Thiết kế website giá rẻ

Question

Delphi 11.1

I need to start an Android Service which stays running even if the app is closed by the user or killed by the OS. The app has an SQLite database in the documents folder and the service needs to access this database and insert some data for a long time.

I’ve tried a lot of strategies, but none worked.

My main attempt is about creating a local service, using the START_STICKY and calling StartForeground() in the StartCommand event.

Service data module:

unit UDMService;

interface

uses
  System.SysUtils,
  System.Classes, System.IOUtils,
  System.Android.Service,
  AndroidApi.JNI.GraphicsContentViewText,
  Androidapi.JNI.Os, FireDAC.Stan.Intf, FireDAC.Stan.Option, FireDAC.Stan.Error,
  FireDAC.UI.Intf, FireDAC.Phys.Intf, FireDAC.Stan.Def, FireDAC.Stan.Pool,
  FireDAC.Stan.Async, FireDAC.Phys, FireDAC.Phys.SQLite, FireDAC.Phys.SQLiteDef,
  FireDAC.Stan.ExprFuncs, FireDAC.ConsoleUI.Wait, FireDAC.DApt,
  FireDAC.Phys.SQLiteWrapper.Stat, Data.DB, FireDAC.Comp.Client;

type
  TThreadTeste = class(TThread)
  protected
    procedure Execute; override;
  end;
  TDM = class(TAndroidService)
    fdConDados: TFDConnection;
    FDPhysSQLiteDriverLink1: TFDPhysSQLiteDriverLink;
    function AndroidServiceStartCommand(const Sender: TObject;
      const Intent: JIntent; Flags, StartId: Integer): Integer;
  private
    { Private declarations }
    FThreadGravarTabela: TThread;
    procedure ConectarBanco;
    procedure GerarRegistroTabela;
    procedure GerarRegistrosTabela;
    procedure StartForeground;
  public
    { Public declarations }
  end;

var
  DM: TDM;

implementation

{%CLASSGROUP 'FMX.Controls.TControl'}

{$R *.dfm}

uses Androidapi.JNI.App, Androidapi.JNI.Support, Androidapi.Helpers;

procedure TDM.StartForeground;
var
  {$if COMPILERVERSION > 34}
  LBuilder: Japp_NotificationCompat_Builder;
  {$else}
  LBuilder: JNotificationCompat_Builder;
  {$endif}
begin
  try
    //if FIsForeground or not TAndroidHelperEx.CheckBuildAndTarget(26) then
    //Exit; // <======
    LBuilder := TJapp_NotificationCompat_Builder.JavaClass.init(TAndroidHelper.Context);
    LBuilder.setAutoCancel(True);
    LBuilder.setContentTitle(StrToJCharSequence('Sample'));
    LBuilder.setContentText(StrToJCharSequence('Monitoring location changes'));
    LBuilder.setSmallIcon(TAndroidHelper.Context.getApplicationInfo.icon);
    LBuilder.setTicker(StrToJCharSequence('Sample 2'));
    TJService.Wrap(System.JavaContext).startForeground(3987, LBuilder.build);
  except
  
  end;
end;

function TDM.AndroidServiceStartCommand(const Sender: TObject;
  const Intent: JIntent; Flags, StartId: Integer): Integer;
begin
  StartForeground;
  ConectarBanco;
  //GerarRegistroTabela;
  GerarRegistrosTabela;
  Result := TJService.JavaClass.START_STICKY;
end;
  
procedure TDM.ConectarBanco;
begin
  fdconDados.Params.Values['Database'] := TPath.Combine(TPath.GetDocumentsPath, 'MyServicePOC.db3');
  fdconDados.Params.Add('SharedCache=False');
  fdconDados.UpdateOptions.LockWait := True;
  fdconDados.Connected := True;
end;

procedure TDM.GerarRegistrosTabela;
begin
  FThreadGravarTabela := TThreadTeste.Create(True);
  FThreadGravarTabela.FreeOnTerminate := FAlse;
  FThreadGravarTabela.Start;
end;
  
procedure TDM.GerarRegistroTabela;
begin
  var AQuery: TFDQuery := TFDQuery.Create(nil);
  AQuery.Connection := fdConDados;
  try
    with AQuery, sql do
    begin
      Clear;
      add('INSERT INTO tabela (data) VALUES (:data)');
      ParamByName('data').AsDateTime := Now;
      ExecSQL;
    end;
  finally
    AQuery.Free;
  end;
end;

{ TThreadTeste }

procedure TThreadTeste.Execute;
begin
  var i: integer := 0;
  var AQuery: TFDQuery := TFDQuery.Create(nil);
  AQuery.Connection := DM.fdConDados;
  try
    while not Terminated do
    begin
      Inc(i);
      try
        with AQuery, sql do
        begin
          Clear;
          add('INSERT INTO tabela (data) VALUES (:data)');
          ParamByName('data').AsDateTime := Now;
          ExecSQL;
        end;
      except
      end;
      Sleep(MSecsPerSec*10); //30 secs
      if i > 10 then
        Terminate;
    end;
  finally
    AQuery.Free;
  end;
end;

end.

Main form from App

unit UMainApp;

interface
    
uses
  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs,
  FMX.Controls.Presentation, FMX.StdCtrls, System.Android.Service,
  FireDAC.Stan.ExprFuncs, FireDAC.Phys.SQLiteWrapper.Stat,
  FireDAC.Phys.SQLiteDef, FireDAC.Stan.Intf, FireDAC.Stan.Option,
  FireDAC.Stan.Error, FireDAC.UI.Intf, FireDAC.Phys.Intf, FireDAC.Stan.Def,
  FireDAC.Stan.Pool, FireDAC.Stan.Async, FireDAC.Phys, FireDAC.Phys.SQLite,
  FireDAC.FMXUI.Wait, Data.DB, FireDAC.Comp.Client, System.IOUtils,
  FMX.Memo.Types, FireDAC.DApt, FMX.ScrollBox, FMX.Memo, FMX.ListView.Types,
  FMX.ListView.Appearances, FMX.ListView.Adapters.Base, FMX.ListView;

type
  TForm1 = class(TForm)
    Button1: TButton;
    FDPhysSQLiteDriverLink1: TFDPhysSQLiteDriverLink;
    fdConDados: TFDConnection;
    mmLog: TMemo;
    ButAtualizarLista: TButton;
    ListView1: TListView;
    procedure butStartServiceClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure ButAtualizarListaClick(Sender: TObject);
  private
    { Private declarations }
    ConexaoServico : TLocalServiceConnection;
    procedure AtualizarEstruturaBase;
    function GetDadosTabelaTestes: TDataSet;
  public
    { Public declarations }
  end;
    
var
  Form1: TForm1;
    
implementation
    
{$R *.fmx}
    
procedure TForm1.AtualizarEstruturaBase;
  function TabelaExiste(const pTable: String): Boolean;
  begin
    var AQuery: TFDQuery := TFDQuery.Create(nil);
    AQuery.Connection := fdConDados;
    try
      AQuery.Open('PRAGMA table_info(' + QuotedStr(pTable) + ')');
      result := AQuery.RecordCount > 0;
    finally
      AQuery.Free;
    end;
  end;
    
const SQL_CRIAR_TABELA_TESTES =
        'CREATE TABLE tabela'
      + ' (id INTEGER PRIMARY KEY AUTOINCREMENT,'
      + ' data DATETIME)';
begin
  var AQuery: TFDQuery := TFDQuery.Create(nil);
  AQuery.Connection := fdConDados;
  try
    if not (TabelaExiste('tabela')) then
      AQuery.ExecSQL(SQL_CRIAR_TABELA_TESTES);
  finally
    AQuery.Free;
  end;
end;
    
procedure TForm1.ButAtualizarListaClick(Sender: TObject);
begin
  ListView1.Items.Clear;
  var ADataSet: TDataSet := GetDadosTabelaTestes;
  with ADataSet do
  begin
    First;
    while not (Eof) do
    begin
      ListView1.Items.Add.Text := Format('%d - %s',
        [FieldBYName('id').AsInteger,
         FormatDateTime('dd/mm/yyyy hh:nn:ss', FieldByName('data').AsDateTime)]);
      Next;
    end;
  end;
end;
    
procedure TForm1.butStartServiceClick(Sender: TObject);
begin
  ConexaoServico := TLocalServiceConnection.Create;
  TThread.CreateAnonymousThread(
    procedure
    begin
      ConexaoServico.StartService('MyService2');
    end).Start;
end;
    
procedure TForm1.FormCreate(Sender: TObject);
begin
  try
    fdconDados.Params.Values['Database'] := TPath.Combine(TPath.GetDocumentsPath, 'MyServicePOC.db3');
    fdconDados.Params.Add('SharedCache=False');
    fdconDados.UpdateOptions.LockWait := True;
    fdconDados.Connected := True;
    AtualizarEstruturaBase;
  except
    on e: exception do
      mmLog.Lines.Add('[TForm1.FormCreate]'+e.Message)
  end;
end;
    
function TForm1.GetDadosTabelaTestes: TDataSet;
begin
  fdConDados.ExecSQL('SELECT * FROM tabela ORDER BY id, data', result);
end;
    
end.

This code runs fine and generates the inserts and I can load the data, but when I close the app the service is killed by the OS as well.

The service was created as “Local”. I tried to created the same project group using the “Remote” option for the service, but the data is not inserted into the app’s database.

Could anyone help with this issue?

Thiết kế website giá rẻ

Danh mục

How to avoid an Android Service being killed when app is closed?