串口实验遇到的问题？关于结构体指针的问题。

熬夜从不掉头发

在学习正点原子串口实验时，定义GPIO_InitTypeDef *GPIO_InitStructure;        USART_InitTypeDef *USART_InitStructure;        NVIC_InitTypeDef *NVIC_InitStructure则串口输入无返回值，        GPIO_InitTypeDef  GPIO_InitStructure;        USART_InitTypeDef   USART_InitStructure;        NVIC_InitTypeDef  NVIC_InitStructure;则串口助手有值，代码基本和原子哥视频中的一致，请问这是怎么回事啊？


代码一（串口助手无返回值）：
#include "stm32f10x.h"
void MY_USART_Init(void)
{
        GPIO_InitTypeDef *GPIO_InitStructure;       
        USART_InitTypeDef *USART_InitStructure;       
        NVIC_InitTypeDef *NVIC_InitStructure;
//串口时钟使能\GPIO时钟使能
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA,ENABLE);
//GPIO初始化       
        GPIO_InitStructure->GPIO_Pin=GPIO_Pin_9;
        GPIO_InitStructure->GPIO_Speed=GPIO_Speed_10MHz;
        GPIO_InitStructure->GPIO_Mode=GPIO_Mode_AF_PP;
        GPIO_Init(GPIOA, GPIO_InitStructure);                
        GPIO_InitStructure->GPIO_Pin=GPIO_Pin_10;
        GPIO_InitStructure->GPIO_Mode=GPIO_Mode_IN_FLOATING;
        GPIO_InitStructure->GPIO_Speed=GPIO_Speed_10MHz;
        GPIO_Init(GPIOA, GPIO_InitStructure);
//串口参数初始化
        USART_InitStructure->USART_BaudRate =115200;
        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; //使能
        USART_Init(USART1,USART_InitStructure);
//使能串口
        USART_Cmd(USART1,ENABLE);       
//开启中断接收
        USART_ITConfig(USART1, USART_IT_RXNE,ENABLE);               
        //开启中断
        NVIC_InitStructure->NVIC_IRQChannel=USART1_IRQn;//此处是什么意思？？？
        NVIC_InitStructure->NVIC_IRQChannelCmd=ENABLE;
        NVIC_InitStructure->NVIC_IRQChannelPreemptionPriority=1;
        NVIC_InitStructure->NVIC_IRQChannelSubPriority=1;
        NVIC_Init(NVIC_InitStructure);
}

void USART1_IRQHandler(void)
{
        u8 res;
        if(USART_GetITStatus(USART1,USART_IT_RXNE))
        {
                res=USART_ReceiveData(USART1);
                USART_SendData(USART1,res);
        }

}

int main(void)
{
        NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
        MY_USART_Init();
       
        while(1);       

}




代码二（串口助手有返回值）：
#include "stm32f10x.h"
void My_USART1_Init(void)
{
       
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;       
        NVIC_InitTypeDef NVIC_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_USART1,ENABLE);       
//RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);       
       
GPIO_InitStructure.GPIO_Mode =GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_9 ;
GPIO_InitStructure.GPIO_Speed =GPIO_Speed_10MHz;       

GPIO_Init(GPIOA,&GPIO_InitStructure);
       
GPIO_InitStructure.GPIO_Mode =GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_10 ;
GPIO_InitStructure.GPIO_Speed =GPIO_Speed_10MHz;       
//RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);       
//RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);
GPIO_Init(GPIOA,&GPIO_InitStructure);


USART_InitStructure.USART_BaudRate =115200;       
USART_InitStructure.USART_HardwareFlowControl=USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode=USART_Mode_Rx|USART_Mode_Tx;
USART_InitStructure.USART_Parity=USART_Parity_No;
USART_InitStructure.USART_StopBits=USART_StopBits_1;
USART_InitStructure.USART_WordLength=USART_WordLength_8b;
USART_Init(USART1,&USART_InitStructure);


USART_Cmd(USART1,ENABLE);

USART_ITConfig(USART1,USART_IT_RXNE,ENABLE);

NVIC_InitStructure.NVIC_IRQChannel =USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority=1;
NVIC_Init(&NVIC_InitStructure);

}

void USART1_IRQHandler(void)
{
        u8 res;
if(USART_GetITStatus(USART1,USART_IT_RXNE))
{
res = USART_ReceiveData(USART1);
        USART_SendData(USART1,res);
}
}


int main(void)
{       
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
My_USART1_Init();
         
         while(1);
}