这是出问题的函数块儿

void CompareData(wchar_t username[20], wchar_t password[20]) {
	char un[256], pw[256];
	//printf("before username %20S\n", username);
	//printf("before password %20S\n", password);
	WideCharToMultiByte(CP_ACP, 0, username, wcslen(username) + 1, un, 256, NULL, NULL);
	WideCharToMultiByte(CP_ACP, 0, password, wcslen(password) + 1, pw, 256, NULL, NULL);
	//printf("char username %20s\n", un);
	//printf("char password %20s\n", pw);
	userdata data[20] = { 0 };
	FILE* file;

	file = fopen("D:\\myproj\\Signin\\Debug\\userdata\\data.txt", "a+");//创建文件对象
	if (NULL == file) {
		printf("Open file failed or no this file!\n");
		return;
	}//判断文件是否正常打开
	int i = 0;
	while (!feof(file)) {
		fscanf(file, "%s%s", data[i].userName, data[i].passWord);
		i++;
	}//将文件中的用户数据赋给预备好的空结构体
	int cycle;
	do {
		for (cycle = 0; cycle < i; cycle++) {



			if (strcmp(un, data[cycle].userName) == 0&&strcmp(pw, data[cycle].passWord) == 0) {//就是这里有问题




				LOGFONT f;
				cleardevice(); // 清除屏幕
				putimage(0, 0, &img_background);
				DrawInputBox(500, 300, 1000, 340, input_pw);
				settextcolor(RED); // 设置字体颜色
				outtextxy(300, 550, L"登录成功。");
				FlushBatchDraw();
				break;
			}
		}
		if (cycle == i) {
			userdata* p = (userdata*)malloc(sizeof(userdata));
			strcpy(p->userName, un);//把username的值赋给结构体内的变量
			strcpy(p->passWord, pw);
			fprintf(file, "%s%s", p->userName, p->passWord);
			cleardevice(); // 清除屏幕
			putimage(0, 0, &img_background);
			DrawInputBox(500, 300, 1000, 340, input_pw);
			settextcolor(RED); // 设置字体颜色
			outtextxy(300, 550, L"您输入的账号或密码错误，已经帮您注册新用户。");
			FlushBatchDraw();
			free(p);
			break;
		}
	} while (1);
	fclose(file);
}

不能发图片我就挂个链接

麻烦大佬帮我看一下到底是怎么回事

拜托了QAQ

https://blog.csdn.net/Solmane/article/details/106629007