z这个函数怎么调用

var
  _GetVolumeNameForVolumeMountPoint: function (lpszVolumeMountPoint: LPCSTR; lpszVolumeName: LPSTR; cchBufferLength: DWORD): BOOL; stdcall;
  _SetVolumeMountPoint: function (lpszVolumeMountPoint: LPCSTR; lpszVolumeName: LPCSTR): BOOL; stdcall;
  _DeleteVolumeMountPoint: function (lpszVolumeMountPoint: LPCSTR): BOOL; stdcall;function GetVolumeNameForVolumeMountPoint(lpszVolumeMountPoint: LPCSTR; lpszVolumeName: LPSTR; cchBufferLength: DWORD): BOOL;
var
  Kernel32: THandle;
begin
  if not Assigned(_GetVolumeNameForVolumeMountPoint) then
  begin
    Kernel32 := GetModuleHandle(PChar('kernel32.dll'));
    if Kernel32 <> 0 then @_GetVolumeNameForVolumeMountPoint := GetProcAddress(Kernel32, PChar('GetVolumeNameForVolumeMountPointA'));
  end;
  if Assigned(_GetVolumeNameForVolumeMountPoint) then
    Result := _GetVolumeNameForVolumeMountPoint(lpszVolumeMountPoint, lpszVolumeName, cchBufferLength)
  else
    Result := False;
end;function SetVolumeMountPoint(lpszVolumeMountPoint: LPCSTR; lpszVolumeName: LPCSTR): BOOL;
var
  Kernel32: THandle;
begin
  if not Assigned(_SetVolumeMountPoint) then
  begin
    Kernel32 := GetModuleHandle(PChar('kernel32.dll'));
    if Kernel32 <> 0 then @_SetVolumeMountPoint := GetProcAddress(Kernel32, PChar('SetVolumeMountPointA'));
  end;
  if Assigned(_SetVolumeMountPoint) then
    Result := _SetVolumeMountPoint(lpszVolumeMountPoint, lpszVolumeName)
  else
    Result := False;
end;function DeleteVolumeMountPoint(lpszVolumeMountPoint: LPCSTR): BOOL;
var
  Kernel32: THandle;
begin
  if not Assigned(_DeleteVolumeMountPoint) then
  begin
    Kernel32 := GetModuleHandle(PChar('kernel32.dll'));
    if Kernel32 <> 0 then @_DeleteVolumeMountPoint := GetProcAddress(Kernel32, PChar('DeleteVolumeMountPointA'));
  end;
  if Assigned(_DeleteVolumeMountPoint) then
    Result := _DeleteVolumeMountPoint(lpszVolumeMountPoint)
  else
    Result := False;
end;
我不知道他的参数是什么