Access variable from one form to another

[DeddyH]

Assuming the ID really belongs to Form1:

Delphi-Quellcode:

type
  TForm1 := class(TForm)
    ...
  private
    FID: integer;
  public
    procedure Person1(NewID: integer);
    property ID: integer read FID;
    ...
  end;

...

(* Looks like a setter, but I am not sure if other interesting things happen here, too *)
procedure TForm1.Person1(NewID:Integer);
begin
  FID := NewID;
end;

Adding Unit1 to the uses-clause of Unit2, you can get the current value simply by calling Form1.ID.

[Blup]

The solution has already been posted, again in detail:

Delphi-Quellcode:

unit unit1;

interface

type
  TForm1 = class(TForm)
    {...}
  private // <- for use self
    FMyPersonID: Integer;
    procedure Person1(ID:Integer);
  public // <- for use to other
    property MyPersonID: Integer read FMyPersonID write FMyPersonID; 
  end;

var
  Form1: TForm1;  // <- Instance of TForm1

implementation

Procedure TForm1.Person1(ID:Integer);<--- i want to use this value of ID in another Form
begin
  FMyPersonID := ID;
end;



unit unit2;

interface

type
  TForm2 = class(TForm)
    {...}
    procedure Button1Click(Sender: TObject);
  end;

implementation

uses
  unit1; // <- knowhow about TForm1, MyPersonID and Form1

Procedure TForm2.Button1Click(Sender: TObject);
begin
//here i want to use the value of ID from TForm1
  Form1.MyPersonID := Form1.MyPersonID + 1;

end;

[question]

I have followed your method, i have clarify my situtaion again, please need some more hints

Procedure TForm1.Person1(ID:Integer);
begin
//The value of this ID come from database with sql query
for example, after query here is the value of ID = 120;
end;


Procedure TForm2.Button1Click(Sender: TObject);
begin
Form1.Person1(Form1.MyPersonID)
//when i call here Form1.MyPersonID, then it passes the value '0' to TForm1.Person1(ID:Integer)
// but , i want to call the value 120
end;

[DeddyH]

I think we need the code of the "Person1"-method. Maybe you want to do a call by reference but actually do a call by value?

[Blup]

The PersonID can alternatively be determined from a query:

Delphi-Quellcode:

unit unit1;

interface

type
  TForm1 = class(TForm)
    {...}
  private // <- for use self
    function GetMyPersonID: Integer;
    procedure SetMyPersonID(AValue: Integer);
  public // <- for use to other
    property MyPersonID: Integer read GetMyPersonID write SetPersonID;
  end;

var
  Form1: TForm1; // <- Instance of TForm1

implementation

procedure TForm1.SetMyPersonID(AValue: Integer);
begin
  FQuery.FieldByName('MyPersonID').AsInteger := AValue;
end;

procedure TForm1.GetMyPersonID: Integer;
begin
  Result := FQuery.FieldByName('MyPersonID').AsInteger;
end;

[question]

Hi,
i have followed what you have suggested but i still got the value '0' .
Now, i wanna do the work in same Unit mot from another

Code:

Procedure TForm1.AddDateTime(Sender:Tobject;  AEvent: TcxSchedulerEvent);
begin

Query.Close();
    QueryKalender.SQL.Text:= 'INSERT INTO Table'
      '(Name`, `NEWID` ..) ' +
    'VALUES ( ' :Name, :NEWID);';

Query.ParamByName('NEWID').AsInteger:= AEventID;
    Query.ExecSQL();
    Query.Close();

  end;

Procedure TForm1.OnDragDrop(Sender, Source: TObject; X,
  Y: Integer);

begin
//here i would like to use the value of AEventID; 
//i cannnot call the procedure AddDateTime(Sender,TcxSchedulerEvent);
//becasue the parameter is different, how can i overcome it ?
end;

[question]

Hi, now its working fine i have written the follwoing

Code:

procedure TForm1.SetMyPersonID(AValue: Integer);
begin
  FQuery.FieldByName('MyPersonID').AsInteger := AValue;
end;

procedure TForm1.GetMyPersonID: Integer;
begin
  Result := FQuery.FieldByName('MyPersonID').AsInteger;
end;

is that ok to write like this, i mean normally in sql query need to query.sql.add/query.sql.open/close... but in this case it is working fine should i need to write the whole query or is that also okay just to write only

Code:

Result := FQuery.FieldByName('MyPersonID').AsInteger;