Chamada app Client

procedure TfrmPrincipal.Compras;
var
    json, erro: string;
    jsonArray : TJSONArray;
    x : integer;
begin
  try
    dmPrincipal.Request_Compras.Resource:= 'Compras';
    dmPrincipal.Request_Compras.Params.Clear;
    dmPrincipal.Request_Compras.AddParameter('dtini', dtIni.Text);
    dmPrincipal.Request_Compras.AddParameter('dtfim', dtFim.Text);

    //escolha das filiais
    if rdbMT.IsChecked then
    begin
      dmPrincipal.Request_Compras.AddParameter('filial',rdbMT.Tag.ToString);
    end
    else
    if rdbRN.IsChecked then
    begin
      dmPrincipal.Request_Compras.AddParameter('filial',rdbRN.Tag.ToString);
    end
    else
    if rdbTodos.IsChecked then
    begin
      dmPrincipal.Request_Compras.AddParameter('filial','1,4');
    end;
    //escolha da variedade
    if rdbPapaya.IsChecked then
    begin
      dmPrincipal.Request_Compras.AddParameter('variedade', rdbPapaya.Tag.ToString);
    end
    else
    if rdbFormosa.IsChecked then
    begin
      dmPrincipal.Request_Compras.AddParameter('variedade', rdbFormosa.Tag.ToString);
    end
    else
    if rdbTodas.IsChecked then
    begin
      dmPrincipal.Request_Compras.AddParameter('variedade', '195, 193' );
    end;

    dmPrincipal.Request_Compras.Execute;
  Except
    raise Exception.Create('Erro ao Listar Compras');
  end;

  if dmPrincipal.Request_Compras.Response.JSONValue <> nil then
  begin
    try
      json:= dmPrincipal.Request_Compras.Response.JSONValue.ToString;
      jsonArray:= TJSONObject.ParseJSONValue(TEncoding.UTF8.GetBytes(json),0) as TJSONArray;

      for x := 0 to jsonArray.Size -1 do
        begin
          VLR:= jsonArray.Get(x).GetValue<Double>('VLR');
          Label11.Text:= FormatFloat('R$ ###,###,##0.00', VLR);

          PESO:= jsonArray.Get(x).GetValue<Double>('PESO');
          Label15.Text:= FormatFloat('###,###,##0.00', PESO);

          VLRMEDIOCOMPRA:= jsonArray.Get(x).GetValue<Double>('VLRMEDIOCOMPRA');
          Label13.Text:= FormatFloat('###,###,####0.0000', VLRMEDIOCOMPRA);
        end;

        if erro = '' then
        begin
          Label11.Text:= '0,00';
          Label15.Text:= '0,00';
          Label13.Text:= '0,00';
        end;

        if erro <> '' then
        begin
          raise Exception.Create(erro);
          exit;
        end;
    finally
    end;
  end;
end;