HOWTO: Get Windows Status Information via API Calls

• Microsoft Visual Basic Control Creation, Learning, Professional, and Enterprise Editions, for Windows, version 5.0

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.
• Memory information for total physical memory, available physical memory, total virtual memory, and available virtual memory.

MORE INFORMATION

Steps to Create Example Program

1. Start Visual Basic 5.0 and select Standard EXE. If Visual Basic 5.0 is already running, click New Project on the File menu, and select Standard EXE. Form1 is created by default.

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

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

         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
   
   

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

         Private Sub Form_Load()
            Dim msg As String         ' Status information.
   
            Show
            MousePointer = 11   ' Hourglass.
   
                ' Get operating system and version.
                Dim verinfo As OSVERSIONINFO
                Dim build As String, ver_major As String, ver_minor As String
                Dim ret As Long
                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 & ")" & vbCrLf & vbCrLf
   
                ' 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" & vbCrLf
                    Case PROCESSOR_INTEL_486
                        msg = msg & "Intel 486" & vbCrLf
                    Case PROCESSOR_INTEL_PENTIUM
                        msg = msg & "Intel Pentium" & vbCrLf
                    Case PROCESSOR_MIPS_R4000
                        msg = msg & "MIPS R4000" & vbCrLf
                    Case PROCESSOR_ALPHA_21064
                        msg = msg & "DEC Alpha 21064" & vbCrLf
                    Case Else
                        msg = msg & "(unknown)" & vbCrLf
   
                End Select
                msg = msg & vbCrLf
                ' Get free memory.
                Dim memsts As MEMORYSTATUS
                Dim memory As Long
                GlobalMemoryStatus memsts
                memory = memsts.dwTotalPhys
                msg = msg & "Total Physical Memory: "
                msg = msg & Format$(memory \ 1024, "###,###,###") & "K" _
                          & vbCrLf
                memory& = memsts.dwAvailPhys
                msg = msg & "Available Physical Memory: "
                msg = msg & Format$(memory \ 1024, "###,###,###") & "K" _
                          & vbCrLf
                memory& = memsts.dwTotalVirtual
                msg = msg & "Total Virtual Memory: "
                msg = msg & Format$(memory \ 1024, "###,###,###") & "K" _
                          & vbCrLf
                memory& = memsts.dwAvailVirtual
                msg = msg & "Available Virtual Memory: "
                msg = msg & Format$(memory \ 1024, "###,###,###") & "K" _
                          & vbCrLf & vbCrLf
   
            Print msg
            MousePointer = 0
         End Sub
   
   

5. On the Run menu, click Start, or press the F5 key to start the program. Pass the cursor over each button to display the ToolTip describing the button's function. Click the button to perform the function.