Uart2为什么没有中断产生

各位大侠，菜鸟我又遇到usart2的问题了，烦请哪位大侠指点迷津，谢谢！

我用了两个uart，uart1和uart2，uart1用来做smartcard接口，没问题，用的是查询
现在想用uart2中断来做rs232接口的条码扫描，条码扫描器没问题，用电脑测试过，电平转换max3232应该也没问题，从输出能看到信号，然后信号连到stm32的PA3也就是uart2的rx，信号过来了，但是就是没有进中断，困惑的不行。
相关设置如下：
void RS232_Interrupts_Config(void)
{
  NVIC_InitTypeDefHw NVIC_InitStructure;

  SCB->AIRCR = AIRCR_VECTKEY_MASK | NVIC_PriorityGroup_1;
  
  NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQChannel;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}
void UART2_GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  // Configure USART1_Tx as alternate function push-pull
  GPIO_InitStructure.GPIO_Pin = USARTy_TxPin;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  // Configure USART1_Rx as input floating
  GPIO_InitStructure.GPIO_Pin = USARTy_RxPin;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOA, &GPIO_InitStructure);  
}
void RS232_Usart_Configue(void ){
    /* Private variables ---------------------------------------------------------*/
    USART_InitTypeDef USART_InitStructure;
    USART_ClockInitTypeDef USART_ClockInitStructure;
    /* USARTy configuration ------------------------------------------------------*/
  /* USARTy configured as follow:
        - BaudRate = 9600baud  
        - Word Length = 8 Bits
        - One Stop Bit
        - No parity
        - Hardware flow control disabled (RTS and CTS signals)
        - Receive and transmit enabled
        - USART Clock Enabled
        - USART CPOL: Clock is active High
        - USART CPHA: Data is captured on the second edge
        - USART LastBit: The clock pulse of the last data bit is output to
                         the SCLK pin
  */
  USART_ClockInitStructure.USART_Clock = USART_Clock_Enable;
  USART_ClockInitStructure.USART_CPOL = USART_CPOL_High;
  USART_ClockInitStructure.USART_CPHA = USART_CPHA_2Edge;
  USART_ClockInitStructure.USART_LastBit = USART_LastBit_Enable;
  
  USART_ClockInit(USARTy, &USART_ClockInitStructure);

  USART_InitStructure.USART_BaudRate = 9600;
  USART_InitStructure.USART_WordLength = USART_WordLength_8b;
  USART_InitStructure.USART_StopBits = USART_StopBits_1;
  USART_InitStructure.USART_Parity = USART_Parity_No ;
  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
  USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
  
  USART_Init(USARTy, &USART_InitStructure);  
  
    /* Enable the USART1 */
  USART_Cmd(USART2, ENABLE);  

}

void USART2_IRQHandler(void)
{
  /* If the USART1 detects a parity error */
  if(USART2->SR & 0x00000002)
。。。。。。。。

}

渴求大虾指点！！