有效加载位图 - 仍然出现内存不足错误

Question

加载自定义图像时出现内存不足错误。我阅读了https://developer.android.com/training/displaying-bitmaps/load-bitmap.html 寻求帮助。

我正在按照示例对流进行解码以首先获取大小信息，然后再进行解码。仍然在第一次解码时崩溃。有没有办法解决这个问题？

ava.lang.OutOfMemoryError：无法分配 48771084 字节分配，其中 16776928 个可用字节和 25MB 直到 OOM BackgroundImageManager.java，第 84 行

dalvik.system.VMRuntime.newNonMovableArray 原生方法 2 android.graphics.BitmapFactory.nativeDecodeStream 原生方法 3 android.graphics.BitmapFactory.decodeStreamInternal BitmapFactory.java，第 882 行 4 android.graphics.BitmapFactory.decodeStream BitmapFactory.java，第 858 行 5 android.graphics.BitmapFactory.decodeStream BitmapFactory.java，第 896 行 6 com.myapp.Utils.BackgroundImageManager.background BackgroundImageManager.java，第 8 行

public class BackgroundImageManager {
    private final static String TAG = BackgroundImageManager.class.getSimpleName();
    private static InputStream currentBackgroundImage;

    public static int calculateInSampleSize(
            BitmapFactory.Options options, int reqWidth, int reqHeight) {
        // Raw height and width of image
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {

            final int halfHeight = height / 2;
            final int halfWidth = width / 2;

            // Calculate the largest inSampleSize value that is a power of 2 and keeps both
            // height and width larger than the requested height and width.
            while ((halfHeight / inSampleSize) >= reqHeight
                    && (halfWidth / inSampleSize) >= reqWidth) {
                inSampleSize *= 2;
            }
        }
        Log.v("Biscuit-Sample", String.valueOf(inSampleSize));
        if (inSampleSize < 4) {
            inSampleSize = 4;
        }
        return inSampleSize;
    }

    public static Drawable background(Context context, Store store) {
        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);

        String bgUri = null;
        int bgId = 0;
        if (store != null) {
            bgUri = store.backgroundImageURI;
            bgId = store.backgroundImageNumber;
        }

        if (currentBackgroundImage != null) {
            try {
                currentBackgroundImage.close();
                Log.v(TAG, "Current background image closed.");
            } catch (IOException e) {
                Log.e(TAG, "Could not close background image.", e);
            }
        }

        if(bgUri != null && !bgUri.isEmpty()) {
            try {
                BitmapFactory.Options options = new BitmapFactory.Options();
                options.inJustDecodeBounds = true;

                Activity activity = (Activity) context;
                Display display = activity.getWindowManager().getDefaultDisplay();
                Point size = new Point();
                display.getSize(size);
                int width = size.x;
                int height = size.y;
                BitmapFactory.decodeStream( context.getContentResolver().openInputStream(Uri.parse(bgUri)) );
                options.inSampleSize = BackgroundImageManager.calculateInSampleSize(options, width, height);
                Bitmap bitmap = BitmapFactory.decodeStream( context.getContentResolver().openInputStream(Uri.parse(bgUri)) );
                Drawable d = new BitmapDrawable(context.getResources(), bitmap);
                return d;
            } catch (FileNotFoundException e) {
                Log.e(TAG, "Custom background image file could not be found.", e);
            } catch (IOException e) {
                Log.e(TAG, "Could not close custom background image after creating drawable", e);
            }
        }
        if(bgId != 0) {
            try {
                return context.getResources().getDrawable(bgId);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return context.getResources().getDrawable(R.drawable.bg_default);
    }

Answer 1

要处理 bitmpas，您可以使用众多可用的开源库之一。例如Fresco

你的问题：

首先，您将同一个位图解码两次。

BitmapFactory.decodeStream( context.getContentResolver().openInputStream(Uri.parse(bgUri)) );
options.inSampleSize = BackgroundImageManager.calculateInSampleSize(options, width, height);
Bitmap bitmap = BitmapFactory.decodeStream( context.getContentResolver().openInputStream(Uri.parse(bgUri)) );

这可能是错误的复制/粘贴。在第一行中，位图被解码并且未被使用。删除第一个BitmapFactory.decodeStream

问题出在这里

Bitmap bitmap = BitmapFactory.decodeStream( context.getContentResolver().openInputStream(Uri.parse(bgUri)) );

应该是

Bitmap bitmap = BitmapFactory.decodeStream( context.getContentResolver().openInputStream(Uri.parse(bgUri)), null, options);

选项的对象必须是方法调用的一部分才能使用。

Answer 2

更好的图像管理方法是使用 Picasso 库，因为它管理缓存和内存，因此可以避免 OutOfMemory 崩溃。

示例：Picasso.with(Context).load("your_url").into(yourImageView);

更多信息在这里： Picasso library