How VB Can Get Windows Status Information via API Calls

- Standard, Professional, and Enterprise Editions of Microsoft

  Visual Basic, 16-bit and 32-bit, for Windows, version 4.0

SUMMARY

The Visual Basic for Windows sample program below demonstrates how you can obtain system status information similar to the information displayed in the Windows Program Manager About box. The sample program displays the following information using the Windows API functions indicated:

• The Windows version number with the GetVersion function.
• The CPU processor type.
• Whether Windows is running in enhanced mode or standard mode on a 16-bit operating system. This does not apply to Microsoft Windows 95 or Microsoft Windows NT.
• The amount of free memory.
• The percentage of free system resources with SystemHeapInfo on a 16-bit operating system. This does not apply to Microsoft Windows 95 or Microsoft Windows NT.

      3.1 and is not available in Microsoft Windows, version 3.0. All other
      API functions listed above are available in both Windows versions 3.0
      or 3.1.

MORE INFORMATION

Steps to Create Example Program

1. Run Visual Basic for Windows, or if Visual Basic for Windows is already running, click New Project on the File menu (press ALT, F, N). Form1 is created by default.

2. On the File menu, click Add Module (press ALT, F, M). Module1 is created by default.

3. Enter the following code into the General Declarations section of a code module:

   #If Win32 Then

          Type SYSTEM_INFO
                  dwOemID As Long
                  dwPageSize As Long
                  lpMinimumApplicationAddress As Long
                  lpMaximumApplicationAddress As Long
                  dwActiveProcessorMask As Long
                  dwNumberOrfProcessors As Long
                  dwProcessorType As Long
                  dwAllocationGranularity As Long
                  dwReserved As Long
          End Type
          Type OSVERSIONINFO
                  dwOSVersionInfoSize As Long
                  dwMajorVersion As Long
                  dwMinorVersion As Long
                  dwBuildNumber As Long
                  dwPlatformId As Long
                  szCSDVersion As String * 128
          End Type
          Type MEMORYSTATUS
                  dwLength As Long
                  dwMemoryLoad As Long
                  dwTotalPhys As Long
                  dwAvailPhys As Long
                  dwTotalPageFile As Long
                  dwAvailPageFile As Long
                  dwTotalVirtual As Long
                  dwAvailVirtual As Long
          End Type
   
          Declare Function GetVersionEx Lib "kernel32" Alias "GetVersionExA" _
             (LpVersionInformation As OSVERSIONINFO) As Long
          Declare Sub GlobalMemoryStatus Lib "kernel32" (lpBuffer As _
             MEMORYSTATUS)
          Declare Sub GetSystemInfo Lib "kernel32" (lpSystemInfo As _
             SYSTEM_INFO)
   
          Public Const PROCESSOR_INTEL_386 = 386
          Public Const PROCESSOR_INTEL_486 = 486
          Public Const PROCESSOR_INTEL_PENTIUM = 586
          Public Const PROCESSOR_MIPS_R4000 = 4000
          Public Const PROCESSOR_ALPHA_21064 = 21064
      #Else
         ' Constants for GetWinFlags.
         Global Const WF_CPU286 = &H2
         Global Const WF_CPU386 = &H4
         Global Const WF_CPU486 = &H8
         Global Const WF_80x87 = &H400
         Global Const WF_STANDARD = &H10
         Global Const WF_ENHANCED = &H20
         Global Const WF_WINNT = &H4000
   
         ' Type for SystemHeapInfo.
         Type SYSHEAPINFO
            dwSize As Long
            wUserFreePercent As Integer
            wGDIFreePercent As Integer
            hUserSegment As Integer
            hGDISegment As Integer
         End Type
   
         Declare Function GetVersion Lib "kernel" () As Long
         Declare Function GetWinFlags Lib "kernel" () As Long
         'Enter each of the following Declare statements as one, single line:
         Declare Function GetFreeSpace Lib "kernel" (ByVal wFlags As Integer)_
            As Long
         Declare Function GlobalCompact Lib "kernel" _
            (ByVal dwMinFree As Long) As Long
         Declare Function SystemHeapInfo Lib "toolhelp.dll" _
            (shi As SYSHEAPINFO) As Integer
      #End If
   
   

4. Enter the following code into the Form_Load procedure of Form1:

      Private Sub Form_Load()
         Dim msg As String         ' Status information.
         Dim nl As String          ' New-line.
         nl = Chr$(13) + Chr$(10)  ' New-line.
   
         Show
         MousePointer = 11   ' Hourglass.
   
         #If Win32 Then
             ' Get operating system and version.
             Dim verinfo As OSVERSIONINFO
             verinfo.dwOSVersionInfoSize = Len(verinfo)
             ret% = GetVersionEx(verinfo)
             If ret% = 0 Then
                 MsgBox "Error Getting Version Information"
                 End
             End If
             Select Case verinfo.dwPlatformId
                 Case 0
                     msg = msg + "Windows 32s "
                 Case 1
                     msg = msg + "Windows 95 "
                 Case 2
                     msg = msg + "Windows NT "
             End Select
   
             ver_major$ = verinfo.dwMajorVersion
             ver_minor$ = verinfo.dwMinorVersion
             build$ = verinfo.dwBuildNumber
             msg = msg + ver_major$ + "." + ver_minor$
             msg = msg + " (Build " + build$ + ")" + nl + nl
   
             ' Get CPU type and operating mode.
             Dim sysinfo As SYSTEM_INFO
             GetSystemInfo sysinfo
             msg = msg + "CPU: "
             Select Case sysinfo.dwProcessorType
                 Case PROCESSOR_INTEL_386
                     msg = msg + "Intel 386" + nl
                 Case PROCESSOR_INTEL_486
                     msg = msg + "Intel 486" + nl
                 Case PROCESSOR_INTEL_PENTIUM
                     msg = msg + "Intel Pentium" + nl
                 Case PROCESSOR_MIPS_R4000
                     msg = msg + "MIPS R4000" + nl
                 Case PROCESSOR_ALPHA_21064
                     msg = msg + "DEC Alpha 21064" + nl
                 Case Else
                     msg = msg + "(unknown)" + nl
   
             End Select
             msg = msg + nl
             ' Get free memory.
             Dim memsts As MEMORYSTATUS
             Dim memory&
             GlobalMemoryStatus memsts
             memory& = memsts.dwTotalPhys
             msg = msg + "Total Physical Memory: "
             msg = msg + Format$(memory& \ 1024, "###,###,###") + "K" + nl
             memory& = memsts.dwAvailPhys
             msg = msg + "Available Physical Memory: "
             msg = msg + Format$(memory& \ 1024, "###,###,###") + "K" + nl
             memory& = memsts.dwTotalVirtual
             msg = msg + "Total Virtual Memory: "
             msg = msg + Format$(memory& \ 1024, "###,###,###") + "K" + nl
             memory& = memsts.dwAvailVirtual
             msg = msg + "Available Virtual Memory: "
             msg = msg + Format$(memory& \ 1024, "###,###,###") + "K" + nl _
                  + nl
   
             ' Get free system resources.
             ' Not applicable to 32-bit operating system (Windows NT).
         #Else
             ' Get operating system and version.
             ver& = GetVersion()
             status& = GetWinFlags()
   
             If status& And WF_WINNT Then
                 msg = msg + "Microsoft Windows NT "
             Else
                 msg = msg + "Microsoft Windows "
             End If
             ver_major$ = Format$(ver& And &HFF)
             ver_minor$ = Format$(ver& \ &H100, "00")
             msg = msg + ver_major$ + "." + ver_minor$ + nl
   
             ' Get CPU type and operating mode.
             msg = msg + "CPU: "
             If status& And WF_CPU286 Then msg = msg + "80286"
             If status& And WF_CPU386 Then msg = msg + "80386"
             If status& And WF_CPU486 Then msg = msg + "80486"
             If status& And WF_80x87 Then msg = msg + " with 80x87"
             msg = msg + nl
             msg = msg + "Mode: "
             If status& And WF_STANDARD Then msg = msg + "Standard" + nl
             If status& And WF_ENHANCED Then msg = msg + "Enhanced" + nl
   
             ' Get free memory.
             memory& = GetFreeSpace(0)
             msg = msg + "Memory free: "
             msg = msg + Format$(memory& \ 1024, "###,###,###") + "K" + nl
             memory& = GlobalCompact(&HFFFFFFFF)
             msg = msg + "Largest free block: "
             msg = msg + Format$(memory& \ 1024, "###,###,###") + "K" + nl
   
             ' Get free system resources.
             ' The SystemHeapInfo API function became available in Windows
             '  version 3.1.
             msg = msg + "System resources: "
             If ver& >= &H310 Then
                 Dim shi As SYSHEAPINFO
                 shi.dwSize = Len(shi)
                 If SystemHeapInfo(shi) Then
                     If shi.wUserFreePercent < shi.wGDIFreePercent Then
                         msg = msg + Format$(shi.wUserFreePercent) + "%"
                     Else
                         msg = msg + Format$(shi.wGDIFreePercent) + "%"
                     End If
                 End If
             Else
                 msg = msg + "n/a"
             End If
         #End If
         MsgBox msg, 0, "About " + Caption
         MousePointer = 0
      End Sub
   
   

5. Press the F5 key to run the program.