100分送(二进制文件操作问题）

[tangshiping]

要实现的目标：
代码
char head[]={0X52,0X49,0X46,0X46,0X4C,0XD5,0X0C,0X00,0X57,0X41,0X56,0X45,0X66,0X6D,0X74,0X20,0X10,0X00,0X00,0X00,0X01,0X00,0X02,0X00,0X22,0X56,0X00,0X00,0X44,0XAC,0X00,0X00,0X02,0X00,0X08,0X00,0X64,0X61,0X74,0X61,0X28,0XD5,0X0C,0X00};
filenew.Write(head, sizeof(head));
把head写入到了文件，做文件的头部（后面还要另外跟一块二进制的数据），其中最后的0X28,0XD5,0X0C,0X00（十进制的841000）是后面接着的数据块的大小，
由于后面的数据块大小不是确定的，所以最后的几个字节型的变量也是不定的。
现用下面方法：

CFile file;
file.Open("e:\\new.wav",CFile::typeBinary|CFile::modeWrite|CFile::modeCreate);
CString binsize1;
CString binsize2;
binsize1 = filesize("e:\\new.wav");//后边的数据部分
sprintf(binsize2,"%X",binsize1);
char head[]={0X52,0X49,0X46,0X46,0X4C,0XD5,0X0C,0X00,0X57,0X41,0X56,0X45,0X66,0X6D,0X74,0X20,0X10,0X00,0X00,0X00,0X01,0X00,0X02,0X00,0X22,0X56,0X00,0X00,0X44,0XAC,0X00,0X00,0X02,0X00,0X08,0X00,0X64,0X61,0X74,0X61}；
filenew.Write(head, sizeof(head));
filenew.Write(“？？？？？？”);//这里面怎么写？
由于菜鸟程度比较高，所以这部分代码不知道怎么写了。麻烦写详细点，全分相赠！