java.lang.RuntimeException:在Android中执行doInBackground()时出错

Question

我正在开发一个应用程序，用户出售或购买二手物品。在我的第一个活动中，我有网格视图，在这里我显示缩略图，当用户单击图像时，它会带他进行详细的活动。我使用后退按钮返回到主活动页面。它可以正常工作，但如果我点击8-9图像并退出内存(OOM)，就会崩溃。

CustomVolleyRequest类

public class CustomVolleyRequest {

    private static CustomVolleyRequest customVolleyRequest;
    private static Context context;
    private RequestQueue requestQueue;
    private ImageLoader imageLoader;


    private CustomVolleyRequest(Context context) {
        this.context = context;
        this.requestQueue = getRequestQueue();

        imageLoader = new ImageLoader(requestQueue,
                new ImageLoader.ImageCache() {
                    private final LruCache<String, Bitmap>
                            cache = new LruCache<String, Bitmap>(20);

                    @Override
                    public Bitmap getBitmap(String url) {
                        return cache.get(url);
                    }

                    @Override
                    public void putBitmap(String url, Bitmap bitmap) {
                        cache.put(url, bitmap);
                    }
                });
    }

    public static synchronized CustomVolleyRequest getInstance(Context context) {
        if (customVolleyRequest == null) {
            customVolleyRequest = new CustomVolleyRequest(context);
        }
        return customVolleyRequest;
    }

    public RequestQueue getRequestQueue() {
        if (requestQueue == null) {
            Cache cache = new DiskBasedCache(context.getCacheDir(), 10 * 1024 * 1024);
            Network network = new BasicNetwork(new HurlStack());
            requestQueue = new RequestQueue(cache, network);
            requestQueue.start();
        }
        return requestQueue;
    }

    public ImageLoader getImageLoader() {
        return imageLoader;
    }

}

内存监控，每次点击递增，当我返回主活动时，它会释放内存！

​

​

堆栈跟踪：

E/AndroidRuntime: FATAL EXCEPTION: AsyncTask  E/AndroidRuntime: 
Process: PID: 5700 
java.lang.RuntimeException: An error occured while executing
doInBackground()  E/AndroidRuntime:     at
android.os.AsyncTask$3.done(AsyncTask.java:300)  E/AndroidRuntime:     at
java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
E/AndroidRuntime:     at
java.util.concurrent.FutureTask.setException(FutureTask.java:222)
E/AndroidRuntime:     at
java.util.concurrent.FutureTask.run(FutureTask.java:242)
E/AndroidRuntime:     at
android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
E/AndroidRuntime:     at
 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
E/AndroidRuntime:     at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
E/AndroidRuntime:     at java.lang.Thread.run(Thread.java:841) 
E/AndroidRuntime:  Caused by: java.lang.OutOfMemoryError
E/AndroidRuntime:     at
android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
E/AndroidRuntime:     at
android.graphics.BitmapFactory.decodeStreamInternal(BitmapFactory.java:613)
E/AndroidRuntime:     at
android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:589)
E/AndroidRuntime:     at
android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:627)
E/AndroidRuntime:     at
 com.example.xxx.xxx.DownloadImageTask.doInBackground(DownloadImageTask.java:26)
E/AndroidRuntime:     at
 com.example.xxx.xxx.DownloadImageTask.doInBackground(DownloadImageTask.java:14)
E/AndroidRuntime:     at
android.os.AsyncTask$2.call(AsyncTask.java:288)
E/AndroidRuntime:     at
java.util.concurrent.FutureTask.run(FutureTask.java:237)
E/AndroidRuntime:     at
android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
E/AndroidRuntime:     at
 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 
E/AndroidRuntime:     at
 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) 
E/AndroidRuntime:     at java.lang.Thread.run(Thread.java:841)

Answer 1

根据日志，请查看这一行：

E/AndroidRuntime:  Caused by: java.lang.OutOfMemoryError

它清楚地说，应用程序崩溃仅仅是因为OutOfMemoryError异常。一个可能的原因可能是你正在处理大尺寸的位图而没有缩小它们。在将位图设置为图像视图之前，您需要调整其大小和缩小位图的大小。

有关如何有效管理位图的详细信息，请参阅正式的文档