硬盘0磁道读写.txt

硬盘0磁道读写

硬盘0磁道i/o读写问题
DWORD CDiskInfo::WriteDiskSector(DWORD LogicSector, 						unsigned char *str)
{
	HANDLE hDevice = CreateFile("\\\\.\\PhysicalDrive0", GENERIC_READ,
		FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL);
	if(hDevice == INVALID_HANDLE_VALUE)
	{
		AfxMessageBox("Can't open disk");
		CloseHandle(hDevice);
		return FALSE;
	}
	long hi = LogicSector >> 23;

	SetFilePointer(hDevice, 
		(long)((LogicSector * Disk_Geometry.BytesPerSector) % 
		0x100000000), &hi, FILE_BEGIN);

	DWORD write;

	WriteFile(hDevice, str, 512, 
		&write, NULL);
	
	CloseHandle(hDevice);
	return write;

}
///////////////////////////
DWORD CDiskInfo::WriteDiskSector(DWORD LogicSector, 
								 unsigned char *str)
{
	HANDLE hDevice = CreateFile("\\\\.\\PhysicalDrive0", GENERIC_WRITE,
		FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
	if(hDevice == INVALID_HANDLE_VALUE)
	{
		AfxMessageBox("Can't open disk");
		CloseHandle(hDevice);
		return FALSE;
	}
	long hi = LogicSector >> 23;

	SetFilePointer(hDevice, 
		(long)((LogicSector * Disk_Geometry.BytesPerSector) % 
		0x100000000), &hi, FILE_BEGIN);

	DWORD write;

	WriteFile(hDevice, str, Disk_Geometry.BytesPerSector, 
		&write, NULL);
	
	CloseHandle(hDevice);
	return write;

}
上面有两个参数错了。我在2000下运行了没问题
yaolan1999(可可猫) ：
能否告知變量LogicSector如何獲得，同時long hi = LogicSector >> 23;的意義爲何？
Disk_Geometry是否是由函數GetDiskGeometry（hDevice，Disk_Geometry）得到？
这是一个函数，LogicSector == 0表示写第一个扇区。Disk_Geometry.BytesPerSector为一个扇区的字节数，一般为512。long hi = LogicSector >> 23表示取扇区的高字位，由于512 == 2的9次方，因此还要移32-9=23位。
DWORD CDiskInfo::ReadDiskSector(DWORD LogicSector, 
								unsigned char *str)
{
	HANDLE hDevice = CreateFile("\\\\.\\PhysicalDrive0", GENERIC_READ,
		FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL);
	if(hDevice == INVALID_HANDLE_VALUE)
	{
		AfxMessageBox("Can't open disk");
		CloseHandle(hDevice);
		return FALSE;
	}
	long hi = LogicSector >> 23;

	SetFilePointer(hDevice, 
		(long)((LogicSector * Disk_Geometry.BytesPerSector) % 
		0x100000000), &hi, FILE_BEGIN);

	DWORD read;

	ReadFile(hDevice, str, Disk_Geometry.BytesPerSector, 
		&read, NULL);
	
	CloseHandle(hDevice);
	return read;

}
不好意思再问两个，若作答分全给你：
1：按你的代码写入到的是0磁道吗？
2：往0柱面0磁道1扇区写东西是很危险的，但还是想知道如何定这个位呢，就是保证写
就是保证写入位置的准确性？
你先写另一个扇区试试如第二扇区。
unsigned char *str;
for(int i = 0; i < 512; i++)
str[i] = 1;
WriteDiskSector(1, str);
应该没问题。你也可以先读

unsigned char *str;
str = malloc(512);
ReadDiskSector(0, str);
注意str = malloc(512);不能少不然会读失败。
非常感谢你,yaolan1999(可可猫) !
不过有点笔误：修改成unsigned char * str = (unsigned char *)malloc(512);
则完美无缺！