网站注销备案,重庆网站建设只选承越,漳州网站开发找出博大科技,龙华网站建设主要工作概述 做项目#xff0c;掌握以下方法#xff0c;可提高开发效率#xff0c;把时间全部放在需求上。 1、快速获取结构体成员大小
#include stdio.h // 获取结构体成员大小
#define GET_MEMBER_SIZE(type, member) sizeof(((type*)0)-member)// 获取结构体成…概述 做项目掌握以下方法可提高开发效率把时间全部放在需求上。 1、快速获取结构体成员大小
#include stdio.h // 获取结构体成员大小
#define GET_MEMBER_SIZE(type, member) sizeof(((type*)0)-member)// 获取结构体成员偏移量
#define GET_MEMBER_OFFSET(type, member) ((size_t)((((type*)0)-member)))typedef struct _test_struct0
{char x;char y;char z;
}test_struct0;typedef struct _test_struct1
{char a;char c;short b;int d;test_struct0 e;
}test_struct1;int main(int arc, char* argv[])
{printf(GET_MEMBER_SIZE(test_struct1, a) %ld\n, GET_MEMBER_SIZE(test_struct1, a));printf(GET_MEMBER_SIZE(test_struct1, c) %ld\n, GET_MEMBER_SIZE(test_struct1, c));printf(GET_MEMBER_SIZE(test_struct1, b) %ld\n, GET_MEMBER_SIZE(test_struct1, b));printf(GET_MEMBER_SIZE(test_struct1, d) %ld\n, GET_MEMBER_SIZE(test_struct1, d));printf(GET_MEMBER_SIZE(test_struct1, e) %ld\n, GET_MEMBER_SIZE(test_struct1, e));printf(test_struct1 size %ld\n, sizeof(test_struct1));printf(GET_MEMBER_OFFSET(a): %ld\n, GET_MEMBER_OFFSET(test_struct1, a));printf(GET_MEMBER_OFFSET(c): %ld\n, GET_MEMBER_OFFSET(test_struct1, c));printf(GET_MEMBER_OFFSET(b): %ld\n, GET_MEMBER_OFFSET(test_struct1, b));printf(GET_MEMBER_OFFSET(d): %ld\n, GET_MEMBER_OFFSET(test_struct1, d));printf(GET_MEMBER_OFFSET(e): %ld\n, GET_MEMBER_OFFSET(test_struct1, e));return 0;
}运行结果 2、文件操作
文件操作平时用得很多为了方便使用可以自己根据实际需要再封装一层
#include stdio.h static int file_opt_write(const char* filename, void* ptr, int size)
{FILE* fp;size_t num;fp fopen(filename, wb);if (NULL fp){printf(open %s file error!\n, filename);return -1;}num fwrite(ptr, 1, size, fp);if (num ! size){fclose(fp);printf(write %s file error!\n, filename);return -1;}fclose(fp);return num;
}static int file_opt_read(const char* filename, void* ptr, int size)
{FILE* fp;size_t num;fp fopen(filename, rb);if (NULL fp){printf(open %s file error!\n, filename);return -1;}num fread(ptr, 1, size, fp);if (num ! size){fclose(fp);printf(write %s file error!\n, filename);return -1;}fclose(fp);return num;
}typedef struct _test_data_info
{char a;char c;short b;int d;
}test_data_info;int main(int arc, char* argv[])
{
#define FILE_NAME ./test_filetest_data_info write_data { 0 };write_data.a 1;write_data.b 2;write_data.c 3;write_data.d 4;printf(write_data.a %d\n, write_data.a);printf(write_data.b %d\n, write_data.b);printf(write_data.c %d\n, write_data.c);printf(write_data.d %d\n, write_data.d);file_opt_write(FILE_NAME, (test_data_info*)write_data, sizeof(test_data_info));test_data_info read_data { 0 };file_opt_read(FILE_NAME, (test_data_info*)read_data, sizeof(test_data_info));printf(read_data.a %d\n, read_data.a);printf(read_data.b %d\n, read_data.b);printf(read_data.c %d\n, read_data.c);printf(read_data.d %d\n, read_data.d);return 0;
}
运行结果 3、进度条
有时候加上进度条可以比较方便知道当前的下载进度、写入文件的进度等。
#include stdio.h
#include string.h
#include windows.htypedef struct _progress_t
{int cur_size;int sum_size;
}progress_t;void progress_bar(progress_t* progress_data)
{int percentage 0;int cnt 0;char proBuf[102];memset(proBuf, \0, sizeof(proBuf));percentage (int)(progress_data-cur_size * 100 / progress_data-sum_size);printf(percentage %d %%\n, percentage);if (percentage 100){while (cnt percentage){printf([%-100s] [%d%%]\r, proBuf, cnt);fflush(stdout);proBuf[cnt] #;Sleep(1);cnt;}}printf(\n);
}int main(int arc, char* argv[])
{progress_t progress_test { 0 };progress_test.cur_size 82;progress_test.sum_size 100;progress_bar(progress_test);return 0;
}
运行结果 4、日志输出
日志输出常常需要带一些格式。最简单的方式如
// 定义日志等级
typedef enum {LOG_DEBUG,LOG_INFO,LOG_WARNING,LOG_ERROR,
} log_level_t;// 封装的日志函数
void log_message(log_level_t level, const char* message, const char* file, int line) {switch (level) {case LOG_DEBUG:printf(DEBUG: %s (%s:%d)\n, message, file, line);break;case LOG_INFO:printf(INFO: %s (%s:%d)\n, message, file, line);break;case LOG_WARNING:printf(WARNING: %s (%s:%d)\n, message, file, line);break;case LOG_ERROR:printf(ERROR: %s (%s:%d)\n, message, file, line);break;default:break;}
}// 在代码中使用封装的日志函数
int main() {log_message(LOG_INFO, This is an info message, __FILE__, __LINE__);log_message(LOG_DEBUG, This is a debug message, __FILE__, __LINE__);log_message(LOG_WARNING, This is a warning message, __FILE__, __LINE__);log_message(LOG_ERROR, This is an error message, __FILE__, __LINE__);return 0;
}
运行结果 5、总结 介绍完毕希望能帮助到你蟹蟹参阅
