出现两个问题：1、WK_UP按键为什么是下拉输入(WK_UP按键外部接高电平的原因？)
2、 GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource2|GPIO_PinSource3|GPIO_PinSource4);//不能合起来写

EXTI_InitStruct.EXTI_Line=EXTI_Line2|EXTI_Line3|EXTI_Line4;//但是这个可以合起来写。

#include "stm32f10x.h"
#include "BEEP.h"
#include "LED.h"
#include "delay.h"
#include "usart.h"	 
void myExitHandler();

int main(void)
{	
	//设置中断分组2
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	LED_Init();
	BEEP_Init();
	uart_init(115200);
	myExitHandler();
	
	while(1);
}

void myExitHandler()
{
	GPIO_InitTypeDef GPIO_InitStruct;
	EXTI_InitTypeDef EXTI_InitStruct;
	NVIC_InitTypeDef NVIC_InitStruct;
	
	//1、使能时钟 GPIO口时钟，外部中断时钟  GPIOE2,3,4 //KEY0-KEY2    WK_UP-->GPIOA.0
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOE|RCC_APB2Periph_AFIO,ENABLE);
	
	//2、初始化GPIO口，作为输入口
	//WK_UP-->GPIOA.0
	GPIO_InitStruct.GPIO_Mode=GPIO_Mode_IPD;//下拉输入
//	GPIO_InitStruct.GPIO_Mode=GPIO_Mode_IPU;//上拉输入
	GPIO_InitStruct.GPIO_Pin=GPIO_Pin_0;
	GPIO_InitStruct.GPIO_Speed=GPIO_Speed_10MHz;
	GPIO_Init(GPIOA,&GPIO_InitStruct);
	
	//KEY0-KEY2 ->GPIOE2,3,4 
	GPIO_InitStruct.GPIO_Mode=GPIO_Mode_IPU;//上拉输入
//	GPIO_InitStruct.GPIO_Mode=GPIO_Mode_IPD;//下拉输入
	GPIO_InitStruct.GPIO_Pin=GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4;
	GPIO_InitStruct.GPIO_Speed=GPIO_Speed_10MHz;
	GPIO_Init(GPIOE,&GPIO_InitStruct);
	
	//3、IO口映射到中断线上
	//WK_UP-->GPIOA.0
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource0);
	//4、初始化线上中断， 设置触发条件
	EXTI_InitStruct.EXTI_Line=EXTI_Line0;
	EXTI_InitStruct.EXTI_LineCmd=ENABLE;
	EXTI_InitStruct.EXTI_Mode=EXTI_Mode_Interrupt;
	EXTI_InitStruct.EXTI_Trigger=EXTI_Trigger_Rising;//上升沿触发
	EXTI_Init(&EXTI_InitStruct);
	
	//KEY0-KEY2 ->GPIOE2,3,4 
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource2);
	
	//4、初始化线上中断， 设置触发条件
	EXTI_InitStruct.EXTI_Line=EXTI_Line2;
	EXTI_InitStruct.EXTI_LineCmd=ENABLE;
	EXTI_InitStruct.EXTI_Mode=EXTI_Mode_Interrupt;
	EXTI_InitStruct.EXTI_Trigger=EXTI_Trigger_Falling;//下升沿触发
	EXTI_Init(&EXTI_InitStruct);
	
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource3);
	EXTI_InitStruct.EXTI_Line=EXTI_Line3;
	EXTI_Init(&EXTI_InitStruct);
	
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource4);
	EXTI_InitStruct.EXTI_Line=EXTI_Line4;
	EXTI_Init(&EXTI_InitStruct);
	
	//5、配置中断参数
	//WK_UP-->GPIOA.0
	NVIC_InitStruct.NVIC_IRQChannel=EXTI0_IRQn;
	NVIC_InitStruct.NVIC_IRQChannelCmd=ENABLE;
	NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority=3;
	NVIC_InitStruct.NVIC_IRQChannelSubPriority=3;
	NVIC_Init(&NVIC_InitStruct);
	
	//KEY0-->GPIOE2
	NVIC_InitStruct.NVIC_IRQChannel=EXTI2_IRQn;
	NVIC_InitStruct.NVIC_IRQChannelCmd=ENABLE;
	NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority=0;
	NVIC_InitStruct.NVIC_IRQChannelSubPriority=1;
	NVIC_Init(&NVIC_InitStruct);
	
	//KEY1-->GPIOE3
	NVIC_InitStruct.NVIC_IRQChannel=EXTI3_IRQn;
	NVIC_InitStruct.NVIC_IRQChannelCmd=ENABLE;
	NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority=1;
	NVIC_InitStruct.NVIC_IRQChannelSubPriority=1;
	NVIC_Init(&NVIC_InitStruct);
	
	//KEY2-->GPIOE4
	NVIC_InitStruct.NVIC_IRQChannel=EXTI4_IRQn;
	NVIC_InitStruct.NVIC_IRQChannelCmd=ENABLE;
	NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority=2;
	NVIC_InitStruct.NVIC_IRQChannelSubPriority=1;
	NVIC_Init(&NVIC_InitStruct);

}

//WK_UP GPIOA.0控制蜂鸣器，按一次叫，再按一次停；
void EXTI0_IRQHandler(void)
{
	if(EXTI_GetITStatus(EXTI_Line0))
	{
		BEEP=~BEEP;
		EXTI_ClearITPendingBit(EXTI_Line0);
	}
		
}

//KEY0 GPIOE2 则同时控制 DS0 和 DS1，按一次，他们的状态就翻转一次
void EXTI2_IRQHandler(void)
{
	if(EXTI_GetITStatus(EXTI_Line2))
	{
		LED1=~LED1;
		LED0=~LED0;
		EXTI_ClearITPendingBit(EXTI_Line2);
	}
}

//KEY1 GPIOE3 控制 DS1，按一次亮，再按一次灭；
void EXTI3_IRQHandler(void)
{
	if(EXTI_GetITStatus(EXTI_Line3))
	{
		LED1=~LED1;
		EXTI_ClearITPendingBit(EXTI_Line3);
	}
}

//KEY2 GPIOE4 控制 DS0，按一次亮，再按一次灭； 
void EXTI4_IRQHandler(void)
{
	if(EXTI_GetITStatus(EXTI_Line4))
	{
		LED0=~LED0;
		EXTI_ClearITPendingBit(EXTI_Line4);
	}
}