Easy access to system information in. NET (1)-wmi article Montaque (original)

Easy access to system information in. NET (1)-wmi article Montaque (original)

Key word Wmi,wql,managementobjectsearcher



Easy access to system information in. NET (1)-WMI article

Montaque

Statement:

1, a little personal experience, for reference only
2, reprint time, please reserve original.




Overview:

Do not know if you have this experience? Sometimes to get a little bit of information about the system, consider the version number of the operating system, or the resolution of the current screen. In fact, the bottom line is to read a certain aspect of the operating system of a property value, and then see our program in the dense WIN32 API declarations, calls, code readability and maintenance of self-evident. To. NET, Microsoft offers a richer class, and many of the methods used to invoke the API can be easily invoked in. Net. Today a brief introduction is in. NET for the purpose of obtaining information through communication with WMI (Windows Management specification).

Main ideas:

For an example of obtaining the operating system shared directory and obtaining the motherboard number, this article describes how to obtain system-related information using the classes below system.managment:



Body:

WMI (Windows Management Specification: Windows Management Instrumentation) is the implementation of Microsoft's Web-based Enterprise Management (WBEM) and is also a standards-based system management interface. WMI first appears on a Microsoft Windows 2000 system, but it can also be installed on Windows NT 4 and Windows 9x computers. WMI is a powerful tool for easy access to system information.

In. NET, there is a system.management name space (the system defaults to no reference, we can manually add a reference), through the following class operation, you can query the system software and hardware information, first look at a simple example:



Imports System.Management

Dim Searcher as New managementobjectsearcher ("SELECT * from Win32_Share")

Dim Share as ManagementObject

For each share in searcher. Get ()

MessageBox.Show (share. GetText (Textformat.mof))

Next Share


The result of the run is a list of directories that are currently shared by all systems, as well as descriptions, and so on.



Analysis of the above code, you can see a few:

1, seems to be in the database operation, a bit like SQL statements. In fact, the SQL operation, the statement is WQL (WMI Query Language), is actually a subset of standard SQL plus the extension of WMI.

2, WQL is a read-only query language, we can only query the response data, can not use Update,insert and other update operations

3, the code is very simple, easy to understand

4, we use a MOF (Managed Object format) display.



Example two: Get information on the current motherboard

The above example is a software aspect of information, look at a sample of hardware information to obtain the motherboard serial number and manufacturer:

Dim Searcher as New managementobjectsearcher ("SELECT * from Win32_baseboard")

Dim Share as ManagementObject

For each share in searcher. Get ()

Debug.WriteLine ("Motherboard manufacturer:" & Share ("Manufacturer"))

Debug.WriteLine ("Model:" & Share ("Product"))

Debug.WriteLine ("Serial number:" & Share ("SerialNumber"))

Next Share


Summary and supplement:

WMI classes are also layered, referring to WMI in MSDN; NET platform development, it is best to read more about. NET new features, which can greatly improve the development efficiency of the Code and the running efficiency. <