I'm trying to use embedded mysql database using libmysqld.dll (mysql 5.1) with zeos (7.0.3) in Delphi XE
i put libmysqld.dll in the same directory,
folder language\errmsg.sys
folder data\belajar\biodata.frm,biodata.MYD,biodata.MYI,db.opt
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ZAbstractConnection, ZConnection;
type
TForm1 = class(TForm)
Button1: TButton;
ZCon: TZConnection;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
begin
ZCon.Protocol := 'mysqld-5';
zcon.Database := 'belajar';
zcon.Connect;
end;
end.
When i run the code, click the button1 and then it just closed, no error message, the application terminated.
any help?
update:
i have solved this problem, i put the wrong name and version of "language" folder, it should be "share" folder and errmsg.sys in the english subfolder
thankyou everyone
Related
When I use setstate I always get this error: unit1.pas(34,49) Error: Only class methods, class properties and class variables can be referred with class references, why does this error occur? I think the error lays in ssNoDelay, as without it the before mentioned error doesn't happen.
I made this empty project as an example:
{$mode objfpc}{$H+}
interface
uses
Classes, SysUtils, Forms, Controls, Graphics, Dialogs, lNetComponents, lNet;
type
{ TForm1 }
TForm1 = class(TForm)
LTCPComponent1: TLTCPComponent;
procedure FormCreate(Sender: TObject);
private
public
end;
var
Form1: TForm1;
implementation
{$R *.lfm}
{ TForm1 }
procedure TForm1.FormCreate(Sender: TObject);
begin
LTCPComponent1.SocketClass.SetState(ssNoDelay);
end;
end.
SetState has to be used on a TLSocket, not on the TLCTPComponent. This means you can only use SetState when you already have a connection you want to apply one of the options (ssNoDelay for example) on (so the best solution is to use setstate in the OnAccept / OnConnect procedure if you want to use an option from the start).
The following code end up in an exception
'2019.10.5 14:16:14,1000' is not a valid date and time
when trying to parse the json to an object. The problem seems to be the decimal in the date.
JSonStr := '{"orderNumber": "395409772020_1", "modified": "2019-10-05T14:16:14.9995946Z"}';
Order := TJson.JsonToObject<TOrder>(JSonStr);
If I use a date with millisecond precision that rounds downwards i.e "modified": "2019-10-05T14:16:14.4995946Z" it works fine.
I've tried adding options to set the format for the date. Order := TJson.JsonToObject<TOrder>(JSonStr, [joDateFormatParse]);. This prevents the code from crashing, but the DateTime is not recognized and the value ends up with "0".
Anyway around this, or is it simply a bug in the library?
I'm running Delphi 10.2 Update 3
I built a simple demo program with your code and it works perfectly with Delphi 10.4.1.
Here is the source code for the demo:
unit JsonParseDateDemoMain;
interface
uses
Winapi.Windows, Winapi.Messages,
System.SysUtils, System.Variants, System.Classes,
Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls,
REST.Json;
type
TForm1 = class(TForm)
Button1: TButton;
Memo1: TMemo;
procedure Button1Click(Sender: TObject);
end;
type
TOrder = class
private
FOrderNumber : String;
FModified : TDateTime;
published
property OrderNumber : String read FOrderNumber write FOrderNumber;
property Modified : TDateTime read FModified write FModified;
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
var
JsonStr : String;
Order : TOrder;
begin
JsonStr := '{"orderNumber": "395409772020_1", ' +
'"modified": "2019-10-05T14:16:14.9995946Z"}';
Order := TJson.JsonToObject<TOrder>(JsonStr);
Memo1.Lines.Add(Order.OrderNumber);
Memo1.Lines.Add(DateTimeToStr(Order.Modified));
Order.Free;
end;
end.
It is a bug in Delphi version you use.
I want to edit a property of a shape inside a procedure.
However if I create my own procedure I get an "undefinded identifier" error.
I tried to edit the property in the OnCreate event procedure of my form and that works just fine.
Why is it like that and how can I fix it?
unit Unit1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ExtCtrls;
type
Tfrm_main = class(TForm)
shp_wheelLeftInside: TShape;
shp_wheelRightInside: TShape;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
frm_main: Tfrm_main;
implementation
{$R *.dfm}
procedure addWheelInsides();
begin
shp_wheelRightInside.Height := 42; //this is where the error occurs
end;
procedure Tfrm_main.FormCreate(Sender: TObject);
begin
shp_wheelLeftInside.Height := 42;
shp_wheelRightInside.Height := 42;
addWheelInsides();
end;
end.
The problem is that shp_wheelRightInside is a field that belongs to your Tfrm_main class whereas the addWheelInsides() method you have declared as a naked, ordinary method that belongs to nothing. The method, therefore, does not have access to the fields which belong to the form.
One solution is to move the method, which intends to operate on objects owned by the form, into the form itself.
Tfrm_main = class(TForm)
shp_wheelLeftInside: TShape;
shp_wheelRightInside: TShape;
procedure FormCreate(Sender: TObject);
private
procedure addWheelInsides(); {declare it here}
public
{ Public declarations }
end;
Which you then implement as a method of the form class as :
procedure Tfrm_main.addWheelInsides();
begin
shp_wheelRightInside.Height := 42;
end;
The shp_wheelRightInside field is not visible in your procedure.
Declare the procedure addWheelInsides() inside the form as a method instead to resolve the shp_wheelRightInside scope.
type
Tfrm_main = class(TForm)
shp_wheelLeftInside: TShape;
shp_wheelRightInside: TShape;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
procedure addWheelInsides;
public
{ Public declarations }
end;
If you want to extend the procedure across several units, pass TShape as a parameter instead.
I'm trying to serialise/deserialise the TMySerializableClass declared in the below unit:
unit Unit6;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Generics.Collections, System.SyncObjs, DBXJSon,
DBXJSonReflect;
type
TForm6 = class(TForm)
Button1: TButton;
Memo1: TMemo;
procedure Button1Click(Sender: TObject);
private
public
{ Public declarations }
end;
TMySerializableClass<T> = class
MyStringField: string;
MyIntegerField: Integer;
MyBooleanField: Boolean;
end;
var
Form6: TForm6;
implementation
{$R *.dfm}
procedure TForm6.Button1Click(Sender: TObject);
var
Mar: TJSONMarshal; //Serializer
UnMar: TJSONUnMarshal; //UnSerializer
SerializedObject: TJSONObject;
aMySerializableClass1: TMySerializableClass<Integer>;
aMySerializableClass2: TMySerializableClass<Integer>;
aString: string;
begin
try
aMySerializableClass1:= TMySerializableClass<Integer>.Create;
aMySerializableClass2:= TMySerializableClass<Integer>.Create;
Mar:= TJSONMarshal.Create(TJSONConverter.Create);
try
SerializedObject := Mar.Marshal(aMySerializableClass1) as TJSONObject;
finally
Mar.Free;
end;
Memo1.Text:= SerializedObject.ToString;
// UnMarshalling Kid
UnMar := TJSONUnMarshal.Create;
try
aMySerializableClass2 := UnMar.UnMarshal(SerializedObject) as TMySerializableClass<Integer>;
finally
UnMar.Free;
end;
finally
aMySerializableClass1.Free;
aMySerializableClass2.Free;
end;
end;
end.
When I serialise it everything works fine, while when deserialise to a new instantiated variable of the same kind I got the following error:
First chance exception at $74E5C41F. Exception class EConversionError with message 'Internal: Cannot instantiate type Unit6.TMySerializableClass<System.Integer>'. Process Project7.exe (2252)
Edit: this has something to do with the TMySerializableClass<T>, which
is a generic. If I declare it as TMySerializableClass the
deserialisation works fine.
Ideas?
Cannot test on XE5 but on Berlin 10.1 it worked for me after I added alias for instance of generic type as
TMySerializableClassInteger = TMySerializableClass<Integer>;
looks like Delphi does not generate RTTI information if you don't do it.
UPDATE. Seems Delphi does not need alias but just have some declaration of specialized class in interface part of the unit. So if you declare variable or form field as TMySerializableClass<Integer> it will also work.
I am currently working on a program that should download the HTML file of an Wikipedia Page and then convert it from HTML to PDF.
My program so far downloads the HTML file, but without any pictures and the page looks incomplete.
Is there any way I can bring the idhttp.get component from the INDY Package to download the full HTML file?
unit Unit3;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls,Forms,
Dialogs, StdCtrls, IdBaseComponent, IdComponent, IdTCPConnection,
IdHTTP;
type
TForm3 = class(TForm)
Label1: TLabel;
Button1: TButton;
Button2: TButton;
IdHTTP1: TIdHTTP;
SpeicherEd: TEdit;
SaveDialog1: TSaveDialog;
AuswahlB: TButton;
NameEd: TEdit;
procedure Button1Click(Sender: TObject);
procedure NameEdEnter(Sender: TObject);
procedure AuswahlBClick(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Speicherort, Form3: TForm3;
implementation
uses
unit2, unit1, Filectrl;
{$R *.dfm}
procedure TForm3.Button1Click(Sender: TObject);
var ResponseStream: TFileStream;
begin
ResponseStream := TFileStream.Create(SpeicherEd.Text, fmCreate);
try
idHTTP1.Get(url, ResponseStream);
finally
ResponseStream.Free;
end;
ShowMessage('Download abgeschlossen');
end;
procedure TForm3.AuswahlBClick(Sender: TObject);
var dir : String;
begin
dir := ExtractFilePath(Application.ExeName);
if SelectDirectory ('Bitte ein Verzeichnis auswählen','',Dir)
then
SpeicherEd.Text := (dir+'\'+NameEd.text+'.html');
end;
procedure TForm3.NameEdEnter(Sender: TObject);
begin
NameEd.Text := '';
end;
end.