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+---
+date: "2025-07-12T00:26:59+08:00"
+draft: false
+categories: 
+- 往昔
+slug: ""
+title: C语言下的二进制文件IO踩坑
+---
+
+C语言下的二进制文件读写有个坑，就是一定要按存储的顺序读取。例：
+```c
+typedef struct player {
+	int id;
+	double XP;
+	double MP;
+}player;
+```
+
+这里有一个玩家的数据结构，我们创建变量并初始化。
+
+```c
+int b_i[32] = {1, 233, 2453, 5432, 21 ,43 ,297, 752, 643};
+player yingyu5658;
+yingyu5658.MP = 100;
+yingyu5658.XP = 100;
+yingyu5658.id = 114514;
+```
+
+对文件进行存储时，按照MP=>XP=>ID的顺序存储
+```c
+pd = fopen("./data", "wb");
+fwrite(&yingyu5658.MP, sizeof(double), 1, pd);
+fwrite(&yingyu5658.XP, sizeof(double), 1, pd);
+fwrite(&yingyu5658.id, sizeof(int), 1, pd);
+```
+
+读取的时候一定要按照这个顺序，否则读取出来的内容是无效的。
+
+```c
+int id;
+double XP, MP;
+pd = fopen("./data", "rb");
+fread(&MP, sizeof(double), 1, pd);
+fread(&XP, sizeof(double), 1, pd);
+fread(&id, sizeof(int), 1, pd);
+player new_player;
+new_player.id = id;
+new_player.XP = XP;
+new_player.MP = MP;
+printf("id: %d\n", new_player.id);
+printf("XP: %f\n", new_player.XP);
+printf("MP: %f\n", new_player.MP);
+```
+
+运行结果：	
+```
+写入了id: 114514
+写入了XP: 100.000000
+写入了MP: 100.000000
+
+id: 114514
+XP: 100.000000
+MP: 100.000000
+```
+
+使用完也要关闭流，否则资源泄漏
+```c
+fclose(pd);  // 必须显式关闭
+```