See when Delphi Twebbrowser starts loading a page
The events that you are searching for are OnDownloadBegin and OnDownloadComplete. OnDownloadBegin fires just before the document starts to being downloaded and is therefore the best event for starting of some loading animation. http://docwiki.embarcadero.com/Libraries/XE8/en/SHDocVw.TWebBrowser.OnDownloadBegin OnDownloadComplete fires after the document was downloaded and even if the downloading of the document fails...
How can I make the main form align correctly after my control height is autosized and then I maximize the form?
First, never have a control handle its own event properties. Event properties are for the consumer of the component, not for the developer. The component developer's hook to the OnResize event is the protected Resize method. Override that if you want to know about OnResize-related events. What I suspect is...
Unable to read final few Kb of logical drives on Windows 7 64-bit
Probably, it is a boundary check error. Quote from MSDN (CreateFile, note on opening physical drives and volumes, which you call logical drives): To read or write to the last few sectors of the volume, you must call DeviceIoControl and specify FSCTL_ALLOW_EXTENDED_DASD_IO ...
Opening a project in landscape in iOS doesn't display correctly in Delphi XE8
ios,delphi,firemonkey,delphi-xe8
I am using FXG component ActivityDialog. I used this component in the formCreate method which gave the problem. By removing it from the formCreate and moving it to the formActivate the problem is solved.
Signing certificate error when update apk from XE7 to XE8
can you try Project -> Options -> Provisioning -> New Keystore http://docwiki.embarcadero.com/RADStudio/XE8/en/Creating_a_Keystore_File http://docwiki.embarcadero.com/RADStudio/XE8/en/Create_a_new_Keystore/Alias...
How to call the original class's code when a class helper is in scope?
I think that the only way to achieve this with pure Pascal code is to call Sort from a scope in which your class helper is not active. The point being that if your class helper is active, then Sort refers to the method in the helper. For instance like...
Does “enable runtime themes” affect performance?
What "Enable runtime themes" actually does is telling Windows to Enable Visual Styling of the applications via following manifest entry <dependentAssembly> <assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="*" publicKeyToken="6595b64144ccf1df" language="*" /> </dependentAssembly> You could also have runtime themes enabled in older Delphi versions using different methods. Delphi 7 included TXPManifest component that...
Passing SafeArray from Delphi through to ms-uiautomation libraries
delphi,microsoft-ui-automation
Your GetSelection() implementation is expected to return a SAFEARRAY of IRawElementProviderSimple interface pointers. However, you are creating a SAFEARRAY of VARIANT elements instead, but then populating the elements with TAutomationStringGridItem object pointers. SafeArrayPutElement() requires you to pass it a value that matches the type of the array (which in your...
How can I extract part of a PChar into a string?
string,delphi,optimization,pchar
Let's consider the corner cases. I think they are: AInput invalid. AStart < 1. AStart > FLength. ASubstringLength < 0. ASubstringLength + (AStart-1) > FLength. We can ignore case 1 in my opinion. The onus should be on the caller to provide a valid PChar. Indeed your check that AInput...
How to catch WM_DEVICECHANGE in a control other than TForm?
delphi,delphi-2009,windows-messages
The OS sends wm_DeviceChange messages to all top-level windows. The application's main form is a top-level window, but your control is not, which is why the form receives the messages and your control does not. For arbitrary device types, you have two alternatives: Use AllocateHWnd to create a message-only top-level...
Setting “Server” programatically with a TFDConnection
Please read the documentation, it tells you exactly how to define a FireDAC connection for MySQL: Working with Connections (FireDAC) Connect to MySQL Server (FireDAC) You would specify the DB server as part of a Connection Definition: Defining Connection (FireDAC) Connection Definitions can be defined in an external .ini file,...
Component event detection in Delphi
You can use a virtual method interceptor to intercept the DoAfterOpen virtual call FVirtualIncerceptor := TVirtualMethodInterceptor.Create(TDataSet); FVirtualIncerceptor.OnBefore := procedure(Instance: TObject; Method: TRttiMethod; const Args: TArray<TValue>; out DoInvoke: Boolean; out Result: TValue) begin if Method.Name = 'DoAfterOpen' then ToBeExecutedOnAfterOpen(TDataset(Instance)); end; FVirtualIncerceptor.Proxify(Self.DataSource.DataSet); See this for more info...
Delphi form inheritance, visual bug
It sounds like this is what you have done - let me guess at the steps to reproduce this problem: Created a base regular form - Let's call it TForm1 Added a number of controls to TForm1 Created a second regular form - Let's call it TForm2 You then edited...
Is there any Delphi implementation of MurMurHash3?
I have a murmurhash3 implementation in my FastDefaults unit at https://github.com/JBontes/FastCode Here's the sourcecode for Murmurhash3: {$pointermath on} function MurmurHash3(const [ref] HashData; Len: integer; Seed: integer = 0): integer; const c1 = $CC9E2D51; c2 = $1B873593; r1 = 15; r2 = 13; m = 5; n = $E6546B64; f1 =...
Expression illegal in evaluator
Delphi's operator precedence rules mean that your expression is evaluated like this: if (qryGeneral.fieldbyname('B_PRIJS').IsNull or qryGeneral.fieldbyname('B_PRIJS').Value) = 0 then Put parentheses around your = expression just like you have around you <> expressions, and you should get closer to the results you expect. However, the Value property is a Variant....
Get which capture group matched a result using Delphi's TRegex
Internally Delphi uses class TPerlRegEx and it has such description for GroupCount property: Number of matched groups stored in the Groups array. This number is the number of the highest-numbered capturing group in your regular expression that actually participated in the last match. It may be less than the number...
How to use XPath on TXMLDocument which has namespace prefixes?
Do not try to include namespaces in your XPath query. If all you want is the text of the SomeResult node, then you can use '//SomeResult' as query. For some reason the default xml implementation (msxml) barfs on the default namespace xmlns="http://someurl" on the SomeResponse parentnode. However, using OmniXML as...
Delphi generic frame
procedure TFrameManagement.CreateGenericFrame(ParentPanel: TPanel; FrameName: TFrame); begin genericFrame := FrameName.Create(ParentPanel); genericFrame.Parent := ParentPanel; end; Here FrameName is an instance and you are calling the constructor of that instance. You are not creating a new instance as you intend to do. You need to use meta classes. type TFrameClass = class of...
Can I check data in a 3rd party app with just the handle?
h2 is a window handle, for a window in another process. You can cast it to a TListBox as you did, but that does not make h2 actually be a list box. Hence the runtime error. Essentially you lied to the compiler by claiming that h2 was something that it...
Digital Metaphors Report Builder Surround Group Inside Box
I'm not sure I have understood your question, but try taking a look at using a region, with all members of the group in it, including the lines/shape used, you can then group the items together.
Undeclared identifier in Code Insight?
Looks like some another unit declares TSite type that is used instead; Try declare the var awith the fully qualified name unit main; uses .. lc, ...; var Site: lc.TSite; Also it would make sense to reference the var via FQ-name too, just I ncase some other unit or procedure...
When I load a new image in a TBitmap I must destroy the existing one first?
No. When LoadFromResourceName executes, it clears any memory and resources used by the previous image, and loads the new one. Your code is fine, modulo the missing try/finally. It should be: Bitmap := TBitmap.Create; try .... finally Bitmap.Free; end; Without that, should an exception be raised in between assigning to...
Lazarus/FreePascal, Synapse send file to TCPBlockSocket
delphi,freepascal,lazarus,netcat,synapse
Well... Hex 00 00 B5 6C (your extra bytes in reverse) is equal to 46444. So my guess is that TFileStream or SendStream sends the number of bytes it wants to send before the actual data. Looking at the code of Synapse there is the function: procedure TBlockSocket.InternalSendStream(const Stream: TStream;...
How to open and read “/proc/cpuinfo” on Android device in Delphi
The answer is simple (tested): var FS: TFileStream; ch: Char; RawLine: System.UnicodeString; begin if FileExists('/proc/cpuinfo') then begin try RawLine:= ''; ch := #0; FS:= TFileStream.Create('/proc/cpuinfo', fmOpenRead); while (FS.Read( ch, 1) = 1) and (ch <> #13) do begin RawLine := RawLine + ch end; Memo1.Lines.Append(RawLine); finally FS.Free; end; end; end;...
Remove specific XML element in Delphi
You can use the IXMLNodeList.Delete() or IXMLNodeList.Remove() method to remove nodes: var Root: IXMLNode; begin Root := XMLDocument1.DocumentElement; Root.ChildNodes.Delete('ElementData'); for I := 0 to Root.ChildNodes.Count-1 do Root.ChildNodes[I].ChildNodes.Delete('ElementData'); end; var Root, Child, Node: IXMLNode; begin Root := XMLDocument1.DocumentElement; Node := Root.ChildNodes.FindNode('ElementData'); if Node <> nil then Root.ChildNodes.Remove(Node); for I := 0...
Firemonkey ListView item indexes not updating
While the real fix is in Embarcadero's ball court, this seems to be the only work-around: procedure ReindexListView(AListView: TListView); var X: Integer; begin for X := 0 to AListView.Items.Count-1 do AListView.Items[X].Index; end; Behind the scenes, there is a known bug in the generic TList implementation, specifically a mis-hap with the...
How to add new online ressources to RAD Studio help system
After talking to somebody formerly on the development team of MS Document Explorer and now r2reg, this is not possible. And since MS moved on from MS Help 2 and now uses MS Help Viewer, there will not be any further development to allow for this.
Missing operator or semicolon in Delphi 7
Label6.Caption('rok') Caption is a property which behaves as a variable does. You treat it as though it is a procedure (which it is not) and hence the compilation error. The parser knows that the only thing that can follow a property name is a semicolon, bracket (if the property is...
What is required in Delphi 2007 to use Variant arrays?
delphi,com,delphi-2007,variant
The code is missing a unit from the uses clause. That unit is named Variants and contains all the symbols that the compiler cannot find. Add that unit and the code will compile.
Set node state in a virtual tree
You could write Node.States := [vsDisabled];, to make your code compilable. But this is not what you are supposed to do. There are node states that you must keep untouched and by the mentioned statement you would throw them away and set only the vsDisabled one. You wanted to write...
Why does my application using OmniThreadLibrary Parallel.Pipeline continue remain running in the background after being closed?
multithreading,delphi,delphi-xe7,omnithreadlibrary
You should call FPipeline.input.CompleteAdding from TEmailQueue.Destroy. Otherwise, SendEmailStage will never stop.
Delphi Bug in Indy FTP List method?
This is not a bug in TIdFTP. It is more an omission in the Indy documentation. EIdReplyRFCError means the FTP server itself is reporting an error in response to the command that TIdFTP.List() is sending. Depending on the values of the ADetails parameter and TIdFTP's UseMLIS+CanUseMLS properties, List() can send...
How cand I include a bitmap in my custom component (if is possible)?
Change BMP to BITMAP in your RC file, and change HInstance to FindClassHInstance() in your code: FIXED BITMAP "fixed.bmp" Glyph.LoadFromResourceName(FindClassHInstance(MyComponent), 'FIXED'); ...
Get list of process
This is very platform-specific, and as such there is nothing in FireMonkey or VCL to help you with it. You have to use platform APIs directly. For instance, on Windows you can use CreateToolhelp32Snapshot(), Process32First() and Process32Next(): Taking a Snapshot and Viewing Processes Or you can use EnumProcesses(): Enumerating All...
Can I compare Real48 using generics.defaults?
This defect is present in all versions of the compiler. Since Real48 was deprecated more than a decade ago I would expect that Embarcadero would not change the behaviour, even if you submitted a bug report. Of course, you should still submit a bug report, but I would not hold...
Delphi, Lazarus - Listbox out of bound (0) TString
delphi,listbox,indexoutofboundsexception,lazarus,tstringlist
The error is telling you that the list box selectedbox is empty. I would expect that the error is more like this: List index out of bounds (0) That tells you that index 0 is invalid which can only mean that there are no items in the list box. Presumably...
FastReport Master/Detail in Delphi XE2
When creating the preview FastReport does something like this code: while not MasterBand.DataSet.Eof do begin ...Do special FastReport's work :) while not DetailBand.DataSet.eof do begin ...Do special FastReport's work :) DetailBand.DataSet.Next; end; MasterBand.DataSet.Next; end; In your code: while not opr_operatorcount_ods.Eof do begin frxReport1.PrepareReport(false); opr_operatorcount_ods.Next; <-- here opr_operatorcount_ods is in the...
How can I send data between 2 applications using SendMessage?
As noted in comments, you must use SendMessage with WM_COPYDATA. The primary reason for this is that the message sender is responsible for cleaning up the resources used for the transfer. As noted in the documentation : The receiving application should consider the data read-only. The lParam parameter is valid...
unelevated program starts an elevated updater, updater should wait for finishing of program
delphi,handle,createprocess,waitforsingleobject,shellexecuteex
Your code is not working because the handle table is per process, which means that the second process could have the same handle pointing to another kernel object. Below, there is one of many possible solutions: When creating the process 2, pass the PID of the process 1 as parameter:...
Can I pass type parameters to a testcase in DUnitx?
unit-testing,delphi,generics,dunitx
Try to make your test class generic and register your test class with every single concrete type you want to test. [TestFixture] TMyTestObject<T> = class(TObject) public // Sample Methods // Simple single Test [Test] procedure Test1; // Test with TestCase Atribute to supply parameters. [Test] [TestCase('TestA','1,2')] [TestCase('TestB','3,4')] procedure Test2(const AValue1...
How to remove duplicates in ListBox?
delphi,listbox,duplicate-removal
Try NoDuplicate.CaseSensitive := True; ...
SetProcessWorkingSetSize does not work in compiling 64bit
The documentation tells you to pass high(SIZE_T). You do this when compiling for 32 bit, but not for 64 bit. This is what you mean to write: SetProcessWorkingSetSize(MainHandle, high(SIZE_T), high(SIZE_T)); Do note though that this code won't help performance on your machine. In fact, the only thing it can do...
Can I specify the save location for Delphi .dsk file?
The IDE places the file in the root directory of the project. You cannot influence it to do otherwise.
Unable to use apostrophes in a string
My pshychic debugging tells me that you are looking at the string in the debugger. The single quote is the string delimiter. So it needs to be escaped. It is escaped by doubling it. So when the debugger shows a string like this: 'a''b' that is actually three characters long,...
PasswordChar in Delphi XE8's TMemo
The VCL memo control is a loose wrapper around the Win32 multiline edit. The password character functionality of the edit control is only available for single line edits. The behaviour is controlled by the ES_PASSWORD style for which the documentation says: Displays an asterisk (*) for each character typed into...
IP*Works! SearchMailbox for IMAPS returns all available emails, even unmatching
Thanks to the answer of @arnt, I figured out a solution that works for me. Yes, for every Message that corresponds to the search criteria, the event OnMessageInfo is fired. Since I need to go through all messages in a loop, I ended up doing this: procedure TReadIMapObjectsFavFktProperty.MessageInfo(Sender: TObject; const...
connection refused when I try to connect client with server
You should go to router admin console, find something like "port forwarding" and route the port (8081) to your computer IP - you have to say the router that traffic on this port should go to your computer
Delphi 7 - Save to a Specific .INI Files Name
When you open an ini file, store the filename in a variable as explained in many comments. Example, (FCurrentIniFilename: String; is a private variable in TForm1): In the FormCreate event: FCurrentIniFilename := ExtractFilePath(Application.EXEName)+ 'A.ini'; Read := TINIFile.Create(FCurrentIniFilename); ... In the OpenFile event: if OpenDialog.Execute then begin FCurrentIniFilename := OpenDialog.Filename; Open...
Function that returns intersection of two TShapes, including TPaths?
There is no built-in function for this. But what I think you are trying to do is this: Given a polygon (aka TPath) made up for distinct points connected by lines. Return all points in ShapeA that lay inside ShapeB. Point intersection This can be done using PointInObjectLocal. Run a...
Is it a bug that attempts to compile this code results in IDE terminating or the compiler failing to run?
This is certainly a bug. It occurs in all the IDE versions that I tested, XE3, XE7 and XE8. I honestly don't think there's a lot you can do. For me the IDE terminates on compilation every time. I think you'll just have to write the code in a way...
'Session Ended' when lauching app from Delphi to iOS Simulator
delphi,ios-simulator,delphi-xe7,paserver
After a few days, I found out what the problem was, so I'll post the solution here to help others who might have the same problem. Go to Project --> Project Options --> Version Info Under de iOS Simulator configuration, Delphi IDE (XE7) automatically inserted the following key and value:...
Referring to interface versus to an object implemeting it?
The difference is explained in the documentation: When TXMLDocument is created without an Owner, it behaves like an interfaced object. That is, when all references to its interface are released, the TXMLDocument instance is automatically freed. When TXMLDocument is created with an Owner, however, it behaves like any other component,...
HasValidFileNameChars fails for UNC files
The function behaves correctly because a \ is not a valid character for a file name. It is the path separator. The distinction here is between file names and paths. Using your example, \\ETA-PC\tests\test.ini is a path, but the file name is test.ini. I suspect that you are looking for...
Delphi - extract string between tags (duplicate tags)
Function sExtractBetweenTagsB(Const s, LastTag, FirstTag: string): string; var pLast,pFirst,pNextFirst : Integer; begin pFirst := Pos(FirstTag,s); pLast := Pos(LastTag,s); while (pLast > 0) and (pFirst > 0) do begin if (pFirst > pLast) then // Find next LastTag pLast := PosEx(LastTag,s,pLast+Length(LastTag)) else begin pNextFirst := PosEx(FirstTag,s,pFirst+Length(FirstTag)); if (pNextFirst = 0) or...
How to correctly have modeless form appear in taskbar
windows,delphi,windows-7,delphi-xe6,windows-95
It seems to me that the fundamental problem is that your main form is, in the eyes of the VCL, not your main form. Once you fix that, all the problems go away. You should: Call Application.CreateForm exactly once, for the real main form. That is a good rule to...
What is the different between “Console target” and “GUI target” in DCC32 option?
These options control the subsystem of the output file. They only have meaning on Windows. They are equivalent to the $APPTYPE directive. The $APPTYPE directive controls whether to generate a Win32 console or graphical user interface application. In the {$APPTYPE GUI} state, the compiler generates a graphical user interface application....
Why Application.OnException never runs?
delphi,exception-handling,delphi-xe2,delphi-7
The only rational explanation is the FormCreate is not executing. You need to assign it to the form's OnCreate event handler. Use the object inspector to do so.
Open file manage and get selected file
You can use JFileDialog Check the below link http://bluexmas.tistory.com/427...
What would the design look like for a class that implements a threaded email sending queue?
multithreading,delphi,delphi-xe7,omnithreadlibrary
I suggest you to set up OTL. You would most probably have the only SMTP server, so the only mail-sending thread, in case you would later add more notification sending servers ( like sending SMSes to different phone operators ) - you would add more outgoing "sink" threads. Personally I...
Delphi - Use a string variable's name in assignfile()
Is it possible to use a variable in the AssignFile command? Yes. The second parameter of AssignFile has type string. The expression cFileDir + '\' + sFile has type string. FWIW, AssignFile is known as a function rather than a command. Getting on top of terminology like this will...
Delphi and sleep function
First off, WinExec() has been deprecated since 32bit Windows was first introduced. Use ShellExecuteEx() or CreateProcess() instead. This also provides you with a process handle that you can use to detect when the spawned process terminates, and you can also use it to kill the process if your timeout elapses....
how to connect to a NIC card or network adapter knowing its IP address?
delphi,network-programming,ip-address,windows-10
It sounds as though the library that you use requires elevated rights. Nothing significant has changed in Windows 10 regarding UAC. If your program is running elevated it will succeed. It fails when it is not elevated. So your problem would appear to be that you are failing to execute...
Delphi passing Types in parameters
What you are asking for can be done by either: deriving the various Form classes from a common base class that exposes the field you want to access: procedure A(aForm : TBaseForm); begin ShowMessage(aForm.edtUser.Text); end; type TBaseForm = class(TForm) edtUser: TEdit; ... end; TDerivedForm = class(TBaseForm) ... end; ... frm...
Issues with AES Encryption using SynCrypto
delphi,encryption,cryptography,aes
AES is a block cipher algorithm. It means that it works by blocks that are 16 bytes in size for AES. So you need to use padding if your data does not fit in 16 bytes blocks (which is the case for your text). Instead of trying to re-invent the...
Custom component controls keep re-creating
You need to set the stored property of your sub components to false. paLaterale := TPanel.Create(Self); paLaterale.Stored := false; etc ...
Reduce lines, use case?
Just a simple way to improve the code: var ix: Integer; ... ix := StrToInt(valmes.Text); WebTesta.OleObject.Document.all.Item('expmonth', 0).value := IntToStr(ix-1); You can add some sanity checks using if TryStrToInt(valmes.Text,ix) then .......
Why can't I use compiler intrinsics in an asm block?
You cannot use compiler intrinsics because they are processed by the Delphi compiler rather than the assembler. Intrinsics are resolved by the Pascal compiler processing and parsing Pascal expressions, and then emitting code. That's the job of a compiler rather than an assembler. At least, that's my mental model. In...
How to make TDBCheckBox update its DataField immediately after click?
delphi,checkbox,event-handling,delphi-xe3,data-aware
A couple of problems with using the DataChange event to do things like this are that It's called a lot more frequently than you actually need, to react to your DBCheckBox being clicked and Doing a .Post to the dataset is going to change its state, which is generally a...
Loop through records on a cxgrid and update a field/column
What your updated q is asking for is straightforward and as usual with Devex stuff, it's all in the OLH as long as you can find your way into it. A way to find which rows currently match the filter is to use the cxGrid1DBTableView1.DataController.FilteredRecordIndex[] property. You can then find...
How can I convert PNG to GIF keeping the transparency?
It is possible to transfer an image from a PNG to a GIF. However, I don't recommend that you do so. The GIF format is substantially less capable than PNG. PNG supports RGBA color channels and partial transparency. GIF uses a 256 color palette and no support for partial transparency....
Odd compilation error message
This is the declaration of the InsertRecord method: procedure InsertRecord(const Values: array of const); The parameter is a variant open array. Variant open array parameters are implemented internally by being passed as TVarRec instances. And TVarRec cannot contain records. Since TGUID is a record, it cannot be passed in a...
Delphi - converting string back from UTF-8
value = '散汤湡獤杀潯汧浥楡潣m䌴䅓㜭䙇ⵊ䵙㑗㈭呖ⵆ䥉儵䈭呎́'#4 This is indicative of you interpreting 8 bit text, presumably UTF-8 encoded, as if it were UTF-16 encoded. As a broad rule, when you see a UTF-16 string with Chinese characters, either it is a correctly interpreted Chinese text, or it is mis-interpreted 8 bit text....
Call Delphi XE6 unicode dll from C# asp.net
BadImageFormatException typically indicates a bitness mismatch. Your Delphi module is 64 bit and the C# module is 32 bit, or vice versa. You have other problems. At least the following: You cast a UTF-16 UnicodeString string to PAnsiChar. That cast is not correct. You return a the address of a...
How to get enabled property of a control?
If you have the window handle for a control, then the IsWindowEnabled function will tell you whether it is enabled. Keep in mind that that is acting on the window at the API level, not the Delphi VCL level. In Delphi, there can be controls that do not have window...
Preventing component creation - Delphi
If you include components in the designer, then they will be created when the form is created. Nothing you can do to stop that. The logical conclusion is that you need to create the components at run time. One obvious way to make that easier is to put the components...
Strings getting corrupted in ComboBox.AddObject. How to add them the proper way?
There's nothing to keep the string alive. When you write: s := PChar(sl.Values[sl.Names[c]]); an implicit local variable of type string is created to hold whatever sl.Values[sl.Names[c]] evaluates to. That local variable goes out of scope, as far as the compiler is aware, nothing references it, and the string object is...
AES encryption differences between php mcrypt and a Delphi component
MCrypt expects the key to be a binary string, but you pass a hex encoded string into it. Use $key = hex2bin($key); or $key = pack('H*', $key); depending on PHP support. This must be done before calling mcrypt_encrypt(). Security: Don't ever use ECB mode. It's not semantically secure. There is...
Delphi XE4 - TImage is not displayed at runtime
Your version of SynGdiPlus is clearly deprecated. The current revision has a NOTSYNPICTUREREGISTER condition, which is enabled by default: initialization {$ifndef NOTSYNPICTUREREGISTER} Gdip.RegisterPictures; // will initialize the Gdip library if necessary {$endif} Ensure you got the latest revision of the source code tree....
Flush file buffers in on non-Windows platforms
The RTL has no function for flushing a file without closing it. You have to use platform-specific functions instead. On Windows, TFileStream uses the Win32 CreateFile() function to open/create a file, so you can use FlushFileBuffers() to flush it. On other platforms, TFileStream uses the POSIX open() function to open/create...
Need help to find FireMonkey equivalent of the VCL TpaintBox.Canvas.Handle in the context of building graph
In VCL, TPaintBox is a TGraphicControl descendant that draws onto the HDC of its Parent control's HWND. When the Parent control receives a WM_PAINT message, it draws itself onto the provided HDC as needed, and then temporarily gives that same HDC to each child TGraphicControl when drawing them, clipping the...
How do we improve a MongoDB MapReduce function that takes too long to retrieve data and gives out of memory errors?
performance,mongodb,delphi,mapreduce
Phew what a question! First up: I'm not an expert at MongoDB. I wrote TMongoWire as a way to get to know MongoDB a little. Also I really (really) dislike when wrappers have a plethora of overloads to do the same thing but for all kinds of specific types. A...
How to use TThread.Synchronize() to retrieve the text of a TEdit control?
First, declare a method in your form that retrieves the text. This method can be called both from the main thread and a worker thread: Type TMyGetTextProc = procedure(var s: String) of object; procedure TForm1.GetMyText(var myText: String); begin TThread.Synchronize(nil, procedure begin myText := ATedit.Text; end ); end; Secondly, when you...
Delphi XE8: problems running an external console application, waiting for its results and capturing its results
delphi,pipe,console-application,createprocess,waitforsingleobject
To summarize: @David Heffernan's code in Execute DOS program and get output dynamically works. The problem is that the console application emits UTF-16.
Saving Excel workbook as PDF gives me an OLE error 800A03EC
I don´t think that converting to PDF would be a normal SaveAs. You should try exporting it, as said here
How to execute a file with a different extension's associated application?
delphi,winapi,shellexecute,file-association
Call ShellExecuteEx and specify the lpClass member of the SHELLEXECUTEINFO struct. Note that you must include SEE_MASK_CLASSNAME in the fMask member. For instance, set lpClass to '.txt' to request that the file be opened with the program associated with the .txt extension. ...
Infinite loop in parsing a string using pointer math
delphi,pointer-arithmetic,delphi-xe8
Your loop runs forever because P will never be nil to begin with, not because of an issue with your pointer math (although I will get to that further below). PChar() will always return a non-nil pointer. If S is not empty, PChar() returns a pointer to the first Char,...
Asynchronous TADOQuery's OnFetchComplete not synchonized to main thread
delphi,asynchronous,delphi-xe4,delphi-xe8,tadoquery
In my experience the easier way is to use either: Synchronize or TThread.Queue This is not a bug or at least not a VCL bug. This behavior is handled by the provider and we cannot say it is not following the specification because there is no specification about how to...
Currency Formatting with Delphi
Make sure the MaxLength of edtZaklad is 0. var Form21: TForm21; Check:string; //to break the loop. function GetCurrency(Num: String):string; var i: Integer ; Str:String; zaklad: Currency; begin Result := ''; for i := 1 to length(Num) do begin if (Num[i] in ['0'..'9']) then Begin Str := Str + Num[i] ;...
It is required to free the IShellFolder interface returned by SHGetDesktopFolder ? and how?
COM interfaces are reference counted, and the Delphi compiler generates code to automatically manage the reference counting for you. Each time an interface variable is assigned, Release is called if the variable is not nil, and AddRef is called if the new value is not nil. When the variable goes...
How to make my custom control be notified when his form or application receives and loses focus?
I want to suspend some updates of the control when his form is not active and resume the updates when the form is activated. If those updates are done continuously, or are being triggered by a timer or actions, then you could be done with: type TMyControl = class(TControl)...
How to add menu items separators programmatically on Windows?
windows,delphi,drop-down-menu,menuitem
Create a new menu item and set its caption to '-'. var MenuItem: TMenuItem; .... MenuItem := TMenuItem.Create(Menu); // Menu is the menu into which you are adding MenuItem.Caption := '-'; Menu.Items.Add(MenuItem); Instead of Add, which adds to the end of the menu, you can use Insert to insert the...
Delphi Access Violation when moving button on form
delphi,button,access-violation
I am executing the procedure with CreateThread(). That is your problem. VCL code must only be called from the main UI thread. Use TThread.Synchronize to invoke the VCL code on the main thread. That said, a timer might be a more appropriate solution to you problem than a thread....
do oncalculate fields in one table using values from another table
You are not telling us what data access component you are using. The recommended way to do this is using a Query component (TSQLQuery, TADOQuery, TIBQuery,...) , then have the SQL for that query retrieve all necessary information. All the fields that you want access to in you OnCalcFields() should...