我所知道的问题是在具有16 MB堆内存的设备中，我需要解决它。我有线程从服务器（大图像）获取图像并缓存然后显示。问题是我的内存不足。为了进一步解释，我发布了我的日志猫以及一些代码：
public class Test extends Activity implements OnClickListener {
ImageView paint, wheels, shadow;
Button b;
int j = 2;
int i = 1;
String pathToWheels, pathToPaint, pathToShadow;
String stringAngle;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
MemoryInfo dbm = new MemoryInfo();
Debug.getMemoryInfo(dbm);
b = (Button) findViewById(R.id.button1);
b.setOnClickListener(this);
wheels = (ImageView) findViewById(R.id.imageView3);
paint = (ImageView) findViewById(R.id.imageView2);
shadow = (ImageView) findViewById(R.id.imageView1);
while (i < 13) {
stringAngle = Integer.toString(i);
String pathToWheels = url;
String pathToPaint = url;
String pathToShadow = url;
if (Cache.getCacheFile(pathToWheels) == null) {
ImageDownloader downloader1 = new ImageDownloader(wheels);
downloader1
.execute(url);
} else if (Cache.getCacheFile(pathToShadow) == null) {
ImageDownloader downloader2 = new ImageDownloader(shadow);
downloader2
.execute(url);
} else if (Cache.getCacheFile(pathToPaint) == null) {
ImageDownloader downloader = new ImageDownloader(paint);
downloader
.execute(url);
}
i++;
}
}
@Override
protected void onPause() {
super.onPause();
Toast.makeText(getApplicationContext(),"Pause",
Toast.LENGTH_SHORT).show();
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.button1) {
if (j == 13)
{
j = 1;
}
String s = Integer.toString(j);
wheels.setImageBitmap(Cache
.getCacheFile(url));
paint.setImageBitmap(Cache
.getCacheFile(url));
shadow.setImageBitmap(Cache
.getCacheFile(url));
j++;
}
}
}
从我的缓存类：
public static void saveCacheFile(String cacheUri, Bitmap image) {
if(!isCacheWritable()) return;
Log.i("CACHE S",cacheUri);
cache.saveCacheFile(cacheUri, image);
来自我的CacheStore类：
public Bitmap getCacheFile(String cacheUri) {
if(bitmapMap.containsKey(cacheUri)) return (Bitmap)bitmapMap.get(cacheUri);
if(!cacheMap.containsKey(cacheUri)) return null;
String fileLocalName = cacheMap.get(cacheUri);
File fullCacheDir = new File(Environment.getExternalStorageDirectory().toString(),cacheDir);
File fileUri = new File(fullCacheDir.toString(), fileLocalName);
if(!fileUri.exists()) return null;
Log.i("CACHE", "File "+cacheUri+" has been found in the Cache");
Bitmap bm = BitmapFactory.decodeFile(fileUri.toString());
Bitmap.createScaledBitmap(bm, 480, 320, true);
bitmapMap.put(cacheUri, bm);
return bm;
}
应用程序在此行崩溃：位图bm = BitmapFactory.decodeFile（fileUri.toString（））; 我的内存耗尽。
我的logcat：
07-06 23:40:20.720: ERROR/dalvikvm-heap(1844): 691200-byte external allocation too large for this process.
07-06 23:40:20.720: ERROR/GraphicsJNI(1844): VM won't let us allocate 691200 bytes
07-06 23:40:20.770: DEBUG/skia(1844): --- decoder->decode returned false
07-06 23:40:20.790: DEBUG/AndroidRuntime(1844): Shutting down VM
07-06 23:40:20.830: WARN/dalvikvm(1844): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): FATAL EXCEPTION: main
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): java.lang.OutOfMemoryError: bitmap size exceeds VM budget
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:459)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:271)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:296)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at com.cache.CacheStore.getCacheFile(CacheStore.java:117)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at com.cache.Cache.getCacheFile(Cache.java:38)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at com.cache.Test.onClick(Test.java:118)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.view.View.performClick(View.java:2408)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.view.View$PerformClick.run(View.java:8816)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.os.Handler.handleCallback(Handler.java:587)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.os.Handler.dispatchMessage(Handler.java:92)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.os.Looper.loop(Looper.java:123)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.app.ActivityThread.main(ActivityThread.java:4627)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at java.lang.reflect.Method.invokeNative(Native Method)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at java.lang.reflect.Method.invoke(Method.java:521)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at dalvik.system.NativeStart.main(Native Method)
非常感谢任何帮助，感谢您的阅读。
答案 0 :(得分：2)
您需要重新设置并缩放位图之前，以便将它们插入到imagedownloader内的缓存中。
过去，我必须在从网上下载之前检测图像的文件大小。如果它太大我只使用默认图像。
此外，我还通过调整BitmapFactory采样大小来降低保存图像的分辨率，并调整应用中最终图像的大小。 （这为缓存节省了大量空间。）
请参阅How to know the size of a file before downloading it?
//somewhere inside image downloader class...
{...}
BitmapFactory.Options options = new BitmapFactory.Options();
if(enableSampling)
options.inSampleSize = 2;
returnBitmap = BitmapFactory.decodeStream(is, null, options);
if(returnBitmap != null)
{
if(scaleImage)
returnBitmap = Bitmap.createScaledBitmap(returnBitmap, width, height, true);
// insert the image into the cache
imageCache.put(url, new SoftReference<Bitmap>(returnBitmap));
// Check the ImageView for nulls
if(imageView != null && callback != null){
ImageDisplayer displayer = new ImageDisplayer(imageView, returnBitmap, parentView, tag);
callback.onImageReceived(displayer);
}
}
{...}
到目前为止，这对我有用，并且对INSANE文件大小的检查已经使应用程序在多种情况下都不会崩溃，更不用说它可以在后台跳过下载大量文件了。
答案 1 :(得分：1)