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How to work with WMI services to access Windows advanced functionality

WMI is a very useful interface accessible through DesktopX via scripting to retrieve all sort of information from the operating system. It opens the door for new useful widgets.
You can find here the full MSDN documentation, in particular the introduction: Windows Management Instrumentation

Write a Free Memory object that uses WMI.

• Create a new text object.
• Create a new script.
• Declare a global variable like this:

Dim objWMIService

• This variable will hold the WMI provider. We initialize it on Object_OnScriptEnter and delete it on Object_OnScriptEnter. Since we are making an object that polls through WMI useful information, we will have the WMI service object always available for the object lifetime. You can find more information on MSDN about the actual syntax to create an instance. GetObject("winmgmts:\\.\root\cimv2") just means you are creating a WMI instance to query information in the cimv2 category for the local machine (\.\).

Sub Object_OnScriptEnter
Set objWMIService = GetObject("winmgmts:\\.\root\cimv2")
object.settimer 123, 5000
Object_OnTimer123 'let's update it immediately
End Sub

Sub Object_OnScriptExit
'Let's clean it, as a good practice
Set objWMIService = nothing
End Sub

• Now it is time to query WMI for getting some information. We are asking here for available system memory.

Sub Object_OnTimer123
Dim colItems
Set colItems = objWMIService.ExecQuery("Select AvailableMBytes from Win32_PerfFormattedData_PerfOS_Memory",,48)
For Each objItem In colItems
Object.text = "Available memory: " & objItem.AvailableMBytes & " MB"
'we just really need one result here, so we exit
Exit Sub
Next
End Sub
 

• You can simply reuse the above structure for different WMI queries. WMI is organized in classes. Each class contains properties. Basically, you should insert into the Select statement (Select AvailableMBytes) the properties you want accessing later (objItem.AvailableMBytes). You use the From statement (from Win32_PerfFormattedData_PerfOS_Memory) to select the class.
• For reference about other available information in the Win32 class read here: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmisdk/wmi/win32_classes.asp.
• For a complete reference about the other classes, just browse for the WMI Reference: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmisdk/wmi/wmi_reference.asp.
• I suggest you follow this link to get great ready to use examples and ideas: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmisdk/wmi/wmi_tasks_for_scripts_and_applications.asp
• Finally, another good resource is to import into DesktopX Builder some DesktopX 3.0 widgets that use WMI and see how they work:
  • Silica Drive Meter.exe uses WMI to query available logical disks and their used disk space. It is also good as a JavaScript scripting example.
  • Site Ping.exe uses WMI to monitor the response time from selected websites (PING). This one is coded in VBScript, so you can see how both work.