Question

我正试图找出多年来为什么我在listview的视图中出现了这个内存泄漏。

奇怪的是，当使用（（BitmapDrawable）_activity.Resources.GetDrawable（Resource.Drawable.splash））。Bitmap设置imageview（coverIv）时，根本没有问题。

当我使用await ImageLoader.DecodeSampledBitmapFromResourceAsync（localImageLocation，imgWidth，imgHeight）时，每次在listview中滚动一点时都会出现巨大的内存泄漏

我尝试使用内存分析器工具查找引用但没有...虽然MAT说问题是位图

public void ImageLoaded(string localImageLocation)
{
            int screenWidth = _activity.Resources.DisplayMetrics.WidthPixels;
            int imgWidth = screenWidth - (int)ConvertDpToPix (32f);
            int imgHeight = (int)(ConvertDpToPix(206f));

            BundleProgress.Visibility = ViewStates.Gone;

            if (CoverIv.Drawable != null)
            {
                            ((BitmapDrawable)CoverIv.Drawable).Bitmap.Recycle ();
                            ((BitmapDrawable)CoverIv.Drawable).Bitmap.Dispose ();
                            CoverIv.SetImageDrawable (null);
            }

            CoverIv.SetImageBitmap 
            (

            //MEMORYLEAK:   await ImageLoader.DecodeSampledBitmapFromResourceAsync  (localImageLocation, imgWidth, imgHeight)
                ((BitmapDrawable)_activity.Resources.GetDrawable(Resource.Drawable.splash)).Bitmap
            );

ImageLoader类中的方法：

        public static async Task<Bitmap> DecodeSampledBitmapFromResourceAsync (String path,int reqWidth, int reqHeight)
            {

            // First decode with inJustDecodeBounds=true to check dimensions of the image
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.InJustDecodeBounds = true;
            Bitmap bitmap = await BitmapFactory.DecodeFileAsync(path, options);

            // Calculate inSampleSize
            options.InSampleSize = CalculateInSampleSize(options, reqWidth,
                reqHeight);

            // Decode bitmap with inSampleSize set
            options.InJustDecodeBounds = false;
            options.InPreferredConfig = Bitmap.Config.Argb8888;
            //options.InDither = true;

            return await BitmapFactory.DecodeFileAsync(path, options);
        }

      public static int CalculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight)
        {
            // Raw height and width of image
            float height = options.OutHeight;
            float width = options.OutWidth;
            double inSampleSize = 1D;

            if (height > reqHeight || width > reqWidth)
            {
                int halfHeight = (int)(height / 2);
                int halfWidth = (int)(width / 2);

                // Calculate a inSampleSize that is a power of 2 - the decoder will use a value that is a power of two anyway.
                while ((halfHeight / inSampleSize) > reqHeight && (halfWidth / inSampleSize) > reqWidth)
                {
                    inSampleSize *= 2;
                }
            }

            return (int)inSampleSize;
        }

适配器：

public override View GetView (int position, View convertView, ViewGroup parent)
    {
        BaseBundelVO bundle = _bundles [position];

        DSBundleListItem bundleHolder = null;
        DSBundleArchiveItem archiveHolder = null;

        int type = GetItemViewType(position);
        if (convertView == null)
        {
            bundleHolder = new DSBundleListItem (_activity.ApplicationContext);
            archiveHolder = new DSBundleArchiveItem (_activity.ApplicationContext);

            switch (type) 
            {
            case 0:
                convertView = _activity.LayoutInflater.Inflate (Resource.Layout.dsBundleListItem, null);
                bundleHolder.IconIv = convertView.FindViewById<ImageView> (Resource.Id.iconIv);
                bundleHolder.CoverIv = convertView.FindViewById<ImageView> (Resource.Id.coverIv);
                bundleHolder.CoverTitleTv = convertView.FindViewById<TextView> (Resource.Id.coverTitleTv);
                bundleHolder.CoverSubTitleTv = convertView.FindViewById<TextView> (Resource.Id.coverSubTitleTv);
                bundleHolder.BundleProgress = convertView.FindViewById<ProgressBar> (Resource.Id.bundleProgress);
                convertView.Tag = bundleHolder;
                break;

            case 1:
                convertView = _activity.LayoutInflater.Inflate (Resource.Layout.dsBundleArchiveItem, null);
                archiveHolder.ArchiveTitleTv = convertView.FindViewById<TextView> (Resource.Id.archiveTitleTv);
                archiveHolder.ArchiveSubTitleTv = convertView.FindViewById<TextView> (Resource.Id.archiveSubTitleTv);
                convertView.Tag = archiveHolder;
                break;

            }

        } 
        else 
        {
            switch (type) 
            {
            case 0:
                bundleHolder = (DSBundleListItem)convertView.Tag;
            break;

            case 1:
                archiveHolder = (DSBundleArchiveItem)convertView.Tag;
            break;

            }
        }

        switch (type) 
        {
        case 0:
            bundleHolder.CoverTitleTv.Text = bundle.Title;
            bundleHolder.CoverSubTitleTv.Text = bundle.SubTitle;

            bundleHolder.CoverIv.SetImageDrawable (null);
            bundleHolder.IconIv.SetImageDrawable (null);

            bundleHolder.LoadImage(bundle.CoverImageLocation,bundle.Icon);
            break;

        case 1:
            archiveHolder.ArchiveTitleTv.Text    = "Archief";
            archiveHolder.ArchiveSubTitleTv.Text = "Bekijk onze eerder verschenen publicaties";
            break;

        }

        return convertView;
    }

    public void SetData(List<BaseBundelVO> bundles)
    {
        _bundles.Clear ();
        _bundles.AddRange(bundles);
    }

Answer 1

使用图片时使用the picasso library，它可以创造奇迹！

Answer 2

我也推荐Pisasso图书馆。这是链接：http://square.github.io/picasso/

它立即从网上检索图像并在本地缓存它。

导入Picasso库后，您只需将此行添加到代码中：

Picasso.with(context).load("*your url*").into(*your image view*);

您也可以加载本地图像！

Picasso.with(context).load("file:///android_asset/image.png").into(*your image view*);

希望这会有所帮助，

Answer 3

请尝试我的代码。我认为你的解码有问题：

private Bitmap DisplayRotatedPhoto(Uri path) {
    String filePath = path.toString().substring(8);
    Bitmap oriented = null;
    BitmapFactory.Options bitmapFactoryOptions = new BitmapFactory.Options();
    bitmapFactoryOptions.inJustDecodeBounds = true;

    int REQUIRED_SIZE = 100;
    int width_tmp = bitmapFactoryOptions.outWidth, height_tmp = bitmapFactoryOptions.outHeight;
    int scale = 2;
    while (true) {
        if (width_tmp / 2 < REQUIRED_SIZE || height_tmp / 2 < REQUIRED_SIZE)
            break;
        width_tmp /= 2;
        height_tmp /= 2;
        scale++;
      }
    BitmapFactory.Options bitmapFactoryOptions2 = new BitmapFactory.Options();
    bitmapFactoryOptions2.inSampleSize = scale;
    Bitmap bmp = BitmapFactory.decodeFile(filePath, bitmapFactoryOptions2);
}

从视图中的路径加载位图时内存泄漏

3 个答案: