Microsoft KB Archive/253650

Knowledge Base

HOWTO: Use the SysInfo ActiveX Control in Visual FoxPro

Article ID: 253650

Article Last Modified on 7/13/2004

---

APPLIES TO

• Microsoft Visual FoxPro 6.0 Professional Edition

---

This article was previously published under Q253650

SUMMARY

The SysInfo control allows you to respond to certain system messages sent to all applications by the operating system. Your application can then adapt to changes in the operating system if necessary. This article demonstrates how to create a form in Visual FoxPro with the SysInfo control to respond to changes.

MORE INFORMATION

To create the sample, follow these steps:

1. Create a program called mySystem.prg by using the following code:

   PUBLIC oform
   
   oform=createOBJECT("frmSysInfo")
   oform.Show
   Read Events
   RETURN
   
       **************************************************
   *-- Form:         frmSysinfo 
   *-- ParentClass:  form
   *-- BaseClass:    form
   *
   DEFINE CLASS frmSysinfo AS form
   
       Top = -8
       Left = 16
       Height = 323
       Width = 271
       DoCreate = .T.
       Caption = "Your system Information"
       Name = "frmSysInfo"
       
       ADD OBJECT lblOSNameTag AS label WITH ;
           AutoSize = .T., ;
           Caption = "Operating System:", ;
           Height = 17, ;
           Left = 12, ;
           Top = 21, ;
           Width = 103, ;
           Name = "lblOSNameTag"
   
       ADD OBJECT lblOSBuildTag AS label WITH ;
           AutoSize = .T., ;
           Caption = "Build #:", ;
           Height = 17, ;
           Left = 72, ;
           Top = 69, ;
           Width = 43, ;
           Name = "lblOSBuildTag"
   
       ADD OBJECT lblOSVersionTag AS label WITH ;
           AutoSize = .T., ;
           Caption = "Version #:", ;
           Height = 17, ;
           Left = 58, ;
           Top = 45, ;
           Width = 57, ;
           Name = "lblOSVersionTag"
   
       ADD OBJECT lblversion AS label WITH ;
           AutoSize = .T., ;
           FontBold = .T., ;
           Caption = "", ;
           Height = 17, ;
           Left = 132, ;
           Top = 45, ;
           Width = 2, ;
           ForeColor = RGB(0,0,128), ;
           Name = "lblVersion"
   
       ADD OBJECT lblbuild AS label WITH ;
           AutoSize = .T., ;
           FontBold = .T., ;
           Caption = "", ;
           Height = 17, ;
           Left = 132, ;
           Top = 69, ;
           Width = 2, ;
           ForeColor = RGB(0,0,128), ;
           Name = "lblBuild"
   
       ADD OBJECT lblos AS label WITH ;
           AutoSize = .T., ;
           FontBold = .T., ;
           Caption = "", ;
           Height = 17, ;
           Left = 132, ;
           Top = 21, ;
           Width = 2, ;
           ForeColor = RGB(0,0,128), ;
           Name = "lblOs"
   
       ADD OBJECT lblSysCngTag AS label WITH ;
           AutoSize = .T., ;
           Caption = "System Change Log", ;
           Height = 17, ;
           Left = 12, ;
           Top = 96, ;
           Width = 114, ;
           Name = "lblSysCngTag"
   
       ADD OBJECT edtlog AS editbox WITH ;
           Height = 100, ;
           Left = 12, ;
           Top = 120, ;
           Width = 253, ;
           Name = "edtLog"
   
       ADD OBJECT edttime AS editbox WITH ;
           Height = 64, ;
           Left = 12, ;
           Top = 252, ;
           Width = 253, ;
           Name = "edtTime"
   
       ADD OBJECT lblSysTimeTag AS label WITH ;
           AutoSize = .T., ;
           Caption = "System Time Change Message", ;
           Height = 17, ;
           Left = 12, ;
           Top = 228, ;
           Width = 175, ;
           Name = "lblSysTimeTag"
   
       ADD OBJECT olesysinfo AS olecontrol WITH ;
           OleClass="SYSINFO.sysinfo.1", ;
           Top = 240, ;
           Left = 288, ;
           Height = 100, ;
           Width = 100, ;
           Visible = .F., ;
           Name = "oleSysinfo"
   
            PROCEDURE Unload
           clear events
       ENDPROC
   
       PROCEDURE olesysinfo.SettingChanged
           *** ActiveX Control Event ***
           LPARAMETERS item
   
           If !Empty(Thisform.edtLog.value)
               Thisform.edtLog.value = Thisform.edtLog.value + ;
                   chr(10) + chr(13) + "System Change - " + ttoc(DateTime()) + ;
                   " " + Alltrim(str(Item))
           else
               Thisform.edtLog.value = "System Change - " + ttoc(DateTime()) + ;
                   " " + Alltrim(str(Item))
           endif
       ENDPROC
   
       PROCEDURE olesysinfo.TimeChanged
           *** ActiveX Control Event ***
           Thisform.edtTime.Value = ""
           Thisform.edtTime.Value = "The System Time has been Changed!"
           Thisform.edtTime.Value = Thisform.edtTime.Value + chr(10)
           Thisform.edtTime.Value = Thisform.edtTime.Value + ;
               "Put any information in this event to warn of changes"
       ENDPROC
   
       PROCEDURE olesysinfo.Init
           Private vpOsPlatform
           Do Case
               case This.OsPlatform = 0
                   vpOsPlatform = "Win32s"
   
               case This.OsPlatform = 1
                   vpOsPlatform = "Windows 98"
   
               case This.OsPlatform = 2 and THis.OSVersion >= 5
                   vpOsPlatform = "Windows 2000"
   
               Otherwise
                   vpOsPlatform = "Windows NT"
           EndCase
   
           Thisform.lblOs.Caption = vpOsPlatform
           Thisform.lblVersion.Caption = Alltrim(str(This.OSVersion))
           Thisform.lblBuild.Caption = Alltrim(str(This.OSBuild))
       ENDPROC
   
   ENDDEFINE
   
   *
   *-- EndDefine: form1
   **************************************************
                       

2. Save and run mySystem.prg.
3. While the form is visible, adjust the size of your Windows taskbar. Note the information displayed in the "System Change Log."
4. Double-click on the clock in the taskbar. Change the System time. Note the information entered in the box labeled "System Time Change Message."

This can be very useful when your application needs to get specific information about the operating system that it is running on. In this article, the specific examples can be applied to the other events and properties in the SysInfo control.

The SysInfo control can provide information on and detect the following system events:

• Hardware Device Profile Changes
• Plug and Play Hardware events (Device adding and removal)
• System Wide Parameter Changes (that is, Keyboard default Language Changes)
• System Color Changes
• Display Property Changes
• System Time Changes

Other events can be monitored and acted upon using this control. Check the control's Help file for a complete list of the properties and events.

REFERENCES

For additional information regarding ActiveX Controls supported with MicrosoftVisual FoxPro 6.0, click the article number below to view the article in the Microsoft Knowledge Base:

191222 INFO: ActiveX Controls Supported by Visual FoxPro 6.0

Keywords: kbhowto kbcodesnippet kbctrl KB253650

---

Send feedback to Microsoft

© Microsoft Corporation. All rights reserved.