是这样的，我写了一个CAN接收的函数，然后在接收的中断函数中将CAN接收到的数据打印出来。一直没有打印出来，我就单步调试。在单步调试的情况下，我可以看到寄存器中的值是正确的。
hcan->pRxMsg->RTR = (uint8_t)0x02U & hcan->Instance->sFIFOMailBox[FIFONumber].RIR;
  /* Get the DLC */
  hcan->pRxMsg->DLC = (uint8_t)0x0FU & hcan->Instance->sFIFOMailBox[FIFONumber].RDTR;
  /* Get the FIFONumber */
  hcan->pRxMsg->FIFONumber = FIFONumber;
  /* Get the FMI */
  hcan->pRxMsg->FMI = (uint8_t)0xFFU & (hcan->Instance->sFIFOMailBox[FIFONumber].RDTR >> 8U);
  /* Get the data field */
  hcan->pRxMsg->Data[0U] = (uint8_t)0xFFU & hcan->Instance->sFIFOMailBox[FIFONumber].RDLR;
  hcan->pRxMsg->Data[1U] = (uint8_t)0xFFU & (hcan->Instance->sFIFOMailBox[FIFONumber].RDLR >> 8U);
  hcan->pRxMsg->Data[2U] = (uint8_t)0xFFU & (hcan->Instance->sFIFOMailBox[FIFONumber].RDLR >> 16U);
  hcan->pRxMsg->Data[3U] = (uint8_t)0xFFU & (hcan->Instance->sFIFOMailBox[FIFONumber].RDLR >> 24U);
  hcan->pRxMsg->Data[4U] = (uint8_t)0xFFU & hcan->Instance->sFIFOMailBox[FIFONumber].RDHR;
  hcan->pRxMsg->Data[5U] = (uint8_t)0xFFU & (hcan->Instance->sFIFOMailBox[FIFONumber].RDHR >> 8U);
  hcan->pRxMsg->Data[6U] = (uint8_t)0xFFU & (hcan->Instance->sFIFOMailBox[FIFONumber].RDHR >> 16U);
  hcan->pRxMsg->Data[7U] = (uint8_t)0xFFU & (hcan->Instance->sFIFOMailBox[FIFONumber].RDHR >> 24U);

这是库函数的接收中断函数，但不调试明显可以看到寄存器中的值（也就是=后面的值是对的，但就不能正常赋值给前面的数）是正确。所以请各位大神给指导一下，是怎么回事呢？