以下也是对库函数的改动
static HAL_StatusTypeDef UART_Receive_IT(UART_HandleTypeDef *huart)
{
  uint16_t* tmp;
  uint32_t tmp1 = 0;

  tmp1 = huart->State;
  if((tmp1 == HAL_UART_STATE_BUSY_RX) || (tmp1 == HAL_UART_STATE_BUSY_TX_RX))
  {
    if(huart->Init.WordLength == UART_WORDLENGTH_9B)
    {
      tmp = (uint16_t*) huart->pRxBuffPtr;
      if(huart->Init.Parity == UART_PARITY_NONE)
      {
        *tmp = (uint16_t)(huart->Instance->DR & (uint16_t)0x01FF);
        huart->pRxBuffPtr += 2;
      }
      else
      {
        *tmp = (uint16_t)(huart->Instance->DR & (uint16_t)0x00FF);
        huart->pRxBuffPtr += 1;
      }
    }
    else
    {
      if(huart->Init.Parity == UART_PARITY_NONE)
      {
        *huart->pRxBuffPtr++ = (uint8_t)(huart->Instance->DR & (uint8_t)0x00FF);
      }
      else
      {
        *huart->pRxBuffPtr++ = (uint8_t)(huart->Instance->DR & (uint8_t)0x007F);
      }
    }

    if(--huart->RxXferCount == 0)
    {
//      __HAL_UART_DISABLE_IT(huart, UART_IT_RXNE);

//      /* Check if a transmit process is ongoing or not */
//      if(huart->State == HAL_UART_STATE_BUSY_TX_RX)
//      {
//        huart->State = HAL_UART_STATE_BUSY_TX;
//      }
//      else
//      {
//        /* Disable the UART Parity Error Interrupt */
//        __HAL_UART_DISABLE_IT(huart, UART_IT_PE);

//        /* Disable the UART Error Interrupt: (Frame error, noise error, overrun error) */
//        __HAL_UART_DISABLE_IT(huart, UART_IT_ERR);

//        huart->State = HAL_UART_STATE_READY;
//      }
//      HAL_UART_RxCpltCallback(huart);
                /*以上注释掉的为原库代码，以下两行为用户添加的代码，
                 * 修改后，接受缓存为环形缓存。
            */
        huart->RxXferCount = huart->RxXferSize;//用户修改，非原库代码
        huart->pRxBuffPtr -= huart->RxXferSize;//用户修改，非原库代码
                       
      return HAL_OK;
    }
    return HAL_OK;
  }
  else
  {
    return HAL_BUSY;
  }
}