用C语言如何将读到的十六进制信息，再以十六进制形式写入到一个txt文件中呢？

Question

int main()
{
FILE * fpPhoto, *Head_w;//定义指向文件的指针
unsigned char Exif;

 fopen_s(&fpPhoto,"E:\\吴老师\\wu teacher\\DJI_0001.JPG", "rb");//以只读方式打开一个二进制文件

if (!fpPhoto)
{
    printf("打开文件失败！\n");
    system("pause");
    return -1;
}
else
{
    printf("打开成功！\n");
    fseek(fpPhoto, 3L, SEEK_SET);
    fread(&Exif, sizeof(unsigned char), 1, fpPhoto);

    printf("%x\n%d",Exif,Exif );
}
Exif = 97;
fopen_s(&Head_w, "C:\\Users\\Administrator\\Desktop\\01.txt", "w");//以只写方式打开一个文本文件，指定文件不存在，建立新文件
fwrite(&Exif, sizeof(unsigned char), 1, Head_w);

fclose(fpPhoto);
fclose(Head_w);
system("pause");
return 0;

}

Answer 1

void readPNGAndPrintHex(const string &originalPath,const string &targetPath)
{
FILE *pngFile,*targetFile;
fopen_s(&pngFile, originalPath.c_str(), "r");
if (pngFile == NULL)
{
printf("以r模式打开%s失败!!!", originalPath);
return;
}
fopen_s(&targetFile, targetPath.c_str(), "w+");
if (targetFile == NULL)
{
printf("以w+模式打开%s失败!!!", targetPath);
}

char buffer;
size_t size;
while (size = fread(&buffer,sizeof(char),1,pngFile))
{
    char s2[256];
    sprintf_s(s2, 256,"%x", buffer);
    fwrite(s2, sizeof(char), 1, targetFile);
}

fclose(targetFile);
fclose(pngFile);

}