public static SDCardInfo getSDCardInfo() {
  String sDcString = android.os.Environment.getExternalStorageState();
  if (sDcString.equals(android.os.Environment.MEDIA_MOUNTED)) {
   File pathFile = android.os.Environment.getExternalStorageDirectory();
   try {
    android.os.StatFs statfs = new android.os.StatFs(pathFile.getPath());
    // 获取SDCard上BLOCK总数
    long nTotalBlocks = statfs.getBlockCount();
    // 获取SDCard上每个block的SIZE
    long nBlocSize = statfs.getBlockSize();
    // 获取可供程序使用的Block的数量
    long nAvailaBlock = statfs.getAvailableBlocks();
    // 获取剩下的所有Block的数量(包括预留的一般程序无法使用的块)
    long nFreeBlock = statfs.getFreeBlocks();
    SDCardInfo info = new SDCardInfo();
    // 计算SDCard 总容量大小MB
    info.total = nTotalBlocks * nBlocSize;
    // 计算 SDCard 剩余大小MB
    info.free = nAvailaBlock * nBlocSize;
    return info;
   } catch (IllegalArgumentException e) {
    Log.e(LOG_TAG, e.toString());
   }
  }
  return null;
}
SDCardInfo sdCardInfo = Util.getSDCardInfo();
// sd卡总容量
sdCardInfo.total
// sd卡剩余容量
sdCardInfo.free