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VB.Net调用WMI可以实现系统管理和系统信息查询等。WMI全称为Windows Management Instrumentation，利用WMI我们可以实现很多系统管理的功能，msdn在.Net Framework类库中对此描述比较简单（因为早期WMI相关专题有所较详尽描述，故类库中未再详细解说与演示） 乐博网将发布一系列相关文章及实例分析帮助大家更深刻了解它。

开发环境： VB2005  Windows2003

本实例需要在菜单栏中的“项目”-“ 添加引用” -“ System.Management”

并在实例代码中导入引用的项目和程序集中定义的命名空间或编程元素 即： Imports System.Management  

VB.Net查询显示器属性信息的实例

代码如下：

 Private Sub Lobdotcn()

        Dim Lob_Searcher As New ManagementObjectSearcher("root\CIMV2", "SELECT * FROM Win32_DesktopMonitor")
        For Each Obj_Query As ManagementObject In Lob_Searcher.Get()
            ListBox1.Items.Add("乐博网LOB.Cn   VB.Net爱好者的组织")
            ListBox1.Items.Add("Availability: " & Obj_Query("Availability"))
            ListBox1.Items.Add("Bandwidth: " & Obj_Query("Bandwidth"))
            ListBox1.Items.Add("Caption: " & Obj_Query("Caption"))
            ListBox1.Items.Add("ConfigManagerErrorCode: " & Obj_Query("ConfigManagerErrorCode"))
            ListBox1.Items.Add("ConfigManagerUserConfig: " & Obj_Query("ConfigManagerUserConfig"))
            ListBox1.Items.Add("CreationClassName: " & Obj_Query("CreationClassName"))
            ListBox1.Items.Add("Description: " & Obj_Query("Description"))
            ListBox1.Items.Add("DeviceID: " & Obj_Query("DeviceID"))
            ListBox1.Items.Add("DisplayType: " & Obj_Query("DisplayType"))
            ListBox1.Items.Add("ErrorCleared: " & Obj_Query("ErrorCleared"))
            ListBox1.Items.Add("ErrorDescription: " & Obj_Query("ErrorDescription"))
            ListBox1.Items.Add("InstallDate: " & Obj_Query("InstallDate"))
            ListBox1.Items.Add("IsLocked: " & Obj_Query("IsLocked"))
            ListBox1.Items.Add("LastErrorCode: " & Obj_Query("LastErrorCode"))
            ListBox1.Items.Add("MonitorManufacturer: " & Obj_Query("MonitorManufacturer"))
            ListBox1.Items.Add("MonitorType: " & Obj_Query("MonitorType"))
            ListBox1.Items.Add("Name: " & Obj_Query("Name"))
            ListBox1.Items.Add("PixelsPerXLogicalInch: " & Obj_Query("PixelsPerXLogicalInch"))
            ListBox1.Items.Add("PixelsPerYLogicalInch: " & Obj_Query("PixelsPerYLogicalInch"))
            ListBox1.Items.Add("PNPDeviceID: " & Obj_Query("PNPDeviceID"))
            If Obj_Query("PowerManagementCapabilities") IsNot Nothing Then
                Dim arrPowerManagementCapabilities As UInt16()
                arrPowerManagementCapabilities = Obj_Query("Capabilities")
                For Each arrValue As UInt16 In arrPowerManagementCapabilities
                    ListBox1.Items.Add("arrPowerManagementCapabilities(): " & arrValue)
                Next
            End If
            ListBox1.Items.Add("PowerManagementSupported: " & Obj_Query("PowerManagementSupported"))
            ListBox1.Items.Add("ScreenHeight: " & Obj_Query("ScreenHeight"))
            ListBox1.Items.Add("ScreenWidth: " & Obj_Query("ScreenWidth"))
            ListBox1.Items.Add("Status: " & Obj_Query("Status"))
            ListBox1.Items.Add("StatusInfo: " & Obj_Query("StatusInfo"))
            ListBox1.Items.Add("SystemCreationClassName: " & Obj_Query("SystemCreationClassName"))
            ListBox1.Items.Add("SystemName: " & Obj_Query("SystemName"))
        Next

    End Sub

属性的说明：

 uint16 Availability;
  uint32 Bandwidth;
  string Caption;
  uint32 ConfigManagerErrorCode;
  boolean ConfigManagerUserConfig;
  string CreationClassName;
  string Description;
  string DeviceID;
  uint16 DisplayType;
  boolean ErrorCleared;
  string ErrorDescription;
  datetime InstallDate;
  boolean IsLocked;
  uint32 LastErrorCode;
  string MonitorManufacturer;
  string MonitorType;
  string Name;
  uint32 PixelsPerXLogicalInch;
  uint32 PixelsPerYLogicalInch;
  string PNPDeviceID;
  uint16 PowerManagementCapabilities[];
  boolean PowerManagementSupported;
  uint32 ScreenHeight;
  uint32 ScreenWidth;
  string Status;
  uint16 StatusInfo;
  string SystemCreationClassName;
  string SystemName;

Availability

Data type: uint16
Access type: Read-only

Availability and status of the device. Inherited from CIM_LogicalDevice.

Value	Meaning
1 0x1	Other
2 0x2	Unknown
3 0x3	Running or Full Power
4 0x4	Warning
5 0x5	In Test
6 0x6	Not Applicable
7 0x7	Power Off
8 0x8	Off Line
9 0x9	Off Duty
10 0xA	Degraded
11 0xB	Not Installed
12 0xC	Install Error
13 0xD	Power Save - Unknown The device is known to be in a power save mode, but its exact status is unknown.
14 0xE	Power Save - Low Power Mode The device is in a power save state but still functioning, and may exhibit degraded performance.
15 0xF	Power Save - Standby The device is not functioning, but could be brought to full power quickly.
16 0x10	Power Cycle
17 0x11	Power Save - Warning The device is in a warning state, though also in a power save mode.

Bandwidth

Data type: uint32
Access type: Read-only

Monitor's bandwidth in megahertz. If unknown, enter 0 (zero). This property is inherited from CIM_DesktopMonitor.

Caption

Data type: string
Access type: Read-only

Short description (one-line string) of the object. This property is inherited from CIM_ManagedSystemElement.

ConfigManagerErrorCode

Data type: uint32
Access type: Read-only

Win32 Configuration Manager error code.

Value	Meaning
0 0x0	Device is working properly.
1 0x1	Device is not configured correctly.
2 0x2	Windows cannot load the driver for this device.
3 0x3	Driver for this device might be corrupted, or the system may be low on memory or other resources.
4 0x4	Device is not working properly. One of its drivers or the registry might be corrupted.
5 0x5	Driver for the device requires a resource that Windows cannot manage.
6 0x6	Boot configuration for the device conflicts with other devices.
7 0x7	Cannot filter.
8 0x8	Driver loader for the device is missing.
9 0x9	Device is not working properly. The controlling firmware is incorrectly reporting the resources for the device.
10 0xA	Device cannot start.
11 0xB	Device failed.
12 0xC	Device cannot find enough free resources to use.
13 0xD	Windows cannot verify the device's resources.
14 0xE	Device cannot work properly until the computer is restarted.
15 0xF	Device is not working properly due to a possible re-enumeration problem.
16 0x10	Windows cannot identify all of the resources that the device uses.
17 0x11	Device is requesting an unknown resource type.
18 0x12	Device drivers must be reinstalled.
19 0x13	Failure using the VxD loader.
20 0x14	Registry might be corrupted.
21 0x15	System failure. If changing the device driver is ineffective, see the hardware documentation. Windows is removing the device.
22 0x16	Device is disabled.
23 0x17	System failure. If changing the device driver is ineffective, see the hardware documentation.
24 0x18	Device is not present, not working properly, or does not have all of its drivers installed.
25 0x19	Windows is still setting up the device.
26 0x1A	Windows is still setting up the device.
27 0x1B	Device does not have valid log configuration.
28 0x1C	Device drivers are not installed.
29 0x1D	Device is disabled. The device firmware did not provide the required resources.
30 0x1E	Device is using an IRQ resource that another device is using.
31 0x1F	Device is not working properly. Windows cannot load the required device drivers.

ConfigManagerUserConfig

Data type: boolean
Access type: Read-only

If TRUE, the device is using a user-defined configuration. This property is inherited from CIM_LogicalDevice.

CreationClassName

Data type: string
Access type: Read-only
Qualifiers: Key, MaxLen(256)

Name of the first concrete class to appear in the inheritance chain used in the creation of an instance. When used with the other key properties of the class, the property allows all instances of this class and its subclasses to be uniquely identified. This property is inherited from CIM_LogicalDevice.

Description

Data type: string
Access type: Read-only

Description of the object. This property is inherited from CIM_ManagedSystemElement.

DeviceID

Data type: string
Access type: Read-only

Unique identifier of a desktop monitor. This property is inherited from CIM_LogicalDevice.

DisplayType

Data type: uint16
Access type: Read-only

Type of desktop monitor or CRT. This property is inherited from CIM_DesktopMonitor.

Value	Meaning
0	Unknown
1	Other
2	Multiscan Color
3	Multiscan Monochrome
4	Fixed Frequency Color
5	Fixed Frequency Monochrome

ErrorCleared

Data type: boolean
Access type: Read-only

If TRUE, the error reported in LastErrorCode is now cleared. This property is inherited from CIM_LogicalDevice.

ErrorDescription

Data type: string
Access type: Read-only

Free-form string supplying more information about the error recorded in LastErrorCode, and information on any corrective actions that may be taken. This property is inherited from CIM_LogicalDevice.

InstallDate

Data type: datetime
Access type: Read-only

Date and time the object was installed. This property does not need a value to indicate that the object is installed. This property is inherited from CIM_ManagedSystemElement.

IsLocked

Data type: boolean
Access type: Read-only

If TRUE, the device is locked, preventing user input or output. This property is inherited from CIM_UserDevice.

LastErrorCode

Data type: uint32
Access type: Read-only

Last error code reported by the logical device. This property is inherited from CIM_LogicalDevice.

MonitorManufacturer

Data type: string
Access type: Read-only

Name of the monitor manufacturer.

Example: "NEC"

MonitorType

Data type: string
Access type: Read-only

Type of monitor.

Example: "NEC 5FGp"

Name

Data type: string
Access type: Read-only

Label by which the object is known. When subclassed, the property can be overridden to be a key property. This property is inherited from CIM_ManagedSystemElement.

PixelsPerXLogicalInch

Data type: uint32
Access type: Read-only
Qualifiers: Units(Pixels per Logical Inch)

Resolution along the X axis (horizontal direction) of the monitor.

PixelsPerYLogicalInch

Data type: uint32
Access type: Read-only
Qualifiers: Units(Pixels per Logical Inch)

Resolution along the Y axis (vertical direction) of the monitor.

PNPDeviceID

Data type: string
Access type: Read-only

Windows Plug and Play device identifier of the logical device. This property is inherited from CIM_LogicalDevice.

Example: "*PNP030b"

PowerManagementCapabilities

Data type: uint16 array
Access type: Read-only

Array of the specific power-related capabilities of a logical device. This property is inherited from CIM_LogicalDevice.

Value	Meaning
0 0x0	Unknown
1 0x1	Not Supported
2 0x2	Disabled
3 0x3	Enabled The power management features are currently enabled but the exact feature set is unknown or the information is unavailable.
4 0x4	Power Saving Modes Entered Automatically The device can change its power state based on usage or other criteria.
5 0x5	Power State Settable The SetPowerState method is supported. This method is found on the parent CIM_LogicalDevice class and can be implemented. For more information, see Designing Managed Object Format (MOF) Classes.
6 0x6	Power Cycling Supported The SetPowerState method can be invoked with the PowerState parameter set to 5 (Power Cycle).
7 0x7	Timed Power-On Supported The SetPowerState method can be invoked with the PowerState parameter set to 5 (Power Cycle) and Time set to a specific date and time, or interval, for power-on.

PowerManagementSupported

Data type: boolean
Access type: Read-only

If TRUE, the device can be power-managed (can be put into suspend mode, and so on). The property does not indicate that power management features are currently enabled, only that the logical device is capable of power management. This property is inherited from CIM_LogicalDevice.

ScreenHeight

Data type: uint32
Access type: Read-only

Logical height of the display in screen coordinates. This property is inherited from CIM_DesktopMonitor.

ScreenWidth

Data type: uint32
Access type: Read-only

Logical width of the display in screen coordinates. This property is inherited from CIM_DesktopMonitor.

Status

Data type: string
Access type: Read-only

Current status of the object. Various operational and nonoperational statuses can be defined. Operational statuses include: "OK", "Degraded", and "Pred Fail" (an element, such as a SMART-enabled hard disk drive, may be functioning properly but predicting a failure in the near future). Nonoperational statuses include: "Error", "Starting", "Stopping", and "Service". The latter, "Service", could apply during mirror-resilvering of a disk, reload of a user permissions list, or other administrative work. Not all such work is online, yet the managed element is neither "OK" nor in one of the other states. This property is inherited from CIM_ManagedSystemElement.

The values are:

"OK"

"Error"

"Degraded"

"Unknown"

"Pred Fail"

"Starting"

"Stopping"

"Service"

StatusInfo

Data type: uint16
Access type: Read-only

State of the logical device. If this property does not apply to the logical device, the value 5 (Not Applicable) should be used. This property is inherited from CIM_LogicalDevice.

Value	Meaning
1 0x1	Other
2 0x2	Unknown
3 0x3	Enabled
4 0x4	Disabled
5 0x5	Not Applicable

SystemCreationClassName

Data type: string
Access type: Read-only

Value of the scoping computer's CreationClassName property. This property is inherited from CIM_LogicalDevice.

SystemName

Data type: string
Access type: Read-only

Name of the scoping system. This property is inherited from CIM_LogicalDevice.