如题，在所提供例程 “外部中断实验”的基础上，我另外开了一个PD1的中断，却发现中断服务函数不响应。请教这是为什么？谢谢。
 GPIO_EXTILineConfig(GPIO_PortSourceGPIOD,GPIO_PinSource1);           EXTI_InitStructure.EXTI_Line = EXTI_Line1;
          EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; 
          EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
          EXTI_InitStructure.EXTI_LineCmd = ENABLE;
          EXTI_Init(&EXTI_InitStructure);  //?ù??EXTI_InitStruct?????¨???????????????èEXTI?????÷
          
          NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;   //????°??ü?ù?????????????¨??
          NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02; //??????????2??
          NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;     //×???????1
          NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;        //?????????????¨??
          NVIC_Init(&NVIC_InitStructure);  RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
服务函数为： void EXTI1_IRQHandler(void)                //
{      if(EXTI_GetITStatus(EXTI_Line1)!=RESET)//
     {

      TEST_LED=~TEST_LED;             //
      
      EXTI_ClearITPendingBit(EXTI_Line1);//
     }
}
TEST_LED 是我自己设置的一个IO 方便测试，响应后反转。谢谢大家