Android计算当前手机内存使用率

/** * 计算已使用内存的百分比，并返回。 */public static String getUsedPercentValue(Context context) {   String dir = "/proc/meminfo";   try {      FileReader fr = new FileReader(dir);      BufferedReader br = new BufferedReader(fr, 2048);      String memoryLine = br.readLine();      String subMemoryLine = memoryLine.substring(memoryLine.indexOf("MemTotal:"));      br.close();      long totalMemorySize = Integer.parseInt(subMemoryLine.replaceAll("\\D+", ""));      long availableSize = getAvailableMemory(context) / 1024;      int percent = (int) ((totalMemorySize - availableSize) / (float) totalMemorySize * 100);      return percent + "%";   } catch (IOException e) {      e.printStackTrace();   }   return "";}/** * 获取当前可用内存，返回数据以字节为单位。 */private static long getAvailableMemory(Context context) {   ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();   getActivityManager(context).getMemoryInfo(mi);   return mi.availMem;}