DWORD GetLogicalDrives(VOID);
MSDN Description: If the function succeeds, the return value is a bitmask representing the
currently available disk drives. Bit position 0 (the least-significant bit) is
drive A, bit position 1 is drive B, bit position 2 is drive C, and so on.
该函数的返回值是一个无符号的32位整数,每一位代表一个驱动器,Bit 0代表驱动器A, Bit 1代表驱动器B, Bit 2代表驱动器C,依次类推。如果该位为1,表示该驱动器存在,否则不存在。
类似函数:
DWORD GetLogicalDriveStrings(
DWORD nBufferLength, // size of buffer
LPTSTR lpBuffer // pointer to buffer for drive strings
);
Parameters
- nBufferLength
- Specifies the maximum size, in characters, of the buffer pointed to by
lpBuffer. This size does not include the terminating null character.
- lpBuffer
- Pointer to a buffer that receives a series of null-terminated strings, one
for each valid drive in the system, that end with a second null character. The
following example shows the buffer contents with representing the
terminating null character.
c:\d:\
Return Values
If the function succeeds, the return value is the length, in characters, of
the strings copied to the buffer, not including the terminating null character.
Note that an ANSI-ASCII null character uses one byte, but a Unicode null
character uses two bytes.
If the buffer is not large enough, the return value is greater than
nBufferLength. It is the size of the buffer required to hold the drive
strings.
If the function fails, the return value is zero.
UINT GetDriveType(
LPCTSTR lpRootPathName // pointer to root path
);
The
GetDriveType function determines whether a disk drive is a removable,
fixed, CD-ROM, RAM disk, or network drive.
Parameters
- lpRootPathName
- Pointer to a null-terminated string that specifies the root directory of the
disk to return information about. If lpRootPathName is NULL, the function
uses the root of the current directory.
Return Values
The return value specifies the type of drive. It can be one of the following
values:
Value |
Meaning |
DRIVE_UNKNOWN |
The drive type cannot be determined. |
DRIVE_NO_ROOT_DIR |
The root directory does not exist. |
DRIVE_REMOVABLE |
The disk can be removed from the drive. |
DRIVE_FIXED |
The disk cannot be removed from the drive. |
DRIVE_REMOTE |
The drive is a remote (network) drive. |
DRIVE_CDROM |
The drive is a CD-ROM drive. |
DRIVE_RAMDISK |
The drive is a RAM disk. |
依据上面的函数我们来看一个实际的例子:
/* GetDriveInfo1.c */
#include
#include
int main()
{
DWORD dwRtn = GetLogicalDrives();
char c = 'A';
char drive[4];
char output[64];
while ( dwRtn )
{
if ( dwRtn & 1 )
{
sprintf(drive, "%c:\\", c);
switch ( GetDriveType(drive) )
{
case DRIVE_FIXED:
sprintf(output, "%c: -- Drive Fixed\n", c);
break;
case DRIVE_REMOVABLE:
sprintf(output, "%c: -- Drive Removable\n", c);
break;
case DRIVE_REMOTE:
sprintf(output, "%c: -- Drive Remote\n", c);
break;
case DRIVE_CDROM:
sprintf(output, "%c: -- CD-Rom\n", c);
break;
case DRIVE_RAMDISK:
sprintf(output, "%c: -- Ram Disk\n", c);
break;
default:
sprintf(output, "%c: -- Unknown drive\n", c);
break;
}
printf("%s", output);
}
c++;
dwRtn >>= 1;
}
return 0;
}
- 该例子根据GetLogicalDrives获取驱动器数目和名称,再根据GetDriveType获取驱动器的类型。
驱动器是从'A'开始的,如果存在,则打印出来。将GetLogicalDrives的返回值循环移位,然后再和1相与就能得出驱动器的数目和盘符。而GetDriveType的返回值则代表了驱动器的类型。
用GetLogicalDriveStrings来获得驱动器:
/* GetDriveInfo2.c */
#include
#include
int main()
{
char Buf[256];
char TmpDrive[4];
int i, j = 0;
char strType[32];
UINT uType;
DWORD dwRtn ;
memset(Buf, 0, 256);
dwRtn = GetLogicalDriveStrings(256, Buf);
for ( i=0; i < (int)dwRtn; i++ )
{
if ( Buf[i] == 0 )
{
if ( Buf[i+1] != 0 || (Buf[i+1] == 0 && Buf[i+2] == 0 ))
{
TmpDrive[j] = Buf[i];
j = 0;
uType = GetDriveType(TmpDrive);
switch(uType)
{
case DRIVE_REMOVABLE:
sprintf(strType, "Removable");
break;
case DRIVE_FIXED:
sprintf(strType, "Fixed Drive");
break;
case DRIVE_REMOTE:
sprintf(strType, "Remote Drive");
break;
case DRIVE_CDROM:
sprintf(strType, "CD-Rom");
break;
case DRIVE_RAMDISK:
sprintf(strType, "Ram disk");
break;
default:
sprintf(strType, "Unknow type");
break;
}
printf("%s - %s\n", TmpDrive, strType);
}
}
if ( Buf[i])
TmpDrive[j++] = Buf[i];
if ( Buf[i] == 0 && Buf[i+1] == 0 && Buf[i+2] == 0)
return 0;
}
return 0;
}
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