第三次从图库中选择图像时内存不足

Question

I have a app need to load large images (2mb) for serveral times from the gallery and show in an imageview. I want to allow user to change the image after they select. So they can get back to previous activity and select again. This works fine for the first two times, however, on the third time, it crush for out of memory.

[dalvikvm-heap] Out of memory on a 32741392-byte allocation.

[BitmapFactory] decoder JPEG decode fail!

[skia] --- decoder->decode returned false

protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
    {

        if ((requestCode == PickImageId) && (resultCode == Result.Ok) && (data != null)) 
        {
            uri = data.Data;
            _paintView.SetImageURI (uri);

            string path = GetPathToImage (uri);
            Toast.MakeText (this, path, ToastLength.Long);
        }

        if (uri != null) {

            //at the third time crush at this line
            _paintView._Bmp= Android.Provider.MediaStore.Images.Media.GetBitmap(this.ContentResolver, uri);       

            _paintView._Bmp= _paintView._Bmp.Copy(Android.Graphics.Bitmap.Config.Argb8888, true);

            _paintView._Bmp=Bitmap.CreateScaledBitmap(_paintView._Bmp, _paintView.w, _paintView.h, false);
            _paintView._Canvas = new Canvas(_paintView._Bmp);
            _paintView.SetImageBitmap (_paintView._Bmp);

            uri.Dispose ();

            _paintView2.SetImageBitmap (null);

            _bitmap = _paintView._Bmp;
        }

    }

So I add a bitmap recycle at the OnBackPressed() and want to free the memory this activity consuming

public override void OnBackPressed ()
    {
        base.OnBackPressed(); 

        //_paintView._Bmp and _paintView2._Bmp contain the bitmap I use

        if (_paintView._Bmp != null) {
            _paintView._Bmp.Recycle ();
            _paintView._Bmp = null;
        }

        if (_paintView2._Bmp != null) {
            _paintView2._Bmp.Recycle ();
            _paintView2._Bmp = null;
        }

        base.OnDestroy ();

        StartActivity(new Intent(this, typeof(MainActivity)));
        Finish();
    }

However, it still doesn't work. I just basically don't want to resize the bitmap, since I will do some image processing stuff and low quality will make it looks bad. So how can I free the memory after I use?

The first time successfully load

[skia] jpeg_decoder mode 1, config 6, w 3504, h 2336, sample 1, bsLength 0!!

[dalvikvm-heap] Grow heap (frag case) to 37.557MB for 32741392-byte allocation

[skia] jpeg_decoder finish successfully, L:1881!!!

[ManageCursor] managedQuery, c=1108461336

[ManageCursor] startManagingCursor, c=1108461336

[skia] jpeg_decoder mode 1, config 6, w 3504, h 2336, sample 1, bsLength 0!!

[dalvikvm-heap] Grow heap (frag case) to 68.783MB for 32741392-byte allocation

[skia] jpeg_decoder finish successfully, L:1881!!!

Is this mean I use too much memory for select one image? Should I resize bitmap or free memory? Thank yous very much!

Answer 1

You're image is to big. You should load it in a smaller size because a Bitmap takes up 4 bytes for a pixels. So a 5MP image, will result in 20MB of memory.

You need to load in the Bitmap's meta data, recalculate the required sample size, and request the Bitmap in that size. This can be done with Bitmap.Options . Read all about it in the Developer guide. http://developer.android.com/training/displaying-bitmaps/load-bitmap.html