Android图像缓存内存异步问题

Question

我正在使用图像加载器类来加载和捕获图像，但我遇到了内存大小的问题以及它引发的logcat消息，如下所示，直到我的应用程序冻结执行，我不明白为什么会发生这种情况？

10-11 14:11:22.735: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.735: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.745: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.755: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.755: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.765: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.775: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.775: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.784: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.795: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.795: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.806: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.814: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.814: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.824: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.824: I/MemoryCache(859): MemoryCache will use up to 125.0MB
10-11 14:11:22.834: I/MemoryCache(859): MemoryCache will use up to 125.0MB

这是我的内存捕获类

 public class MemoryCache {

    private static final String TAG = "MemoryCache";
    private Map<String, Bitmap> cache=Collections.synchronizedMap(
            new LinkedHashMap<String, Bitmap>(10,1.5f,true));//Last argument true for LRU ordering
    private long size=0;//current allocated size
    private long limit=1000000;//max memory in bytes

    public MemoryCache(){

        //use 25% of available heap size
        setLimit(Runtime.getRuntime().maxMemory()/4);
        //setLimit(Runtime.getRuntime().maxMemory()/4);
    }

    public void setLimit(long new_limit){
        limit=new_limit;

        Log.i(TAG, "MemoryCache will use up to "+limit/1024./1024.+"MB");
    }

    public Bitmap get(String id){
        try{
            if(!cache.containsKey(id))
                return null;
            //NullPointerException sometimes happen here http://code.google.com/p/osmdroid/issues/detail?id=78 

            return cache.get(id);
        }catch(NullPointerException ex){
            ex.printStackTrace();
            return null;
        }
    }

    public void put(String id, Bitmap bitmap){
        try{
            if(cache.containsKey(id))
                size-=getSizeInBytes(cache.get(id));
            cache.put(id, bitmap);
            size+=getSizeInBytes(bitmap);
            checkSize();
        }catch(Throwable th){
            th.printStackTrace();
        }
    }

    private void checkSize() {
        Log.i(TAG, "cache size="+size+" length="+cache.size());
        if(size>limit){
            Iterator<Entry<String, Bitmap>> iter=cache.entrySet().iterator();//least recently accessed item will be the first one iterated  
            while(iter.hasNext()){
                Entry<String, Bitmap> entry=iter.next();
                size-=getSizeInBytes(entry.getValue());
                iter.remove();
                if(size<=limit)
                    break;
            }
            Log.i(TAG, "Clean cache. New size "+cache.size());
        }
    }

    public void clear() {
        try{
            //NullPointerException sometimes happen here http://code.google.com/p/osmdroid/issues/detail?id=78 
            cache.clear();
            size=0;
        }catch(NullPointerException ex){
            ex.printStackTrace();
        }
    }

    long getSizeInBytes(Bitmap bitmap) {
        if(bitmap==null)
            return 0;
        return bitmap.getRowBytes() * bitmap.getHeight();
    }
}

我正在使用异步任务机制在列表视图中调用此图像，您的帮助将对我非常有用，谢谢

Answer 1

为什么Log.i(TAG, "MemoryCache will use up to "+limit/1024./1024.+"MB");会被调用这么多次？请检查您是否一直在创建MemoryCache实例，还是多次在某个地方调用setLimit。