字节分配内存不足，异步任务 5

Question

我正在尝试从“url”加载图像，该文件夹是我的 SD 卡中包含大约 40 张图像的文件夹到我的阅读器中，但我不断收到内存不足错误。有没有办法解决它？可能是因为我试图一次加载 40 张图片，这就是导致错误的原因吗？

下面是我的 logcat 输出

02-01 15:38:17.410: D/url(10695): /mnt/sdcard/Android/data/com.sfa.coverflow/Issues/20/1944628064
02-01 15:38:17.440: D/dalvikvm(10695): GC_FOR_ALLOC freed 7144K, 32% free 16978K/24711K, paused 23ms
02-01 15:38:17.440: I/dalvikvm-heap(10695): Forcing collection of SoftReferences for 33033616-byte allocation
02-01 15:38:17.460: D/dalvikvm(10695): GC_BEFORE_OOM freed 9K, 32% free 16969K/24711K, paused 25ms
02-01 15:38:17.460: E/dalvikvm-heap(10695): Out of memory on a 33033616-byte allocation.
02-01 15:38:17.460: I/dalvikvm(10695): "AsyncTask #5" prio=5 tid=17 RUNNABLE
02-01 15:38:17.460: I/dalvikvm(10695):   | group="main" sCount=0 dsCount=0 obj=0x411358f0 self=0x468d20
02-01 15:38:17.460: I/dalvikvm(10695):   | sysTid=10718 nice=10 sched=0/0 cgrp=bg_non_interactive handle=3779488
02-01 15:38:17.460: I/dalvikvm(10695):   | schedstat=( 48743000 7345000 28 ) utm=4 stm=0 core=1
02-01 15:38:17.460: I/dalvikvm(10695):   at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
02-01 15:38:17.460: I/dalvikvm(10695):   at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:493)
02-01 15:38:17.460: I/dalvikvm(10695):   at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:299)
02-01 15:38:17.460: I/dalvikvm(10695):   at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:324)
02-01 15:38:17.460: I/dalvikvm(10695):   at com.sfa.touchview.UrlTouchImageView$ImageLoadTask.doInBackground(UrlTouchImageView.java:108)
02-01 15:38:17.460: I/dalvikvm(10695):   at com.sfa.touchview.UrlTouchImageView$ImageLoadTask.doInBackground(UrlTouchImageView.java:1)
02-01 15:38:17.460: I/dalvikvm(10695):   at android.os.AsyncTask$2.call(AsyncTask.java:264)
02-01 15:38:17.460: I/dalvikvm(10695):   at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
02-01 15:38:17.460: I/dalvikvm(10695):   at java.util.concurrent.FutureTask.run(FutureTask.java:137)
02-01 15:38:17.460: I/dalvikvm(10695):   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
02-01 15:38:17.460: I/dalvikvm(10695):   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
02-01 15:38:17.460: I/dalvikvm(10695):   at java.lang.Thread.run(Thread.java:856)
02-01 15:38:17.460: D/skia(10695): --- decoder->decode returned false
02-01 15:38:17.470: W/dalvikvm(10695): threadid=17: thread exiting with uncaught exception (group=0x40a4f1f8)
02-01 15:38:17.470: E/AndroidRuntime(10695): FATAL EXCEPTION: AsyncTask #5
02-01 15:38:17.470: E/AndroidRuntime(10695): java.lang.RuntimeException: An error occured while executing doInBackground()
02-01 15:38:17.470: E/AndroidRuntime(10695):    at android.os.AsyncTask$3.done(AsyncTask.java:278)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at java.util.concurrent.FutureTask.run(FutureTask.java:137)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at java.lang.Thread.run(Thread.java:856)
02-01 15:38:17.470: E/AndroidRuntime(10695): Caused by: java.lang.OutOfMemoryError
02-01 15:38:17.470: E/AndroidRuntime(10695):    at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:493)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:299)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:324)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at com.sfa.touchview.UrlTouchImageView$ImageLoadTask.doInBackground(UrlTouchImageView.java:108)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at com.sfa.touchview.UrlTouchImageView$ImageLoadTask.doInBackground(UrlTouchImageView.java:1)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at android.os.AsyncTask$2.call(AsyncTask.java:264)
02-01 15:38:17.470: E/AndroidRuntime(10695):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
02-01 15:38:17.470: E/AndroidRuntime(10695):    ... 4 more

这是发生错误的地方

public class ImageLoadTask extends AsyncTask<String, Integer, Bitmap>
    {
        //RETRIEVES LINK FROM GALLERYACTIVITY
        //READ MNT/SDCARD/....

        @Override
        protected Bitmap doInBackground(String... strings) {
            bm = null;
            String url = strings[0];
            Log.d("url",url);

            bm = BitmapFactory.decodeFile(url);
            return bm;

        }

Answer 1

使用下面的代码调整位图的大小。

例如，如果您在 300 * 300 的视图中加载分辨率为 1200 *800 的图像

您可以使用decodeSampledBitmapFromResource(getResource(),R.drawable.mImage,300,300) 降低内存使用率。

/**
     * 
     * get a resized bitmap
     * @param bm
     * @param newHeight
     * @param newWidth
     * @return
     */
    public static Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {
        int width = bm.getWidth();
        int height = bm.getHeight();
        float scaleWidth = ((float) newWidth) / width;
        float scaleHeight = ((float) newHeight) / height;
        // create a matrix for the manipulation
        Matrix matrix = new Matrix();
        // resize the bitmap
        matrix.postScale(scaleWidth, scaleHeight);
        // "recreate" the new bitmap
        Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height,
                matrix, false);
        return resizedBitmap;
    }

    /**
     * Decode a bitmap for avoiding out of memory issue
     * @param res
     * @param resId
     * @param reqWidth
     * @param reqHeight
     * @return
     */
    public static Bitmap decodeSampledBitmapFromResource(Resources res,
            int resId, int reqWidth, int reqHeight) {

        // First decode with inJustDecodeBounds=true to check dimensions
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeResource(res, resId, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, reqWidth,
                reqHeight);
        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        return BitmapFactory.decodeResource(res, resId, options);

    }

    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) {

            // Calculate ratios of height and width to requested height and
            // width
            final int heightRatio = Math.round((float) height
                    / (float) reqHeight);
            final int widthRatio = Math.round((float) width / (float) reqWidth);

            // Choose the smallest ratio as inSampleSize value, this will
            // guarantee
            // a final image with both dimensions larger than or equal to the
            // requested height and width.
            inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
        }

        return inSampleSize;
    }

Answer 2

你应该this关于加载位图的文章来避免这种情况。观看来自 Android 开发者的 video 也会很有用。