ManagementClass vs ManagementObjectSearcher

Question

Hello,

Using MySearcher As New ManagementClass("Win32_Diskdrive")
   For Each MyDisk As ManagementObject In MySearcher.GetInstances()

vs

Using MySearcher As New ManagementObjectSearcher(New SelectQuery("Win32_DiskDrive"))
   For Each MyDisk As ManagementObject In MySearcher.Get()

Both will work on my system, just wanted to be aware if there's one version preferred over the other one? or any cons/differences? :)

Answer 1

Hi @Peter Volz ,

The impact of using ManagementClass and ManagementObjectSearcher lies in their functionalities in Windows Management Instrumentation (WMI):

Functionality:

• ManagementClass: Primarily used for operations on WMI classes themselves, such as creating class instances, getting static class information, etc. It is used for class-level operations rather than instance-level operations.
• ManagementObjectSearcher: Primarily used for executing WMI queries and obtaining a collection of instances that match the query. It is used for instance-level operations and allows for fetching instances based on specific conditions.

Querying Method:

• ManagementClass does not provide a direct querying method. You can use the GetInstances() method to obtain all instances of a class, but it does not support complex query conditions for filtering results.
• ManagementObjectSearcher supports the use of SelectQuery objects to specify query conditions, enabling you to filter instance collections based on conditions and perform more flexible queries.

Performance:

• ManagementClass is generally more efficient when it comes to creating and obtaining class instances because it directly deals with class metadata and does not involve complex querying operations.
• ManagementObjectSearcher executes complex queries that may involve traversing a large number of instances and matching query conditions, which could result in relatively slower performance.

Use Cases:

• ManagementClass is commonly used for managing WMI classes, creating new instances, registering new classes, etc. For example, it might be used to create new WMI classes or instances on a remote computer.
• ManagementObjectSearcher is mainly used for obtaining instance information, such as retrieving hardware information, service information, process information, etc.

If your purpose is to retrieve disk drive information on the computer, which involves instance-level operations. Therefore, using ManagementObjectSearcher is more suitable as it provides more flexibility in querying and obtaining instance-level information.

Best Regards.

Jiachen Li

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