用fopen打开的文件，如何向其头部加入内容？？

[cbz]

大家好，我下面的程序有什么不对的吗？
AnsiString buffer = "例子";
int length = strlen(buffer.c_str());
FILE *fp = fopen("c:\\windows\\desktop\\test.txt","r+b");
fseek(fp,0,SEEK_END);
int FileSize = ftell(fp);
fseek(fp,0,SEEK_SET);
char *buffer = new char[FileSize + length];
fread(buffer,1,FileSize,fp);
memmove(buffer + length,buffer,FileSize);
memset(buffer,0,length);
strncpy(buffer,buffer.c_str(),length);
fwrite(buffer,1,length,fp);
delete[] buffer;
fclose(fp);

[halibut]

先保存原有的内容呀,写入新内容,再把原有的内容保存回去!

[cbz]

我上面的程序就是这样的啊，不过，结果不正确啊，帮看看程序哪里错了

[halibut]

....
char data[]="例子";

int length = strlen(data);
FILE *fp = fopen("c:\\windows\\desktop\\test.txt","r+b");
fseek(fp,0,SEEK_END);
int FileSize = ftell(fp);
fseek(fp,0,SEEK_SET);
char *buffer = new char[FileSize + length];
fread(buffer+length,FileSize,1,fp);
memcpy(buffer,data,length);
fwrite(buffer,length,1,fp);
delete[] buffer
....

[cbz]

不行，楼上的，不过还是谢谢

[hnwlk]

FILE *fp = fopen("c:\\windows\\desktop\\test.txt","r+b");
改为：
FILE *fp = fopen("c:\\windows\\desktop\\test.txt","rb+");

[kingfish]

fseek(fp,0,SEEK_SET); //加一句
fwrite(buffer,1,length+FileSize,fp); //改这句