It would be helpful if you can file two archives of your reproducible
project on bugzilla - one that works, and one that does not. They would
help spot the difference.
What I tried was exactly from your post, but since it is email and
whitespace differences could matter.
Atsushi Eno
On 2011/08/09 0:56, WyrmUK wrote:
> Well this is just it. It does work perfectly every time some builds, throws
> an exception every time on others (causing the app to crash), and just page
> faults every time on others (again causing the app to crash). This seems to
> point to a mandroid issue because it's not like it sometimes works and
> sometimes page-faults with a single build, if it works for a build then it
> always works in that build; but there may be something I'm missing - or
> there may be a work-around. I can't catch the exception either as it just
> kills the app. Would be good to get some comment from someone who knows more
> about the Mono system and ARM devices and why this might be happening. It
> could be just a byte-alignment issue and a command line option fixes it. But
> I don't know.
> Anyone?
>
>
> Atsushi Eno wrote:
>> Actually, I tried it, but I could never get it working fine. It just
>> shows black screen and ended up with crash (I don't remember correctly).
>> Should this equivalent code work in Java form?
>>
>> Atsushi Eno
>>
>>> Hi.
>>> I'm trying to implement an activity which previews the camera and allows
>>> a
>>> picture to be taken.
>>> However I get rather mixed results with each build. One time it will work
>>> fine, but I might make a change such as adding a comment and re-compile
>>> and
>>> I get an error when setting the ISurfaceHolderCallback, then I might take
>>> the comment out and re-compile and I get a page fault, then I can do
>>> something else and it works again! It seems that it's compile/build
>>> related
>>> because if I build and it happens to work it will always work; but if I
>>> build and it crashes then it will always crash. The below failed with the
>>> exception shown, then I took the '.' off the end of the comment,
>>> re-compiled
>>> and it then worked!!!
>>> Is there an issue here or am I failing to set something up properly?
>>> I'm running this on a Dell Streak 5.
>>>
>>> This is a snapshot from ADB of one of the errors:
>>>
>>> I/ActivityManager( 146): Starting activity: Intent {
>>> cmp=uk.co.reach.reachcloud/reachmobilecc.PictureActivity }
>>> I/CameraView( 2699): Adding Callback
>>> F/PrintK ( 2699):<2>Exception!!! each.reachcloud: unhandled page fault
>>> (11) at 0xed006d4e, code 0x005
>>> I/MonoDroid( 2699): UNHANDLED EXCEPTION: System.NullReferenceException:
>>> Object reference not set to an instance of an object
>>> I/MonoDroid( 2699): at
>>> Android.Views.ISurfaceHolderCallbackAdapter.GetHandle
>>> (Android.Views.ISurfaceHolderCallback)<0x00038>
>>> I/MonoDroid( 2699): at Android.Views.ISurfaceHolderInvoker.AddCallback
>>> (Android.Views.ISurfaceHolderCallback)<0x000bf>
>>> I/MonoDroid( 2699): at ReachMobileCC.PictureActivity.OnResume ()<0x00073>
>>> I/MonoDroid( 2699): at Android.App.Activity.n_OnResume (intptr,intptr)
>>> <0x00033>
>>> I/MonoDroid( 2699): at (wrapper dynamic-method)
>>> object.38c0d09b-61f8-491e-b367-fbed8a6fb14a (intptr,intptr)<0x0002b>
>>> E/mono ( 2699):
>>> E/mono ( 2699): Unhandled Exception: System.NullReferenceException:
>>> Object reference not set to an instance of an object
>>> E/mono ( 2699): at
>>> Android.Views.ISurfaceHolderCallbackAdapter.GetHandle
>>> (ISurfaceHolderCallback instance) [0x00000] in<filename unknown>:0
>>> E/mono ( 2699): at Android.Views.ISurfaceHolderInvoker.AddCallback
>>> (ISurfaceHolderCallback callback) [0x00000] in<filename unknown>:0
>>> E/mono ( 2699): at ReachMobileCC.PictureActivity.OnResume ()
>>> [0x00000]
>>> in<filename unknown>:0
>>> E/mono ( 2699): at Android.App.Activity.n_OnResume (IntPtr jnienv,
>>> IntPtr native__this) [0x00000] in<filename unknown>:0
>>> E/mono ( 2699): at (wrapper dynamic-method)
>>> object:38c0d09b-61f8-491e-b367-fbed8a6fb14a (intptr,intptr)
>>> I/ActivityManager( 146): Process uk.co.reach.reachcloud (pid 2699) has
>>> died.
>>>
>>> This is the activity class:
>>>
>>> using System;
>>> using System.Collections.Generic;
>>> using System.Linq;
>>> using System.Text;
>>>
>>> using Android.App;
>>> using Android.Content;
>>> using Android.Hardware;
>>> using Android.OS;
>>> using Android.Runtime;
>>> using Android.Views;
>>> using Android.Widget;
>>> using Android.Util;
>>>
>>> namespace ReachMobileCC
>>> {
>>> [Activity(Label = "@string/TakePicture", ConfigurationChanges =
>>> Android.Content.PM.ConfigChanges.Orientation |
>>> Android.Content.PM.ConfigChanges.Keyboard |
>>> Android.Content.PM.ConfigChanges.KeyboardHidden)]
>>> public class PictureActivity : Activity, ISurfaceHolderCallback,
>>> Camera.IPictureCallback
>>> {
>>> #region Fields
>>>
>>> private bool _previewing = false;
>>> private Camera _camera = null;
>>>
>>> #endregion
>>>
>>> public static byte[] JpegData { get; set; }
>>>
>>> #region Event Handlers
>>>
>>> protected override void OnCreate(Bundle bundle)
>>> {
>>> base.OnCreate(bundle);
>>> SetContentView(Resource.Layout.Picture);
>>> FindViewById<Button>(Resource.Id.TakePicture).Click +=
>>> TakePictureClick;
>>> }
>>>
>>> protected override void OnResume()
>>> {
>>> base.OnResume();
>>> var holder =
>>> FindViewById<SurfaceView>(Resource.Id.PicturePreview).Holder;
>>> Log.Info("CameraView", "Adding Callback");
>>> holder.AddCallback(this);
>>> Log.Info("CameraView", "Added Callback");
>>> holder.SetType(SurfaceType.PushBuffers);
>>> }
>>>
>>> public override bool OnKeyDown(Keycode keyCode, KeyEvent e)
>>> {
>>> if (keyCode == Keycode.Back&& _previewing)
>>> {
>>> StopPreviewAndExit(false);
>>> return true;
>>> }
>>> if ((keyCode == Keycode.Camera || keyCode ==
>>> Keycode.DpadCenter)
>>> && _previewing)
>>> {
>>> TakePictureClick(this, new EventArgs());
>>> return true;
>>> }
>>> return base.OnKeyDown(keyCode, e);
>>> }
>>>
>>> void TakePictureClick(object sender, EventArgs e)
>>> {
>>> if (_camera != null)
>>> _camera.TakePicture(null, null, this);
>>> }
>>>
>>> #endregion
>>>
>>> #region ISurfaceHolderCallback Members
>>>
>>> public void SurfaceChanged(ISurfaceHolder holder, int format,
>>> int
>>> width, int height)
>>> {
>>> if (_camera != null)
>>> {
>>> if (_previewing) _camera.StopPreview();
>>> var parameters = _camera.GetParameters();
>>> var previewSize =
>>> GetNearestPreviewSize(parameters.SupportedPreviewSizes, width, height);
>>> parameters.SetPreviewSize(previewSize.Width,
>>> previewSize.Height);
>>> if
>>> (parameters.SupportedFocusModes.Contains(Camera.Parameters.FocusModeAuto))
>>> parameters.FocusMode =
>>> Camera.Parameters.FocusModeAuto;
>>> else if
>>> (parameters.SupportedFocusModes.Contains(Camera.Parameters.FocusModeInfinity))
>>> parameters.FocusMode =
>>> Camera.Parameters.FocusModeInfinity;
>>> parameters.SetRotation(90); // TODO: Match to window
>>> orientation.
>>> _camera.SetParameters(parameters);
>>> _camera.SetPreviewDisplay(holder);
>>> _camera.StartPreview();
>>> _previewing = true;
>>> }
>>> }
>>>
>>> public void SurfaceCreated(ISurfaceHolder holder)
>>> {
>>> _camera = Android.Hardware.Camera.Open();
>>> }
>>>
>>> public void SurfaceDestroyed(ISurfaceHolder holder)
>>> {
>>> StopPreview();
>>> }
>>>
>>> #endregion
>>>
>>> #region IPictureCallback Members
>>>
>>> public void OnPictureTaken(byte[] data, Android.Hardware.Camera
>>> camera)
>>> {
>>> JpegData = data;
>>> StopPreviewAndExit(true);
>>> }
>>>
>>> #endregion
>>>
>>> #region Helper Methods
>>>
>>> private Camera.Size GetNearestPreviewSize(IList<Camera.Size>
>>> sizes,
>>> int width, int height)
>>> {
>>> Camera.Size nearestSize = sizes[0];
>>> int diff = 99999;
>>> foreach (var size in sizes)
>>> {
>>> if (size.Width> width || size.Height> height)
>>> continue;
>>> var comp = (width - size.Width) + (height -
>>> size.Height);
>>> if (comp< diff)
>>> {
>>> comp = diff;
>>> nearestSize = size;
>>> }
>>> }
>>> return nearestSize;
>>> }
>>>
>>> public void StopPreview()
>>> {
>>> if (_camera != null)
>>> {
>>> _camera.StopPreview();
>>> _camera.Release();
>>> _camera = null;
>>> }
>>> }
>>>
>>> public void StopPreviewAndExit(bool ok)
>>> {
>>> StopPreview();
>>> SetResult(ok ? Result.Ok : Result.Canceled, new
>>> Intent(this.ApplicationContext, typeof(PictureActivity)));
>>> Finish();
>>> }
>>>
>>> #endregion
>>> }
>>> }
>>>
>>> This is the layout:
>>>
>>> <?xml version="1.0" encoding="utf-8"?>
>>> <RelativeLayout
>>> xmlns:android="http://schemas.android.com/apk/res/android";
>>> android:layout_width="fill_parent"
>>> android:layout_height="fill_parent">
>>> <Button
>>> android:id="@+id/TakePicture"
>>> android:layout_width="fill_parent"
>>> android:layout_height="wrap_content"
>>> android:text="@string/TakePicture"
>>> android:layout_alignParentBottom="true"
>>> />
>>> <SurfaceView
>>> android:id="@+id/PicturePreview"
>>> android:layout_width="fill_parent"
>>> android:layout_height="fill_parent"
>>> android:layout_above="@id/TakePicture"
>>> />
>>> </RelativeLayout>
>>>
>>>
>>> --
>>> View this message in context:
>>> http://mono-for-android.1047100.n5.nabble.com/SurfaceHolder-AddCallback-random-errors-tp4669293p4678027.html
>>> Sent from the Mono for Android mailing list archive at Nabble.com.
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>>>
>>>
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>
> --
> View this message in context:
> http://mono-for-android.1047100.n5.nabble.com/SurfaceHolder-AddCallback-random-errors-tp4669293p4681127.html
> Sent from the Mono for Android mailing list archive at Nabble.com.
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