项目用到加载大图片，app老是出现OOM异常，总结了几点经验，供参考。
1、手动干涉dalvik的堆内存处理效率：
1 private final static float TARGET_HEAP_UTILIZATION = 0.75f;
2 //for same activity
3 public void onCreate()
4 {
5 …………
6 VMRuntime.getRuntime().setTargetHeapUtilization(TARGET_HEAP_UTILIZATION);
7 …………
8 }
2、手动指定Android堆大小：
1 private final static int CWJ_HEAP_SIZE = 6* 1024* 1024 ;
2 //for same activity
3 public void onCreate()
4 {
5 …………
6 VMRuntime.getRuntime().setMinimumHeapSize(CWJ_HEAP_SIZE); //设置最小heap内存为6MB大小。当然对于内存吃紧来说还可以通过手动干涉GC去处理
7 …………
8 }
3、手动指定回收内存，指定gc：
1 if(bitmap!=null && !bitmap.isRecycled())
2 {
3 bitmap.recycle();
4 System.gc();
5 }
4、图片必须进行缩放，不然多半会出OOM：
1 /**
2 * @param url
3 * 图片的url
4 * @param sc
5 * ，显示的像素大小
6 * @return 返回指定RUL的缩略图
7 *
8 * @author jevan 2012-7-3
9 *
10 */
11 public static Bitmap loadImageFromUrl(String url, int sc)
12 {
13
14 URL m;
15 InputStream i = null;
16 BufferedInputStream bis = null;
17 ByteArrayOutputStream out = null;
18
19 if (url == null)
20 return null;
21 try
22 {
23 m = new URL(url);
24 i = (InputStream) m.getContent();
25 bis = new BufferedInputStream(i, 1024 * 4);
26 out = new ByteArrayOutputStream();
27 int len = 0;
28
29 while ((len = bis.read(isBuffer)) != -1)
30 {
31 out.write(isBuffer, 0, len);
32 }
33 out.close();
34 bis.close();
35 } catch (MalformedURLException e1)
36 {
37 e1.printStackTrace();
38 return null;
39 } catch (IOException e)
40 {
41 e.printStackTrace();
42 }
43 if (out == null)
44 return null;
45 byte[] data = out.toByteArray();
46 BitmapFactory.Options options = new BitmapFactory.Options();
47 options.inJustDecodeBounds = true;
48 BitmapFactory.decodeByteArray(data, 0, data.length, options);
49 options.inJustDecodeBounds = false;
50 int be = (int) (options.outHeight / (float) sc);
51 if (be <= 0)
52 {
53 be = 1;
54 } else if (be > 3)
55 {
56 be = 3;
57 }
58 options.inSampleSize = be;
59 Bitmap bmp =null;
60 try
61 {
62 bmp = BitmapFactory.decodeByteArray(data, 0, data.length, options); //返回缩略图
63 } catch (OutOfMemoryError e)
64 {
65 // TODO: handle exception
66 MainActivity.print("Tile Loader (241) Out Of Memory Error " + e.getLocalizedMessage());
67
68 System.gc();
69 bmp =null;
70 }
71 return bmp;
72 }
把上面几条全部用上，OOM的异常基本上能完全避免！！！