我要在keil中头文件声明和C文件定义头文件中的变量，可是我在头文件中声明后再到C文件中定义的时候
发布网友
发布时间：2022-04-24 12:43
共3个回答
热心网友
时间：2023-10-13 05:04
比如，你在X.c定义一个变量 unsigned char a;如果你想要在Y.C文件里使用这个变量，你可以在Y.C里引用，引用方法如下：extern unsigned char a;
你也可以在一个头文件里引用，引用方法是一样的：extern unsigned char a;
在头文件引用后，凡是包含了这个头文件的C文件，都可以使用那个变量a,而不必再另外引用了。
有一点要注意，引用的时候，不可以带初始化，例如，X.c文件里这样定义的变量：
unsigned char a = 100; 定义的时候可以初始化，在头文件或者其它C文件引用的时候，不能初始化，妈extern unsigned char a = 100;这是不可以的，直接引用就行了：extern unsigned char a;
热心网友
时间：2023-10-13 05:05
volatile signed int LatestCCI = 0; // most recent value of Instantaneous CC conversion
signed long CCoffset = 0x0000; // this is SUBTRACTED to EACH sample from the CC Accum.
signed int CCIoffset = 0; // this is in mA and is ONLY SUBTRACTED to the 1-second total, NOT TO EACH SAMPLE.
unsigned char FastRCCal = 0;
unsigned int SlowRCCal = 0;
unsigned char BGCCRCal = 0;
unsigned char ThermistorSelect = 0;
unsigned char CellToBalance = 0;
unsigned int cell_current[4]; //used for impedance measurement
signed long RunningAcc = 0;
#else
extern volatile signed int LatestCCI;
extern unsigned char FastRCCal;
extern unsigned int SlowRCCal;
extern unsigned char BGCCRCal;
extern unsigned char ThermistorSelect;
extern unsigned char CellToBalance;
extern unsigned int cell_current[4];
extern signed long RunningAcc;
#endif
热心网友
时间：2023-10-13 05:05
