请问Delphi下如何使用GetVolumeInformation()?

Question

我不懂得应该怎样设置入参，请帮帮忙，谢谢！

Answer 1

type
   VolumeInfoRecord = record
     RootPathName:           string;
     VolumeName:             string;
     VolumeSerialNumber:     string;
     MaxComponentLength:     DWORD;
     FileSystemFlags:        DWORD;
     FileSystemName:         string;
   end;var
  VolumeInfoRec: VolumeInfoRecord;
  VolumeNameBuffer: PChar;
  VolumeNameSize: DWORD;
  FileSystemNameBuffer: PChar;
  FileSystemNameSize: DWORD;
  VolSerial: DWORD;
  BufLen : DWORD;
  RPName :String;
begin
  RPName :='C:\'; //可自己修改
  BufLen := MAX_PATH + 1;
  GetMem(VolumeNameBuffer, BufLen);
  GetMem(FileSystemNameBuffer, BufLen);
  try
    with VolumeInfoRec do begin
      VolumeNameSize := BufLen;
      FileSystemNameSize := BufLen;      // Get volume info with no automatic error
      SetErrorMode(SEM_NOOPENFILEERRORBOX);
      if GetVolumeInformation(PChar(RPName),
                              VolumeNameBuffer,
                              VolumeNameSize,
                              @VolSerial,
                              MaxComponentLength,
                              FileSystemFlags,
                              FileSystemNameBuffer,
                              FileSystemNameSize) then begin
         //
         RootPathName       := RPName;
         VolumeName         := StrPas(VolumeNameBuffer);
         VolumeSerialNumber := IntToHex(HiWord(VolSerial), 4) + '-' +
                               IntToHex(LoWord(VolSerial), 4);
         FileSystemName     := StrPas(FileSystemNameBuffer);
  finally
    FreeMem(VolumeNameBuffer);
    FreeMem(FileSystemNameBuffer);
  end; // try
end;

Answer 2

oracle_lover:
    我在编译是为什么老提示finally处出错，请问finally有什么用处？

Answer 3

编译出错？什么错误？
finally
    FreeMem(VolumeNameBuffer);
    FreeMem(FileSystemNameBuffer);
的作用是无论前面的操作是否成功，最终都释放这两个变量占用的内存。因为这两个变量的内存是手动分配的，系统无法自动回收。