Bagaimana untuk mengubah zona waktu informasi dengan menggunakan Visual Basic

Hal ini kadang-kadang diperlukan untuk pemrograman mengubah zona waktu sistem di mana aplikasi berjalan. Artikel ini menunjukkan teknik ini.

Cara untuk menerapkan efek ini adalah sebagai berikut:

1. Menentukan zona waktu yang Anda ingin mengubah.
2. Cari kunci registri yang berisi informasi yang diperlukan untuk mengisi struktur TIME_ZONE_INFORMATION.
3. Membaca dalam informasi dan letakkan nilai variabel tipe TIME_ZONE_INFORMATION.
4. Panggilan API SetTimeZoneInformation, melewati TIME_ZONE_INFORMATION struct variabel.

Lokasi di registri yang berisi informasi zona waktu berbeda antara Windows 9 x dan Windows NT/Windows 2000.

Untuk Windows NT dan Windows 2000, kota ini terletak di: Untuk Windows 9 x, itu terletak di: Nama kunci zona waktu berbeda antara Windows NT, Windows 2000 dan Windows 9 x juga karena Windows NT dan Windows 2000 menambahkan string "Waktu standar" untuk kunci berbeda sedangkan Windows 9 x tidak.

Misalnya:

Dalam Windows NT dan Windows 2000, Anda akan melihat kunci ini:
Sementara di Windows 9 x, Anda akan melihat kunci ini:Lokasi registri di mana pengaturan tanggal saat ini dapat ditemukan adalah:

Contoh langkah demi langkah

Contoh kode di bawah ini memerlukan bentuk dengan suatu listbox. Listbox penuh dengan nilai-nilai zona waktu mungkin bahwa pengguna dapat memilih dengan klik dua kali untuk mengubah zona waktu. Ini akan menunjukkan messagebox yang pernah dipecat, akan mengubah pengaturan sistem kembali ke nilai-nilai asli mereka.

1. Buat projek Standard EXE yang baru. Form1 dibuat secara default.
2. Menambahkan sebuah Listbox DNS untuk Form1.
3. Tambahkan kode berikut ke bagian umum Deklarasi Form1:

   Option Explicit
   
   ' Operating System version information declares
   
   Private Const VER_PLATFORM_WIN32_NT = 2
   Private Const VER_PLATFORM_WIN32_WINDOWS = 1
   
   Private Type OSVERSIONINFO
           dwOSVersionInfoSize As Long
           dwMajorVersion As Long
           dwMinorVersion As Long
           dwBuildNumber As Long
           dwPlatformId As Long
           szCSDVersion As String * 128 ' Maintenance string
   End Type
   
   Private Declare Function GetVersionEx Lib "kernel32" _
   Alias "GetVersionExA" (lpVersionInformation As OSVERSIONINFO) As Long
   
   ' Time Zone information declares
   
   Private Type SYSTEMTIME
      wYear As Integer
      wMonth As Integer
      wDayOfWeek As Integer
      wDay As Integer
      wHour As Integer
      wMinute As Integer
      wSecond As Integer
      wMilliseconds As Integer
   End Type
   
   Private Type REGTIMEZONEINFORMATION
      Bias As Long
      StandardBias As Long
      DaylightBias As Long
      StandardDate As SYSTEMTIME
      DaylightDate As SYSTEMTIME
   End Type
   
   Private Type TIME_ZONE_INFORMATION
      Bias As Long
      StandardName(0 To 63) As Byte ' used to accommodate Unicode strings
      StandardDate As SYSTEMTIME
      StandardBias As Long
      DaylightName(0 To 63) As Byte ' used to accommodate Unicode strings
      DaylightDate As SYSTEMTIME
      DaylightBias As Long
   End Type
   
   Private Const TIME_ZONE_ID_INVALID = &HFFFFFFFF
   Private Const TIME_ZONE_ID_UNKNOWN = 0
   Private Const TIME_ZONE_ID_STANDARD = 1
   Private Const TIME_ZONE_ID_DAYLIGHT = 2
   
   Private Declare Function GetTimeZoneInformation Lib "kernel32" _
   (lpTimeZoneInformation As TIME_ZONE_INFORMATION) As Long
   
   Private Declare Function SetTimeZoneInformation Lib "kernel32" _
   (lpTimeZoneInformation As TIME_ZONE_INFORMATION) As Long
   
   ' Registry information declares
   Private Const REG_SZ As Long = 1
   Private Const REG_BINARY = 3
   Private Const REG_DWORD As Long = 4
   
   Private Const HKEY_CLASSES_ROOT = &H80000000
   Private Const HKEY_CURRENT_USER = &H80000001
   Private Const HKEY_LOCAL_MACHINE = &H80000002
   Private Const HKEY_USERS = &H80000003
   
   Private Const ERROR_SUCCESS = 0
   Private Const ERROR_BADDB = 1
   Private Const ERROR_BADKEY = 2
   Private Const ERROR_CANTOPEN = 3
   Private Const ERROR_CANTREAD = 4
   Private Const ERROR_CANTWRITE = 5
   Private Const ERROR_OUTOFMEMORY = 6
   Private Const ERROR_ARENA_TRASHED = 7
   Private Const ERROR_ACCESS_DENIED = 8
   Private Const ERROR_INVALID_PARAMETERS = 87
   Private Const ERROR_NO_MORE_ITEMS = 259
   
   Private Const KEY_ALL_ACCESS = &H3F
   
   Private Const REG_OPTION_NON_VOLATILE = 0
   
   Private Declare Function RegOpenKeyEx Lib "advapi32.dll" _
      Alias "RegOpenKeyExA" ( _
      ByVal hKey As Long, _
      ByVal lpSubKey As String, _
      ByVal ulOptions As Long, _
      ByVal samDesired As Long, _
      phkResult As Long) _
   As Long
   
   Private Declare Function RegQueryValueEx Lib "advapi32.dll" _
      Alias "RegQueryValueExA" ( _
      ByVal hKey As Long, _
      ByVal lpszValueName As String, _
      ByVal lpdwReserved As Long, _
      lpdwType As Long, _
      lpData As Any, _
      lpcbData As Long) _
   As Long
   
   Private Declare Function RegQueryValueExString Lib "advapi32.dll" _
      Alias "RegQueryValueExA" ( _
      ByVal hKey As Long, _
      ByVal lpValueName As String, _
      ByVal lpReserved As Long, _
      lpType As Long, _
      ByVal lpData As String, _
      lpcbData As Long) _
   As Long
   
   Private Declare Function RegEnumKey Lib "advapi32.dll" _
      Alias "RegEnumKeyA" ( _
      ByVal hKey As Long, _
      ByVal dwIndex As Long, _
      ByVal lpName As String, _
      ByVal cbName As Long) _
   As Long
   
   Private Declare Function RegCloseKey Lib "advapi32.dll" ( _
      ByVal hKey As Long) _
   As Long
   
   ' Registry Constants
   Const SKEY_NT = "SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones"
   Const SKEY_9X = "SOFTWARE\Microsoft\Windows\CurrentVersion\Time Zones"
   
   ' The following declaration is different from the one in the API viewer.
   ' To disable implicit ANSI<->Unicode conversion, it changes the 
   ' variable types of lpMultiByteStr and lpWideCharStr to Any.
   '
   Private Declare Function MultiByteToWideChar Lib "kernel32" ( _
       ByVal CodePage As Long, _
       ByVal dwFlags As Long, _
       lpMultiByteStr As Any, _
       ByVal cchMultiByte As Long, _
       lpWideCharStr As Any, _
       ByVal cchWideChar As Long) As Long
       
   ' The above Declare and the following Constants are used to make
   ' this sample compatible with Double Byte Character Systems (DBCS).
   Private Const CP_ACP = 0
   Private Const MB_PRECOMPOSED = &H1
   Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" ( _ 
   ByRef Destination As Any, _
   ByRef Source As Any, _
   ByVal numbytes As Long)
   Dim SubKey As String
   
   Private Sub Form_Load()
      Dim lRetVal As Long, lResult As Long, lCurIdx As Long
      Dim lDataLen As Long, lValueLen As Long, hKeyResult As Long
      Dim strvalue As String
      Dim osV As OSVERSIONINFO
   
   ' Win9x and WinNT have a slightly different registry structure. Determine
   ' the operating system and set a module variable to the correct subkey.
   
      osV.dwOSVersionInfoSize = Len(osV)
      Call GetVersionEx(osV)
      If osV.dwPlatformId = VER_PLATFORM_WIN32_NT Then
         SubKey = SKEY_NT
      Else
         SubKey = SKEY_9X
      End If
   
      lRetVal = RegOpenKeyEx(HKEY_LOCAL_MACHINE, SubKey, 0, _
                             KEY_ALL_ACCESS, hKeyResult)
   
      If lRetVal = ERROR_SUCCESS Then
   
         lCurIdx = 0
         lDataLen = 32
         lValueLen = 32
   
         Do
            strvalue = String(lValueLen, 0)
            lResult = RegEnumKey(hKeyResult, lCurIdx, strvalue, lDataLen)
   
            If lResult = ERROR_SUCCESS Then
               List1.AddItem Left(strvalue, lValueLen)
            End If
   
            lCurIdx = lCurIdx + 1
   
         Loop While lResult = ERROR_SUCCESS
   
         RegCloseKey hKeyResult
      Else
         List1.AddItem "Could not open registry key"
      End If
   End Sub
   
   Private Sub List1_DblClick()
      Dim TZ As TIME_ZONE_INFORMATION, oldTZ As TIME_ZONE_INFORMATION
      Dim rTZI As REGTIMEZONEINFORMATION
      Dim bytDLTName(32) As Byte, bytSTDName(32) As Byte
      Dim cbStr As Long, dwType As Long
      Dim lRetVal As Long, hKeyResult As Long, lngData As Long
   
      lRetVal = RegOpenKeyEx(HKEY_LOCAL_MACHINE, SubKey & "\" & List1.Text, _
                              0, KEY_ALL_ACCESS, hKeyResult)
   
      If lRetVal = ERROR_SUCCESS Then
         lRetVal = RegQueryValueEx(hKeyResult, "TZI", 0&, ByVal 0&, _
                                     rTZI, Len(rTZI))
   
         If lRetVal = ERROR_SUCCESS Then
            TZ.Bias = rTZI.Bias
            TZ.StandardBias = rTZI.StandardBias
            TZ.DaylightBias = rTZI.DaylightBias
            TZ.StandardDate = rTZI.StandardDate
            TZ.DaylightDate = rTZI.DaylightDate
   
            cbStr = 32
            dwType = REG_SZ
   
            lRetVal = RegQueryValueEx(hKeyResult, "Std", _
                        0&, dwType, bytSTDName(0), cbStr)
   
            If lRetVal = ERROR_SUCCESS Then
               Call MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, _
                  bytSTDName(0), cbStr, TZ.StandardName(0), 32)
            Else
               RegCloseKey hKeyResult
               Exit Sub
            End If
   
            cbStr = 32
            dwType = REG_SZ
   
            lRetVal = RegQueryValueEx(hKeyResult, "Dlt", _
                        0&, dwType, bytDLTName(0), cbStr)
   
            If lRetVal = ERROR_SUCCESS Then
               Call MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, _
                  bytDLTName(0), cbStr, TZ.DaylightName(0), 32)
            Else
               RegCloseKey hKeyResult
               Exit Sub
            End If
   
            lRetVal = GetTimeZoneInformation(oldTZ)
   
            If lRetVal = TIME_ZONE_ID_INVALID Then
               MsgBox "Error getting original TimeZone Info"
               RegCloseKey hKeyResult
               Exit Sub
            Else
            If TZ.DaylightDate.wMonth <> 0 And TZ.DaylightBias <> 0 Then
               lRetVal = SetTimeZoneInformation(TZ)
            Else
              Call CopyMemory(TZ.DaylightName(0), TZ.StandardName(0), 64)
              TZ.DaylightBias = 0
              lRetVal = SetTimeZoneInformation(TZ)
            End If
               MsgBox "Time Zone Changed, Click OK to restore"
               lRetVal = SetTimeZoneInformation(oldTZ)
            End If
         End If
   
         RegCloseKey hKeyResult
      End If
   End Sub
   					

4. Menjalankan program, dan perhatikan bahwa listbox menampilkan semua zona waktu yang tersedia.
5. Pilih zona waktu, dan kemudian klik dua kali itu. Lokal sistem Anda berubah menjadi zona yang dipilih. Anda menerima pesan berikut ini:
   Zona waktu berubah, klik OK untuk memulihkan
6. Di Panel kontrol, klik dua kali Tanggal/waktu ikon. Anda juga dapat mencapai dialog ini dengan mengklik dua kali jam di system tray. Klik Zona waktu tab dan mengamati bahwa zona waktu telah berubah.
7. Dekat Tanggal/waktu properti kotak dialog dan klik Oke pada kotak pesan ditampilkan oleh aplikasi Anda. Ulangi langkah sebelumnya untuk memastikan bahwa informasi zona waktu telah dipulihkan.