In delphi, creating ActiveX controls was something that was once more popular than it is now. However it remains possible to create ActiveX controls with Delphi. This question assumes Delphi 2007, but it should be the same no matter what Delphi version you use.
There are some strange errors in Delphi when you create ActiveX controls. IN my case, I can
now no longer import a certain class that I am trying to import and wrap, and Delphi won't tell me why any more, just that it could not load the unit "symbol information".
In this case, I am wrapping an open source control, and my first few attempts to wrap it worked fine, but I found that I had to redo the import once I found properties that were written in a way that the ActiveX wrappers were missed. It's easier to regenerate an ActiveX wrapper than to fix it by hand. Until you get stopped cold like this:
Error
Could not load unit [unit] symbol information for [TClassName].
Do you want to try to find this file yourself?
If I click Yes, I get a browse (file open) dialog and it has the file filter set to "DCU". Which means, it wants me to find the DCU file for this unit. If I browse to it, or if I don't, the results are the same. No amount of recompiling will clear this error condition.
does anyone know what this error really means, and better yet, how to fix it? Googling this particular error message shows it comes up in forums other than English, but is so obscure nobody has yet documented it.
There is an issue with the Library Path in Delphi, that for the ActiveX Control wizard to work properly, all sources needed for the parser to parse the unit in question must be in the library path. Since the ActiveX control wizard functions outside your project, your project search paths are NOT included in the list of folders that are used to parse the sources of the VCL control that is to be wrapped and turned into an ActiveX Control.
Solution:
Fix the library path.
Related
I have deveoped a custom file type, together with a custom editor (basically a tree with several data pages attached and a few extra buttons). OK, I can run it stand alone and that is fine, and even add it to the tools menu, but I would like to integrate it into the Delphi IDE so that my custom editor (or a similar new version) appears in the IDE, rather like a DFM file has a custom editor. I can find references to most extensions in the Delphi IDE, but not this one. Any guiding hands? Note that this is not a property or component editor (the file type has nothing to do with either of these) nor is it simply syntax highlighting of a text file.
AFAIK it currently isn't possible to reliably integrate a custom editor into the Delphi IDE. The required API simply isn't there. See QC89028 Custom Module support.
During the Delphi 2010 and XE betas I spent most my spare time trying to get a resource editor integrated. Although the effort had the official blessing of Embarcadero and got some, half hearted, support from the IDE engineer, I was never able to get them to deliver on their promises and surface the module API. I eventually abandoned the project.
Update: I've now checked my old correspondence regarding this and it turns out part of the problem was that IOTAModuleCreator (used to implement File|New for custom file types) and IOTAEditorContent (used to transfer data to/from the custom module) only supports text data. Binary data gets mangled.
You can probably do this via an IDE plugin that uses the ToolsAPI (see ToolsAPI.pas in the IDE's source folder (e.g. Program Files (x86)\Embarcadero\Studio\source\ToolsAPI\ToolsAPI.pas.)
For information on writing a plugin in general, see David G Hoyle's excellent blog. Once you know the basics - i.e., write a 'wizard' and get it to do something - you will need to work on integrating your editor.
I have never done this, and so I can't guarantee it is possible. However, some interfaces that look worth investigating and implementing are INTACustomEditorView, which represents a 'view' (file tab when that file is open - think the code editor, Welcome view, type library editor, etc) and IOTAEditorViewServices, to register your custom view. I do not know how you associate a view type with a file type, sorry - possibly something to do with the personality interfaces. You might also be interested in INTACustomEditorSubView which is what creates a tab on the bottom of a file.
Good luck, and if you find a solution please write here so that other people can learn too!
How can i fix this error and from where I get dxDBGrid file,i'm a new in Delphi,i'm getting the: [Fatal Error] File not found: 'dxDBGrid.dcu'
As others have already told you, that's the file that contains Developer Express's TdxDBGrid. It's quite an expensive product, so before you go off and purchase it, it would be wise to see if you actually need it (I'll explain why I have a hunch you might not in a moment).
First thing to do is do a Find in Files search through all the units in your project, to see which of them lists dxDBGrid in the Uses list in its Interface section. Once you've found the file try and open it and see if the form contains a component of type TdxDBGrid. If it doesn't, remove dxDBGrid from the unit's uses list and try recompiling.
The error may go away, in which case, problem solved. The reason I think the error might go away is that typically, using a TdxDBGrid on a form causes a lot of other units from the DevEx package to be added to the unit, in addition to dxDBGrid, and usually they would appear in the unit's Uses list ahead of dxDBGrid, so if Delphi really can't find the files of the DevEx library, it's surprising Delphi isn't complaining about not being able to find those before it gets to dxDBGrid. So if it uses dxDBGrid alone of the Devex package (other units in their package typically begin with dx or cx), it's possibly only there is a historical hangover. Otoh, if the unit does use other dxXXX or cxXXX units and Delphi isn't complaining about not being able to find their DCU files, it must be finding them (in .DCU or .PAS form) ok.
If you're still stuck, post the Interface section of the unit which provokes the compiler error you described.
My system configurations are a follows Delphi2010 on windows 7 professional. I have a problem with some of .dfm files in the project.
I got it as follows. First of all I needed to change some datatypes of TOraQuery component fields from TStringField to TWideStringField and I started it doing manually like opening .dfm change one by one (Find-Replace) everything was fine later on because our project is huge I decided to change everything at once so by using Notepad++ editor and by using option Find in Files and replace all I did replacement. So after this operation I started getting this error like 'TWideStringF class not found' when I wanted to open particular .dfm file. I cannot open this .dfm files even if I press ignore.
PS: Even when I try to open files that has errors in Notepad++ editor to get the line TWideStringF I cannot find it.
How to solve this problem ?
Can anyone give me a clue ?
thank you.
Try finding the "TWideStringF" in ALL your source code first to know where the problem is comming, after that, well, all dependes on what you find!
The Delphi IDE need to be able to find the classes specified in the DFM. It creates instance of these on the design surface for you to interact with.
Editing a DFM by hand is a common practice. I do it often, as sometimes it is faster than any other method. However, it comes with a problem if the class or property can not be found it can cause the DFM not to load. So extra care must be taken to insure that manual edits done correctly.
In this case you can restore the file, and redo the search and replace, or to look at the instances where it's broken and fix them all by hand.
Search for: TWideStringF I suspect you will find that is missing the remaining ield required. Note: Searching in IDE will not work as it won't search DFM files.
We are trying to split up our monolithic EXE into a combination of an EXE and several packages. So far, we have one package that we're trying to use, and when running the EXE Codeguard shows the following error on startup:
CG Error
Two different CRTLDLLs are loaded. CG might report false errors
(C:\Windows\system32\CC32100MT.DLL)
(D:\Projects\Foo\Bar.bpl)
OK
I read this as two different runtime libraries being loaded - one, the correct one (CC32100MT.dll), one incorrect, which is the package we're trying to use.
Continuing to run the program shows odd errors, especially casting between classes or passing a pointer to a class as a parameter in a method that crosses the EXE/DLL boundary. Codeguard itself doesn't show any other errors at all though. Edit: This is now resolved, and wasn't related. The program appears to run correctly, but the warning Codeguard shows is still worrying.
How do we solve this?
Some more details
We've looked at as many things as we (the developer working on this and I) can collectively think of:
Each project is built using runtime packages. The EXE host lists Bar in its package list.
Each project is set to compile with dynamic RTL. However, changing this does not solve the problem.
The package is linked to the EXE via its BPI file, but linking via a LIB makes no difference either.
The EXE and BPL are compiled with the same project settings, where the same options exist for both types of project. We think, anyway :)
There is only one copy of the BPL and BPI on the system: it's definitely linking to the right one.
Examining the EXE and BPL with Depends and TDump show they are both using C:\Windows\system32\CC32100MT.DLL. They should both be using the one RTL.
Creating a new project (a plain VCL forms application) and linking to the BPL (via its BPI) works fine. Something in the process of adding all the files and LIBs that make our EXE contain the code it needs to changes this, but we haven't been able to figure out what.
The LIBs all either correspond to DLLs we use (flat C interface, usually look as though they were built with MSVC) or are simple projects with lots of related files, compiled to a lib for the purpose of linking into the EXE - these correspond roughly to the areas of the program we want to split to BPLs, by the way. There don't seem to be project options for the LIB projects that would affect RTL linking, unless we've missed them.
I have exhaustively hunted through Depends and looked at all RTL and CC32*.dll files the EXE and every single DLL references. All are identical: rtl140.bpl and CC32100MT.DLL. Fully qualified paths show they are the same files, too. Everything should be using the one same run-time library.
Edit: The final EXE is complex, built with several libs, several DLLs, etc. All these, when built with C++Builder, are built with the current version. Is it possible there's something in one of these DLLs or LIBs that could cause a problem? I don't know enough about how the RTL is linked in to be sure about where to look... my (naive?) assumption is that the linker would normally link in one set of RTL functions, but that of course doesn't seem to be happening... and I don't know how things change when using packages. Is it possible this error has always existed and Codeguard has not flagged it before, because we haven't used something dynamic like a package?
Perhaps another question is, Why would a package have its own RTL anyway, or what would make it count as 'a RTL DLL' to Codeguard?
We're stumped. Absolutely stumped. We've had other problems using BPLs (they seem to be surprisingly tricky things, especially using C++) but have managed to solve them all. This one we've had no luck at all and we'd really appreciate any insights :)
We're using C++Builder 2010 (as part of RAD Studio actually, but with little Delphi code apart from components.)
Edit: Started a bounty. I'd really like to solve this!
Edit 2: Thanks to David Dean for his help (marked as answered below.) Via email, he pointed out this issue was reproduced in a simple test case by someone else, and is logged in Embarcadero QC as report 86335. Currently there is no fix, but the warning does not appear to indicate a genuine problem (ie, it's probably a spurious error, and while it's a pity to have to click past the dialog when you run, hopefully there's nothing in the error to worry about.)
Since one of these is coming from a .bpl, did you try turning off "Build with runtime packages" in the project options?
We had a similar problem. We tracked it down to a (non VCL) .cbproj that was created without the "Multithreaded" option.
As far as I can tell, the only time you get chance to set this option is when you create a new .cbproj, it cannot be changed afterwards using the GUI. We ended up "hacking" the .cbproj to include the following:
<Multithreaded>true</Multithreaded>
To determine which dll is causing the issue, it should be the last dll loaded in the output window just before you see the CG message.
Did you check if you use _TCHAR as char. We had some similar problems with RAD Studio and we found a workaround using _TCHAR as char. As soon as one DLL or BPL Project is compiled with wchar_t, this code guard error appears.
We also figured out, that EXE projects can be compiled with TCHAR = wchar_t without any problem (the main function will be WIDE).
The settings does not affect the GUI being able to handle UNICODE.
A customer logged a similar case in our public bug tracking system and the bug has been identified and fixed in the latest release.
We have a Delphi 5 application, that is built without runtime packages, dlls or external resources (i.e. a single executable). when we install it on a clients PC we get the following error messages:
Class TListView not found
or
Class TImage not found
We have installed it on dozens of PCs before without incident, but this latest install is problematic.
The target PC is a fresh install of Windows XP (Service pack 3) with no other software installed.
It does not complain about all of the classes however just one or two. for example TPanel/ TForm/ TEdit are all OK.
Can anyone think what is causing this?
EDIT
The exe on the new PC is on 30 or so other PCs that I know of, ranging from windows XP Sp1,2,3, Windows Vista and Windows embedded. both old and new PCs were installed with an old version and then updated with the newest version. The only difference is that the version jump was higher for the latest install.
This is typically an error during the streaming of a .DFM. Usually this error occurs with TLabel components because many folks remove the TLabel fields from the form or frame in order to cut down on the clutter and reduce the instance size of the form. The common and confusing mistake they make, however, is that in their over-zealousness, they remove all TLabel references. That is when bad things start to happen. Let me run down how the streaming system locates a component's class.
Remember that the class reference in the .DFM is just a string. The streaming system has to convert this string into a class reference (TComponentClass). There are two mechanisms that the streaming system uses to do this. The first one is very simple and involves a global list of class references. You can call RegisterClass or RegisterClasses to explicitly make the streaming system aware of it. The second is much more subtle and not very well known; in fact it is all part of the "magic" of Delphi :-). When the compiler builds the form, all the fields that represent the components on the form are processed and an internal table is built as part of the RTTI or metadata for the form/frame/datamodule itself. This table contains a list of references to all the individual component types represented by the component fields. So even if a component is not in the global list, it can still be found by scanning through this compiler generated table. That is what the Classes.TReader.GetFieldClass() method does.
Back to my TLabel example, this problem is easily fixed by simply ensuring that at least one of a given component type has a field. So as long as there is at least field of type TLabel, all the other TLabels will load just fine. So in your case, make sure the TListView or TImage fields haven't been deleted.
Re0sless,
I suggest you open and close every form of your application and do a fresh build after that. If memory serves me well, that was the solution when we encountered similar problems.
You might also take a look at DFM Check to open and close all your dfm's automatically and at CnPack to help you clean your uses clause.
Regards,
Lieven
I think Lieven is definitely on the right track: simple base classes not being found during runtime are a Delphi (linker) problem. This exception is not caused by the Operating System.
My experience with similar problems: the linker generates a project with the units wrongly arranged.
Example: a form unit is linked in before the base units. Forcing the project to completely recompile/relink itself should make this exception go away.
A simple [Rebuild All] will probably not suffice. You might try to recompile without optimizations.
I have tried to reproduce this error but I have not been able to. The Delphi compiler/linker is one of the best - speed of compilation/speed of compiled exes - but this bug is definitely a show stopper.
Note: I have only experienced
this error in D5. Has anybody else
experienced this error with other
Delphi versions?
I had the same problem. Class TCheckBox not found. I usually edit large set of components through .DFM of form(for example renaming large amount of component). This error comes when I rename all CheckBox on my form through it .DFM.
I just cut all the checkbox and paste them again(So .DFM file is refreshed). The error disappeared.
I've seen a similar problem due to a file copy error. To make matters more confusing, the fault was on an intermediate media device. The issue was resolved by simply recopying the file from the existing release build.
It is probably impossible to confirm now, but it is quite possible that the problem was 'solved'; not because of the removal of an unnecessay uses clause item, but because it also involved a new copy of the executable.
The solution for all errors of this type "Class XXX not found" is simple. Open DFM file of a form in text editor and manualy remove the definition of the XXX object in it.
Change the name of the Form and save the .pas with other name. Change all references to create the new unit name if this is used in other units. Build All.
With this the error disappeared.