我攻克了oom

BitmapFactory.Options options=new BitmapFactory.Options();
    options.inJustDecodeBounds = false;
    options.inSampleSize = 10;   //width，hight设为原来的十分一

return BitmapFactory.decodeFile(imgPath,options);

options必加上

最后再回收

@Override
protected void onDestroy(){
if(b!=null){
b.recycle();
System.gc();
}
}