Class segmentation fault (11)

问题

Please follow the steps below:

1. Create New Firemonkey Moblie Application
2. Add TGeustureManager component to the Form

3. Add 2 TButton components to the Form

   • Button1.Text: "Button1: Do something..."
   • Button2.Text: "Button2: Exit Application..."
   

4. Double click on Button2 Component and write the following code for OnClick Event:

   procedure TForm1.Button2Click(Sender: TObject);
   begin
     if MessageDlg('Are you sure you want to Exit?', TMsgDlgType.mtWarning,
             [TMsgDlgBtn.mbYes, TMsgDlgBtn.mbNo], 0) = mrYes then
       SharedActivity.finish;
   end;
   

5. Run the application in debug mode.

6. on the device, click the button 2, then click yes to the popped up message. An exception will appear:

   

Why is this exception raised?

I thought it is related to unused TGeustureManager component. but NO it is NOT:

1. If you open the Location Demo project that comes with Delphi xe5.
2. Add TButton component to Location Label as shown in the image below:
   

3. Add the same code as above to OnClick Event.
4. Run the application, and click on Button5, you will get the same exception.

Is this a bug should I report? or am I doing something wrong?

回答1:

Possibly that you are killing the activity that is running, before its execution flow has been exhausted, thereby causing problems. Much like freeing a form in a form method....

What happens if you replace:

SharedActivity.finish

with:

uses
  FMX.Helpers.Android;
...
CallOnUIThread(procedure begin SharedActivity.finish end);

[ Typed from memory, so may need some tweaking ]

回答2:

if you want only to close application un can try this:

case MessageDlg('Close Application?', System.UITypes.TMsgDlgType.mtInformation,
    [
      System.UITypes.TMsgDlgBtn.mbYes,
      System.UITypes.TMsgDlgBtn.mbNo
    ], 0) of
    { Detect which button was pushed and show a different message }
    mrNo:
      showmessage('');
    mrYes:
      halt;
  end;

回答3:

I have contacted Embarcadero for this issue.

They said that it is because TApplication.Terminate is not yet implemented in FireMonkey platform for mobile.

They open a ticket to implement TApplication.Terminate in nex hot fix.

Let's hope that will not take ages.

回答4:

I have the same error on a very simple Location test app, it happens when setting text on a label. The label was set to auto size, and when I changed it to a static size the error went away.

Delphi XE6, line 681 in FMX.TextLayout.GPU

I am using a Samsung S4 phone.

procedure TForm_StayTogether.LocationSensor1LocationChanged(Sender: TObject;
  const OldLocation, NewLocation: TLocationCoord2D);
begin
  DistLabel.Text:= FloatToStr(LocationSensor1.Distance);
  AccLabel.Text:= FloatToStr(LocationSensor1.Accuracy);
  LatLabel.Text:= FloatToStr(NewLocation.Latitude);
  LonLabel.Text:= FloatToStr(NewLocation.Longitude);
end;

回答5:

I've just experienced something similar, a very tiny app with little code giving this same error (Segmentation fault 11) every single time I quit the app on the Android device (Galaxy Note 2 in my case).

For what it's worth, the problem disappeared when I went to the Stylebook I had earlier put on the form and cleared it. I think I had earlier copied that Stylebook from another test unit.

Mike

来源：https://stackoverflow.com/questions/19875029/class-segmentation-fault-11