Questions[delphi]

The problem is the following, I am currently developing a console application which adds two decimal numbers (Numbers of type double), these numbers are received by keyboard. But when doing the calculation, it shows me as a result a number in exp (I think that's what it calls ) and I don't want it to appear that way. I want it to be this way, for example, if we add 2.5 + 3 = 5.5, that is, I show the results as the Windows 10 calculator. The version of Delphi that I am using is 10.4.

Image of the program running (Example):

Here, it should be: 2.5 + 4 = 6.5 only and if the sum is of larger numbers, it gets more confusing.

I would also like you to explain to me why this happens in Delphi, because I have previously made this program in C# and the result is correct, without a lot of complications.

This is the source code:

program Project_Suma;

{$APPTYPE CONSOLE}
{$R *.res}

uses
  System.SysUtils, System.Math;

// Hacer un programa que lea dos números introducidos
// por el teclado y calcule e imprima la suma de los mismos.

begin
    var
    Num_1, Num_2: double;
    Write('Introdusca un numero: ');
    ReadLn(Num_1);

    Write('Introdusca un numero: ');
    ReadLn(Num_2);

    WriteLn('Resultado: ', Num_1 + Num_2);
    ReadLn;

end.

I'm learning and there are things I don't understand. I was reading documentation about creating classes and constructors etc. But I can't understand how it works for what I need. I know that it is something basic and that I am not understanding, let me explain:

I need to create the Dog object from the class TDOG and use it independently as a container to make modifications to it, before assigning it back to the array containing a collection of dogs. But when assigning to the variable DOG , the object vector[i]of the same class, to be able to edit it and later save it in the vector, it is as if any modification in the dog variable, immediately modifies the position of the vector.

    type
    Tperro = class
    nombre : string;
    raza : string;
end

var
vector : array [1..10] of TPerro;

implementation

procedure Tform1.cargarperros; //cargo los perros
    begin
    vector[1]:= TPerro.create
    vector[1].nombre := 'Cubo';
    vector[1].raza := 'caniche';

    vector[2]:= TPerro.create;
    vector[2].nombre :='Chopper';
    vector[2].raza := 'labrador';
end;

procedure TForm1.edicion; // editar Perro, utilizando el objeto "PERRO" y no directamente desde el vector
var perro : TPerro;
begin

Perro := TPerro.create;
Perro := vector[1]; //asigno los datos de vector[1] a variable PERRO

Perro.name := 'Olmedo'; 
Showmessage('Nombre anterior ' + vector[1].name); //aca el nombre sale "olmedo" (cuando deberia salir "CUBO")
Showmessage('Nombre Nuevo ' + Perro.name); //aca sale nombre "olmedo"

vector[1] := Perro //aca vuelvo al vector, y le asigno las modificaciones en el (recipiente) PERRO.

end;

The showmessage( which I use to show you what happens to me ) shows the same thing for both DOG , and for vector[1], when in fact I need that the vector that contains the collection of dogs, not be previously modified, without first verifying the DOG object , to which I make the modifications.

I remember that before using the class ( record ) I did not have these problems. But since I need to add methods to the TPerro class , I need to use it as an Object and not as a record. I don't know if you can add methods to the record class though . Still, I'm learning and need to understand how it works.

Any change you make to the DOG object is made immediately to the array position you previously assigned to it. ( PERRO := vector[1]). Is there something I'm not understanding, or I don't know if I'm missing something, or I should declare the constructor method of the class with some kind of specification.
I hope to explain myself well.

I need your help, because I have tried multiple options and I cannot find the solution: I have this

cadenaEnBase64="ewAiAEQAYQB0AGUAIgA6ACIAMQAxAC8AMAAzAC8AMgAwADIAMQAiACwAIgBJAGQAZQBuAHQAaQB0AHkAIgA6ACIAcwBmAHMAZgBqAGkAZgBuAGQAaQBmAGgAZABmADIANAA2ADQAMQAiACwAIgBEAGEAdABlAEUAcwAiADoAIgAwADEALwAxADIALwAyADAAMgAxACIALAAiAEQAYQB0AGUARQBMACIAOgAiADAAMQAvADEAMgAvADIAMAAyADIAIgAsACIAVABpAHAAbwBzAEwASQBDAEUATgBDAEkAQQAiADoAOQAsACIAQQBjAHQAaQB2AGUAIgA6AHQAcgB1AGUALAAiAEwAaQBjAGUAbgBzAGUAXwBOACIAOgAxADIANQAxAH0A"

I want to decode it to this (this is the result):

{"Date":"11/03/2021","Identity":"sfsfjifndifhdf24641","DateEs":"01/12/2021","DateEL":"01/12/2022","TiposLICENCIA":9,"Active":true,"License_N":1251}

you can test the result at: https://www.base64decode.org/

but with Delphi 10.3 nor 7 I have obtained results, it shows only the first key:

{

That is the only result I get.

Hi, I have the following problem:

I'm trying to create a simple form at runtime where some are displayed TLabel, and I need each one to be centered and at a certain height. I've been able to center them correctly using TLabel.Align := alClientand TLabel.Alignment := taCenter, but I can't get it to the height I need, because TLabel.Layoutit only lets me specify top, center, or bottom.

How can I assign TLabela height value like ClientHeight div 3?

I have this code to create a label:

with TLabel.Create(Self) do
begin
  Align := alClient;
  Alignment := taCenter;
  Top := (F.ClientHeight div 3) * 2;
  caption:= 'Texto de la etiqueta';
  Font.Size:= 18;
  Font.Color := RGB(128, 0, 0);
  Parent:= F;
end;

It seems that when applying Alignand Alignmentit ignores what I specify in Top, then I don't know how to give it the desired value.

EDIT :

I am using Lazarus v1.6RC1in Windows 10. The app is also for Windows 10.

Thanks in advance.

I'm new to delphi/free pascal and I think I have a misconception, since I'm used to java and maybe things can't be approached in the same way. I hope you can help me.

I am using Lazarus v1.6RC1.

I have a class TControlin a unit uControland a class TRedin a unit TRed. The unit uControlhas the unit uRedin uses. The case TControlhas an attribute called FRed, whose type is TRed(is an instance of TRed). The thing is that at a given moment, I need to call a procedure from . My intention is to have access to the instance of from , to be able to access its methods, that's something I did in java, but here it doesn't seem to work. What I am doing is the following:TControlTRedTControlTRed

class TControl:

TControl = class(TObject)
    procedure procesaEntradaRed(pComando : TComando)
public
    FRed : TRed;

class TRed:

TRed = class(TObject)
    constructor Create(pControl : TControl)
public
    FControl : TControl;

When I install TRedit TControlI do it like this:

FRed := TRed.Create(Self);

And the constructor of TRedis like this:

constructor TRed.Create(pControl : TControl)
begin
    FControl := pControl;
end;

The call in which I have the error is this:

FControl.procesaEntradaRed(lComando);

The error message is the following:

uRed.pas(662,12) Error: identifier idents no member "procesaEntradaRed"

I have tried to see which methods were visible TControlfrom TRed, and none of the ones I created in TControlare visible, although the own methods of TObject.

I have put only the parts of the code that are involved in the problem to be concise.

Thanks in advance and sorry for the inexperience.

EDIT:

The line where I make the call is found in uRed, at the end of a procedure whose declaration is:

procedure TRed.UDPRead(AThread: TIdUDPListenerThread; const AData: TidBytes; ABinding: TIdSocketHandle); 

However, commenting out that line throws an error when instantiating TRed, passing Self as a parameter:

FRed := TRed.Create(Self);

The error is the following:

uControl.pas(146,69) Error: Incompatible type for arg no. 3: Got > >"UCONTROL.TControl", expected "CONTROLS.TControl"

It says that parameter 3 fails, it is because I also pass 2 strings, I do not show them so as not to confuse.

The fault seems to be in the Self, but I don't know how to fix it.