android 程式取得剩餘/使用記憶體百分比

 public boolean isLowMemory()
 {
  int usedSize = 0;
  try
  {
   Runtime runtime = Runtime.getRuntime();
   final float usedMemInMB = (runtime.totalMemory() - runtime.freeMemory()) / 1048576L;
   final float maxHeapSizeInMB = runtime.maxMemory() / 1048576L;
   usedSize = (int) ((usedMemInMB / maxHeapSizeInMB) * 100);
  }
  catch (Exception e)
  {
   e.printStackTrace();
  }
  if (usedSize >= 80) { return true; }
  else { return false; }
 }