CPort not work properly with windows 10 - delphi

RESOLVED
Just update Windows 10 and the problem disappears
I have an old program developed with Delphi 7 and uses TComPort for serial communication.
On windows 10 TComPort wrong to enumerate the ports, it does not return the port number.
The program works perfectly from windows xp to windows 8.1 u1
So there is an incompatibility between Windows 10 and TComPort, setting the compatibility, or by running the program as an administrator does not change anything.
How can I fix?
I have to use another library for serial communication?
Here's a test I've done
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, CPort;
type
TForm1 = class(TForm)
ComPort1: TComPort;
Memo1: TMemo;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
var List:TStringList;
sPortName:String;
I:integer;
begin
List := TStringList.Create;
try
EnumComPorts( List );
For I := 0 to List.Count-1 do
begin
sPortName := Trim(List[I]);
Memo1.Lines.Add(sPortName);
end;
finally
List.Free;
end;
end;
end.
This is the result
The string "sPortName" is 3 characters long.

I have had issues in the past with TComPort returning port names. TComPort is working fine for me here with Windows 10. I have found it is necessary to use Trim() on each returned port name since #0 characters can get returned at the end of the port name. You do not provide any useful debugging info but this may be contributing to your issue. The solution is simple. I do:
List := TStringList.Create;
try
EnumComPorts( List );
For I := 0 to List.Count-1 do
begin
sPortName := Trim(List[I]);
<<< do something with sPortName >>>
end;
finally
List.Free;
end;

Related

How to add support of HTML help files (.chm) on Delphi XE2?

How to add support of HTML help files (.chm) on Delphi XE2? We need to use A-links (A-keywords) on HelpContext property of every control to lookup help pages. Delphi XE2 has native support of HTML help files by unit HTMLHelpViewer. But how to use it?
It's not hard with F1 jump to a context.
Select Edit1 and press F1 . Help opens and Overview.htm is shown.
Prerequisite.
Edit1 Help settings:
sample.chm source settings.
sample.ali
IDH_Overview=Overview.htm
IDH_welcom=FirstTopic.htm
IDH_UsingtheMenus=Overview.htm
sample.h
#define IDH_Creating_Projects_and_Topics 1005
#define IDH_Overview 1003
#define IDH_UsingtheMenus 1009
Unit1.pas
unit Unit1;
interface
uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, HTMLHelpViewer, Vcl.ExtCtrls;
type
TForm1 = class(TForm)
HHALINKLOOKUP: TButton;
JumpAnchor: TButton;
Edit1: TEdit;
Label1: TLabel;
procedure FormCreate(Sender: TObject);
procedure HHALINKLOOKUPClick(Sender: TObject);
procedure JumpAnchorClick(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
var
hpPath : string;
link : HH_AKLINK;
procedure TForm1.FormCreate(Sender: TObject);
begin
hpPath := ExtractFilePath(Application.ExeName) +
'HelpFile\sample.chm';
Application.HelpFile := hpPath;
end;
procedure TForm1.HHALINKLOOKUPClick(Sender: TObject);
var
link : HH_AKLINK;
szUrl,szKey,szMsgText,szMsgTitle,szWindow : AnsiString;
begin
szKey := Edit1.Text; // 'UsingtheMenus';
szUrl :='Overview.htm';
szMsgText :='Error: Can''t find "'+Edit1.Text+'"!';
szMsgTitle :='Error: HH_ALINK_LOOKUP';
szWindow :='main';
with link do begin
cbStruct := sizeof(HH_AKLINK) ;
fReserved := False;
pszKeywords := PChar(szKey);
pszUrl := nil;
pszMsgText := PChar(szMsgText);
pszMsgTitle := PChar(szMsgTitle);
pszWindow := PChar(szWindow);
fIndexOnFail:= False;
end;
HtmlHelpW(0, hpPath+'>main', HH_DISPLAY_TOPIC, DWORD_PTR(nil));
HtmlHelpW(0, hpPath, HH_ALINK_LOOKUP, DWORD_PTR(#link));
end;
procedure TForm1.JumpAnchorClick(Sender: TObject);
begin
HtmlHelpW(0, hpPath+'::/Overview.htm#'+Edit1.Text+'>main', HH_DISPLAY_TOPIC, DWORD(nil));
end;
end.
Here is a ready to use sample.chm and the source Download
There is a trick how to easily, to jump, not only to the .htm file but jumps directly to an anchor.
Change sample.ali
IDH_Overview=Overview.htm
IDH_welcom=FirstTopic.htm
IDH_UsingtheMenus=Overview.htm#UsingtheMenus
Insert an anchor at the place, you want to jump to in Overview.htm
[...]
<A NAME="UsingtheMenus" </A>
<P><STRONG>Using the Menus and Toolbars</STRONG>
<P>The menus and toolbars provide a complete set of tools
[...]
Now it is possible with F1, jump directly to the desired point in overview.htm.
I suspect that to use A-links you need to do the following:
Assign an Application.OnHelp handler as described below.
Assign Application.HelpFile during program startup.
Call Application.HelpKeyword if you wish to invoke the help system with an A-link.
Set the HelpKeyword property for any GUI controls that you wish to respond to context sensitive F1 key presses.
The OnHelp handler looks like this:
function TMainForm.ApplicationHelp(Command: Word;
Data: THelpEventData; var CallHelp: Boolean): Boolean;
var
Link: THH_AKLink;
ALink: string;
begin
CallHelp := False;
Result := True;
//argh, WinHelp commands
case Command of
HELP_COMMAND:
begin
ZeroMemory(#Link, SizeOf(Link));
Link.cbStruct := SizeOf(Link);
ALink := PChar(Data); // we are going to re-purpose the keyword as an A-link
Link.pszKeywords := PChar(AnsiString(ALink)); // seems we have to pass a PAnsiChar ..
Link.fIndexOnFail := True;
HtmlHelp(GetDesktopWindow, Application.HelpFile, HH_ALINK_LOOKUP,
DWORD_PTR(#Link));
end;
end;
end;
The HtmlHelpViewer unit contains methods named LookupALink which do the same. But I don't see how they could ever be called.
The above approach is a little bit hacky because it interprets keywords as A-Links. If you want context sensitive help, I can't see what else you can do.
Not sure how Xe2 viewer works (I'm on 2007) but I just use Eric Granges port of the Microsoft HTML help API, which unsurprisingly, is called HTMLhelpAPI.pas.
You can call an Alink using the function
ChmShowTopic(const filename,atopic:string):HWND;

Different behavior of interface between Delphi 7 and Delphi XE and higher

I am having a strange problem of using interface in different versions of Delphi. The following minimized code compiles and runs as expected in Delphi XE and higher but not in Delphi 7. Specificaly, it seems when compiling in Delphi 7, the function TForm1.Load: IMoleculeSubject; does not returns the correct result, i.e., the correct reference to the newly created instance. Could you help to comment about the reason and possible workaround? Many thanks!
uInterface.pas
unit uInterface;
interface
type
IMoleculeSubject = interface
['{BEB4425A-186C-45DF-9DCE-C7175DB0CA90}']
end;
TMoleculeSubject = class(TInterfacedObject, IMoleculeSubject)
end;
implementation
end.
uBusiness.pas
unit uBusiness;
interface
uses
uInterface;
type
TMoleculeDecorator = class(TMoleculeSubject)
private
FID: Integer;
public
property ID: Integer read FID;
constructor Create;
end;
implementation
{ TMoleculeDecorator }
constructor TMoleculeDecorator.Create;
begin
inherited Create;
FID := Random(100);
end;
end.
Unit1.pas
unit Unit1;
interface
uses
uInterface, uBusiness,
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls,
Forms, Dialogs;
type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
private
function Load: IMoleculeSubject;
public
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
var
MolSubject: IMoleculeSubject;
begin
MolSubject := Load;
// The down-cast is to show the returned result is wrong in Delphi 7!
Caption := IntToStr(TMoleculeDecorator(MolSubject).ID);
end;
function TForm1.Load: IMoleculeSubject;
var
MolSubject: IMoleculeSubject;
begin
MolSubject := TMoleculeDecorator.Create;
Result := MolSubject;
end;
end.
The Load function works perfectly well in all versions of Delphi. The problem is your cast, which is what is known as an unsafe typecast. An unsafe typecast from an interface reference to an object has ill-defined behaviour in older versions of Delphi. However, the behaviour is well-defined in modern Delphi. The documentation says more.
So, the basic problem is that your expectations for the behaviour are not compatible with the Delphi 7 version of the language.
If you get the interface to return the ID you will find that the interface you are creating is as expected.
program InterfaceDemo;
{$APPTYPE CONSOLE}
uses
Classes;
type
IMyIntf = interface
function GetID: Integer;
end;
TImplementingObject = class(TInterfacedObject, IMyIntf)
private
FID: Integer;
function GetID: Integer;
public
constructor Create;
end;
{ TImplementingObject }
constructor TImplementingObject.Create;
begin
FID := Random(100);
Writeln(FID);
end;
function TImplementingObject.GetID: Integer;
begin
Result := FID;
end;
var
MyIntf: IMyIntf;
begin
Randomize;
MyIntf := TImplementingObject.Create;
Writeln(MyIntf.GetID);
Readln;
end.
It's rather unusual to ask for the implementing object from an interface. To do so suggests that there is a problem with your design. Should you really need to do so there are a few options:
In modern Delphi you can use the type-safe case with the as operator.
In older Delphi versions there are hacks that retrieve the implementing object: Casting a delphi interface to its implementation class without modifying the interface
You could add a function to the interface that returns the implementing object.
The latter option works in all versions of Delphi and does so without resorting to subterfuge.
Casting interfaces to objects is available since Delphi 2010. Where are workarounds for older Delphi versions, see for example How to cast a Interface to a Object in Delphi

Problems with using free DBX driver in conjunction with TSQLConnection

I've downloaded free DBX driver from here.
I am trying to make it work since two days now, without success.
Here is the snapshot of my code:
unit uMainForm;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, SqlExpr, WideStrings, DBXDynalink, DB;
type
TMainForm = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
MainForm: TMainForm;
implementation
{$R *.dfm}
procedure TMainForm.Button1Click(Sender: TObject);
var C: TSQLConnection;
begin
C := TSQLConnection.Create(Self);
try
C.DriverName := 'FirebirdConnection';
C.LibraryName := 'dbxfb4d12.dll';
C.VendorLib := 'fbclient.dll';
C.GetDriverFunc := 'getSQLDriverFIREBIRD';
C.Params.Add('User_Name=SYSDBA');
C.Params.Add('Password=masterkey');
C.Params.Add('Database=C:\MyDB.fdb');
C.Open;
if C.Connected then
ShowMessage('Connection is active')
finally
C.Free;
end;
end;
After running the test I am receiving error: "Unable to load fbclient.dll(ErrorCode 22). It may be missing from the system path."
I have required libraries in my application path, I have them even in the System32 path. I am not using dbxdrivers.ini and dbxconnections.ini.
So what is going on here? I have Delphi 2009 with latest updates.
Thanks for your time.
Did you also try to put the fbclient.dll file in the same folder as the executable?
Sometimes it's necessary to have the fbclient.dll renamed to gds32.dll. It might do the trick.

Delphi 2010: unable to find resource - EResNotFound

Based on examples at for instance here, here, and here, I'm trying to include SVN revision info in a project. The result of a svn info call is stored in rev.txt (it's a plain ansi file). My revinfo.rc looks like this:
REV_TEXT TEXT rev.txt
My project looks like this:
unit rev;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm2 = class(TForm)
Memo1: TMemo;
Button1: TButton;
procedure Button1Click(Sender: TObject);
end;
var
Form2: TForm2;
implementation
{$R *.dfm}
{$R revinfo.res}
procedure TForm2.Button1Click(Sender: TObject);
var
RS : TResourceStream;
MyStr : AnsiString;
begin
RS := TResourceStream.Create(hInstance, 'REV_TEXT', RT_RCDATA);
SetLength(MyStr, RS.Size);
RS.Read(MyStr[1], RS.Size);
RS.Free;
Memo1.Text := MyStr;
end;
end.
The project compiles, in other words, the resource file itself is located by the compiler (or perphaps it is the linker?). Anyway; when the statement TResourceStream.Create(hInstance, 'REV_TEXT', RT_RCDATA); is executed, I get an EResNotFound exception, complaining it can't find resource REV_TEXT. I can confirm that the resource file is compiled satisfactory, containing the content of the rev.txt text file. Are there anyone out there who're able to reproduce my troubles?
BTW: I've also tried to use the indexed version of the TResourceStream-constructor, but I don't know which index to use (tried 0, 1, and 2 to no avail).
I really appreciate your help! :)
The problem in your code is the line:
TResourceStream.Create(hInstance, 'REV_TEXT', RT_RCDATA);
You must call the TResourceStream.Create with the same type of the resource TEXT.
The following code should work:
var
RS : TResourceStream;
MyStr : AnsiString;
begin
RS := TResourceStream.Create(hInstance, 'REV_TEXT', 'TEXT');
try
SetLength(MyStr, RS.Size);
RS.Read(MyStr[1], RS.Size);
finally
RS.Free;
end;
end;

GetDir in Delphi2010 not working under Windows 7?

I have the following sequence of commands in Delphi2010:
var netdir:string;
....
OpenDialog1.InitialDir:=netdir;
....
OpenDialog1.Execute...
....
GetDir(0,netdir);
....
After executing OpenDialog I should have in string netdir the directory where I finished
my OpenDialog.Execute. And in the next OpenDialog.Execute it should start from that
directory.
It works fine on XP, but not on Windows 7?
It always starts from directory where the program is installed.
Any idea what might be wrong?
Thanks.
Your question cannot be answered as it stands, because it lacks several crucial details.
Is netdir a global constant, or does it go out of scope every now and then?
Do you set netdir to something prior to OpenDialog1.Execute?
Is the question about what directory GetDir return (as your title suggests), or about how to make the open dialog remember the last visited directory (as the body matter suggests)?
I will assume that 1) netdir is a global constant, that 2) you do not set it initially, and that 3) you want the open dialog to remember the last visited folder. Thus you have something like
unit Unit3;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs;
type
TForm3 = class(TForm)
OpenDialog1: TOpenDialog;
procedure FormClick(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form3: TForm3;
var
netdir: string;
implementation
{$R *.dfm}
procedure TForm3.FormClick(Sender: TObject);
begin
OpenDialog1.InitialDir := netdir;
OpenDialog1.Execute;
GetDir(0, netdir);
end;
end.
Then the solution is to let Windows remember the directory for you, that is, simply do
procedure TForm3.FormClick(Sender: TObject);
begin
OpenDialog1.Execute;
end;
alone! But why doesn't your method work? Well, GetDir doesn't return what you want. If you need explicit control, do
procedure TForm3.FormClick(Sender: TObject);
begin
OpenDialog1.InitialDir := netdir;
OpenDialog1.Execute;
netdir := ExtractFilePath(OpenDialog1.FileName)
end;
If you not wan´t opendialog you can do as below to get dir under your program.
yourdir:=ExtractFilePath(Application.ExeName);
I have done it in Vista and it work.
This is the solution for the problem
openDialog1.Options := [ofFileMustExist];
if openDialog1.Execute then
begin
end;

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