程序编译报错\USER\main.c(180): error: #268: declaration may not appear after executable statement in block NVIC_InitTypeDef NVIC_InitStructure;，修改NVIC_InitTypeDef NVIC_InitStructure; NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //设置抢占优先级为0，最高优先级 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //设置子优先级为0 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure);

你需要将 `NVIC_InitTypeDef NVIC_InitStructure;` 的定义放到前面的可执行语句之前。修改后的代码应该如下所示：

NVIC_InitTypeDef NVIC_InitStructure;
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

这样就可以避免编译报错了。

相关问题

main.c(239): error: #20: identifier "u16DacVal" is undefined DAC_SetChannel1Data(DAC_Align_12b_R,u16DacVal); //初始值为0 main.c(242): error: #268: declaration may not appear after executable statement in block u16 u16DacVal=0; main.c(244): error: #268: declaration may not appear after executable statement in block u16 adcx,adcy; //adcx存放整数，adcy存放小数 main.c(245): error: #268: declaration may not appear after executable statement in block float temp; //temp为DAC设置的数字量 main.c(247): error: #268: declaration may not appear after executable statement in block请给出具体措施修改这些代码

这段代码的问题是变量的声明出现在了可执行语句之后，导致编译器无法识别变量。要解决这个问题，需要将变量的声明放在可执行语句之前。

修改后的代码如下：

u16 u16DacVal=0;
u16 adcx,adcy;   //adcx存放整数，adcy存放小数
float temp;      //temp为DAC设置的数字量

DAC_SetChannel1Data(DAC_Align_12b_R,u16DacVal);  //初始值为0

这样就可以正确声明变量并使用了。

main.c(113): error: #268: declaration may not appear after executable statement in block const unsigned char *point; main.c(114): error: #268: declaration may not appear after executable statement in block u16 i=0;这两个错误具体如何修改

这两个错误是因为在代码块内部，先出现了可执行语句，再出现了变量声明语句。在 C 语言中，变量声明必须在可执行语句之前。

要修复这些错误，您需要将变量声明语句移动到代码块的开头。例如：

const unsigned char *point;
u16 i=0;

// 执行其他语句

或者，您也可以将变量声明语句放在代码块外部，以便在整个函数中都可以使用它们。例如：

const unsigned char *point;
u16 i=0;

int main(void) {
    // 执行其他语句
}