Android crashes in formula

[erva 2]

Hi,

 

Android TLocation.LocationChanged crashes when executing code at line where variable lstDistance is calculated. iOS works fine. I have tried Double type instead of Extended type but with no help. In iOS both types work fine. If i change lstDistance := 1;, code works fine.

 

Code is working Taximeter where charge is counted based on distance and time:)

 

procedure TfrmMain.senLocationLocationChanged(Sender: TObject; const OldLocation,
  NewLocation: TLocationCoord2D);
var
  Latitude1: Extended;
  Longitude1: Extended;
  Latitude2: Extended;
  Longitude2: Extended;
  lstDistance: Extended;
begin

  //MATKAN MITTAUS
  Latitude1 := OldLocation.Latitude;
  Longitude1 := OldLocation.Longitude;
  Latitude2 := NewLocation.Latitude;
  Longitude2 := NewLocation.Longitude;
  lstDistance := ArcCos(Sin(DegToRad(Latitude1)) * Sin(DegToRad(Latitude2)) + Cos(DegToRad(Latitude1)) * Cos(DegToRad(Latitude2)) * Cos(DegToRad(Longitude2 - Longitude1))) * 6367000;

 

// THESE LINES I HAVE COMMENTED OUT TO MAKE SURE THEY DON*T CAUSE CRASHING

//  lstDistance := lstDistance * 1.01; //Calibrointi
//  totDistance := totDistance + lstDistance;
//
//  //COUNT OF MEASUREMENTS
//  mitattuKpl := mitattuKpl + 1;
//
//  //DISTANCE IN EUROS
//  matkaE := totDistance * (0.99 / 1000);
//

// TIME IN EUROS
//  aikaLopetus := Now;
//  kyydinKesto := aikaLopetus - aikaAloitus;
//  aikaE := ((24*60)*0.89)*kyydinKesto;
//  summaE := lahtoE + matkaE + aikaE;
//
//  //UPDATE LABELS
//  lblLongitude.Text := Format('%2.6f', [NewLocation.Longitude]);
//  lblLatitude.Text := Format('%2.6f', [NewLocation.Latitude]);
//  lblMitattu.Text := Format('%2.2f', [lstDistance]);
//  lblMatka.Text := Format('%2.2f', [totDistance]);
//  lblMittauksia.Text := IntToStr(mitattuKpl);
//  lblLahto.Text := Format('%2.2f', [lahtoE]);
//  lblKmE.Text := Format('%2.2f', [matkaE]);
//  lblAikaE.Text := Format('%2.2f', [aikaE]);
//  lblSumma.Text := Format('%2.2f', [summaE]);

end;
 

[Dave Nottage 557]

On iOS, the first location change has values of 0 for OldLocation.Latitude and OldLocation.Longitude. On Android, they're both NaN, so your code will fail in that case. You should do this check (at least):

    if not IsNan(Latitude1) and not IsNan(Longitude1) then

 

[erva 2]

Yes, now it's working. Thank you!