer; //* may be NULL */
const callBack: TDNSServiceRegisterReply; //* may be NULL */
const context: Pointer //* may be NULL */
): TDNSServiceErrorType; stdcall; external DNSSD_DLL;
In my Bonjour framework I have the following response to an announced service being made active (i.e. to actually start announcing itself, via Bonjour):
procedure TAnnouncedService.Activate;
var
flags: Cardinal;
name: UTF8String;
svc: UTF8String;
pn: PUTF8String;
ps: PUTF8String;
begin
fPreAnnouncedServiceName := ServiceName;
inherited;
if AutoRename then
flags := 0
else
flags := kDNSServiceFlagsNoAutoRename; { - do not auto-rename }
if (ServiceName <> '') then
begin
name := ServiceName;
pn := PUTF8String(name);
end
else
pn := NIL;
svc := ServiceType;
ps := PUTF8String(svc);
CheckAPIResult(DNSServiceRegister(fHandle,
flags,
0 { interfaceID - register on all interfaces },
pn,
ps,
NIL { domain - register in all available },
NIL { hostname - use default },
ReverseBytes(Port),
0 { txtLen },
NIL { txtRecord },
DNSServiceRegisterReply,
self));
TBonjourEventHandler.Create(fHandle);
end;
This is more verbose than I think it strictly needs to be, certainly it was working perfectly well in Delphi 7 in a much less verbose form. I have expanded a lot of operations into explicit steps to facilitate debugging, e.g. to be able to identify any implicit transforms of string payloads that may be occuring "under the hood" in Delphi 2009.
Even in this untidy expanded form this code compiles and works perfectly well in Delphi 7, but if I compile and run with Delphi 2009 I get no announcement of my service.
For example, if I run this code as part of a Delphi 7 application to register a _daap._tcp service (an iTunes shared library) I see it pop-up in a running instance of iTunes. If I recompile the exact same application without modification in Delphi 2009 and run it, I do not see my service appearing in iTunes.
I get the same behaviour when monitoring with the dns-sd command line utility. That is, service code compiled with Delphi 7 behaves as I expect, compiled in Delphi 2009 - nothing.
I am not getting any errors from the Bonjour API - the DNSServiceRegisterReply callback is being called with an ErrorCode of 0 (zero), i.e. success, and if I supply a NIL name parameter with AutoRename specified in the flags then my service is allocated the correct default name. But still the service does not show up in iTunes.
I am at a loss as to what is going on.
As you might be able to tell from the expansion of the code, I have been chasing potential errors being introduced by the Unicode implementation in Delphi 2009, but this seems to be leading me nowhere.
The code was originally developed against version 1.0.3 of the Bonjour API/SDK. I've since updated to 1.0.6 in case that was somehow involved, without any success. afaict 1.0.6 merely added a new function for obtaining "properties", which currently supports only a "DaemonVersion" property for obtaining the Bonjour version - this is working perfectly.
NOTE: I'm aware that the code as it stands is not technically UTF8-safe in Delphi 7 - I have eliminated explicit conversions as far as possible so as to keep things as simple as possible for the automatic conversions that Delphi 2009 applies. My aim now is to get this working in Delphi 2009 then work backward from that solution to hopefully find a compatible approach for earlier versions of Delphi.
NOTE ALSO: I originally also had problems with browsing for advertised services, i.e. identifying an actual iTunes shared library on the network. Those issues were caused by the Unicode handling in Delphi 2009 and have been resolved. My Delphi 2009 code is just as capable of identifying an actual iTunes shared library and querying it's TXT records. It's only this service registration that isn't working.
I must be missing something stupid and obvious.
Does anyone have any ideas?!
UPDATE
Having returned to this problem I have now discovered the following:
If I have a pre-D2009 and a D2009+ IDE open (e.g D2006 and D2010) with the same project loaded into both IDE's concurrently:
Build and run under 2006: It works - my service announcement is picked up by iTunes
Switch to D2010 and run (without building): It does a minimal compile, runs and works.
Do a full build in D2010: It stops working
Switch back to D2006 and run (without building): It doesn't work
Do a full build in D2006: It works again
Does this give anyone any other ideas?
The answer to this is mind boggling. On the one hand I made a completely stupid, very simple mistake, but on the other hand it should never - as far as I can see - have worked in ANY version of Delphi!
The problem was nothing what-so-ever to do with the Unicode/non-unicodeness of any strings, but was actually due to a type mismatch in the PORT parameter.
I was passing in the result of ReverseBytes(Port) - that parameter expected a uint16_t, i.e. a Word value. My Port property was however declared (lazily) as an Integer!!
Once I fixed this and had Port declared as a Word, it now works on both D2007- and D2009+ versions of Delphi.
Very weird.
I can only think that some other edge-case behaviour of the compiler that might have somehow affected this was changed when Unicode support was introduced.
Based on the information that we have available here, the situation is this:
When calling the DLL with your code in Delphi 2007, it gives one result.
When calling the same DLL with your code in Delphi 2009, it gives another result.
The suspicion is, that it is related to the Delphi 2009 compiler.
Logically, the difference must therefore be, that Delphi 2009 sends different values as parameters. In order to make the debugging truly Delphi-independent, you therefore need to create a dummy DLL, which reports the values it gets. Other Delphi-dependent methods may be applied, like looking at the disassembly of the function-call into the DLL, and debugging it so that we know exactly what values are passed, and how, to the DLL, in both compilers.
I can't find the declaration instruction for the vars "ServiceName" and "ServiceType" in your code sample.
Assuming a String type (thus a unicode string), I guess (yes... no D2009 available to test this) lazy typecasting could be an issue:
name := ServiceName;
Why not use the following?
name := PAnsiChar(AnsiString(ServiceName))
Anyhow... just my 2 cts.
BTW:
I always use the pre defined "EmptyStr", "EmptyWideStr" ... so the test would look like:
if (ServiceName <> EmptyStr) then
which should be safe and avoid the confusion of types.
On the other side, Delphi may interpret the '' as an ANSIChar like the following declaration do:
const
MyParagraphChar = '§';
Not sure... I'm confused - should go home now ;)
If the DLL is not written using Delphi 2009, you may want to use something else than PUTF8String. The Delphi 2009 Utf8String type is different from Delphi 2007's UTF8String type.
If the DLL was written using C/C++, I strongly suggest to use PAnsiChar() instead of PUtf8String.
I have a problem with the background compiler in Delphi7: in my project there is a single line of code that causes the background compiler to stop with an error message so that no CodeCompletion is possible. The normal compiler and the syntax check have no problem with this code and the resulting application is correct.
My question is if there is any way to skip this codeline when the background compilation is performed (e.g. compiler directive).
Example code to reproduce the error:
procedure ProduceKibitzError;
var
v : Variant;
begin
v.End; // This line stops kibitz compiler
end;
This code is placed in a unit "Error.pas" which is used in the main unit.
If you try to call CodeCompletion in the main-unit, it stops with the message "Error.pas could not be compiled" (real message is in german).
Interestingly the error only occurs until the project is compiled or syntax check is performed for the first time.
After compilation the CodeCompletion is working and Delphi has to be restarted to reproduce the error.
Update:
Adding an empty Assembler block with an end label is a solution for the problem.
Here is the changed example code that doesn't stop the background compiler:
procedure ProduceKibitzError;
var
v : Variant;
begin
asm
##END:
end;
v.End;
end;
Many thanks,
Christian
The background compiler does not do procedure body analysis when parsing to get to the position of the cursor. Instead, it uses simple syntax matching (such as begin/end pairs). If simple syntax matching indicates that the final end in the unit has been met, then it exits early.
This is what's happening with your example. The first End token is not escaped by the late binding logic because it's not being parsed by the real expression compiler, and instead it's being read as the end of the procedure. The second end looks like the end of the unit, and the background compiler never sees any further.
Added: You might try adding an empty asm/end block to this routine. It prevents the kibitz compiler skipping procedure analysis. Graphics.pas has an asm/end block with an ##end label, and the compiler handles asm/end blocks specially because of it.
Looks like the background compilation doesn't know what to do with the late binding.
Do you know which COM type library is used to make the call on the object? It would benefit both the compilation and the application's performance if you could export and use the pascal-wrapper unit based on the type library. (See Import Type Library option in the main menu)
Try escaping the token with & ?
so
v.&end;