nt中的关闭计算机，重新登录的实现.txt

自己对DELPHI学习的一点体会

NT中的关闭计算机，重新登录的实现 (2001年5月12日) 

本站更新  分类:系统   作者:tomm  推荐:   阅读次数:172  
(http://www.codesky.net)  

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在NT中要实现以上的功能，首先必须获得SE_SHUTDOWN_NAME权限后，才能调用ExitWindowsEx；这是和Windows95的不同
//iFlags:
// one of the following must be specified
// EWX_LOGOFF
// EWX_REBOOT
// EWX_SHUTDOWN
// following attributes may be combined with above flags
// EWX_POWEROFF
// EWX_FORCE : terminate processes
function WinExitInNT( iFlags : integer ) : boolean;
begin
Result := True;
if( SetPrivilege( 'SeShutdownPrivilege', True ) )then
begin
if( not ExitWindowsEx( iFlags, 0 ) )then
begin
Result := False;
end;
SetPrivilege( 'SeShutdownPrivilege', False )
end 
else begin
// handle errors...
Result := False;
end;
end;

//Enabled or DisEnabled the SE_SHUTDOWN_NAME privilege
//sPrivilegeName:
// 'SE_SHUTDOWN_NAME'
//bEnabled :
// Enabled or DisEnabled 'SE_SHUTDOWN_NAME' privilege
function SetPrivilege(sPrivilegeName : string;
bEnabled : boolean )
: boolean;
var
TPPrev,
TP : TTokenPrivileges;
Token : THandle;
dwRetLen : DWord;
begin
Result := False;

//opens the access token associated with a process. 
OpenProcessToken(
GetCurrentProcess, //handle to process
TOKEN_ADJUST_PRIVILEGES //Required to change the privileges specified in an access token.
or TOKEN_QUERY, //Required to query the contents of an access token.
Token);

TP.PrivilegeCount := 1;
//retrieves the locally unique identifier (LUID) used on a specified system to 
//locally represent the specified privilege name. 
if( LookupPrivilegeValue(
Nil, //attempts to find the privilege name on the local system.
PChar( sPrivilegeName ), // address of string specifying the privilege
TP.Privileges[ 0 ].LUID ) // address of locally unique identifier
)then
begin
if( bEnabled )then //Give this privileges
begin
TP.Privileges[ 0 ].Attributes := SE_PRIVILEGE_ENABLED;
end
else begin //NOT Give this privileges
TP.Privileges[ 0 ].Attributes := 0;
end;

dwRetLen := 0;
//enables or disables privileges in the specified access token.
Result := AdjustTokenPrivileges(
Token, // handle to token that contains privileges
False, //modifies privileges
TP, // pointer to new privilege information
SizeOf( TPPrev ), // size, in bytes, of the TPPrev buffer
TPPrev, // receives original state of changed privileges
dwRetLen // receives required size of the TPPrev buffer
);
end;

CloseHandle( Token );
end;