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我正在尝试使用 WmiSetBrightness 方法调整显示器的亮度（不是伽马斜坡值），但系统在运行时抛出 ManagementException 说“不支持”。我见过很多人使用这个概念并成功运行。那我的有什么问题吗？是不是因为这在 Windows 7 Ultimate 中不受支持？我在哪个工作？我的代码如下：

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1_Click
    Try
        Dim mclass As New ManagementClass("WmiMonitorBrightnessMethods")
        mclass.Scope = New ManagementScope("\\.\root\wmi")
        Dim instances As ManagementObjectCollection = mclass.GetInstances()

        For Each instance As ManagementObject In instances
            Dim brightness As Byte = 50 'In percent.
            Dim timeout As UInt64 = 1 'In seconds.
            Dim args As Object() = New Object() {brightness, timeout}
            instance.InvokeMethod("WmiSetBrightness", args) 'Only work on the first object.
            Exit For
        Next
    Catch ex As ManagementException
        MessageBox.Show(ex.Message)
    End Try
End Sub

为了测试实例是否从字面上获得，我注释了 foreach 部分并尝试通过 MessageBox 使用 instance.Count.ToString() 打印实例的计数，但仍然抛出异常。

作为替代方案，我尝试使用 DeviceIOControl 和 IOCTL_VIDEO_SET_DISPLAY_BRIGHTNESS 但没有成功。代码如下：

Public Class Form1
    Private Declare Auto Function CreateFile Lib "kernel32" _
    (ByVal lpFileName As String, ByVal dwDesiredAccess As Int32, _
     ByVal dwShareMode As Int32, ByVal lpSecurityAttributes As IntPtr, _
     ByVal dwCreationDisposition As Int32, _
     ByVal dwFlagsAndAttributes As Int32, ByVal hTemplateFile As IntPtr) As IntPtr

    Const GENERIC_READ As Int32 = &H80000000%
    Const SHARE_ALL As Int32 = &H7%
    Const OPEN_EXISTING As Int32 = &H3%

    Const IOCTL_VIDEO_SET_DISPLAY_BRIGHTNESS As Integer = &H23049C%

    Private Structure BRIGHTNESS
        Public ucDisplayPolicy As Byte
        Public ucACBrightness As Byte
        Public ucDCBrightness As Byte
    End Structure

    Private Declare Auto Function DeviceIoControl Lib "kernel32" _
     (ByVal hDevice As IntPtr, ByVal dwIoControlCode As Int32, _
     ByRef lpInBuffer As BRIGHTNESS, ByVal nInBufferSize As Int32, _
     ByVal lpOutBuffer As IntPtr, ByVal nOutBufferSize As Int32, _
     ByRef lpBytesReturned As Int32, ByVal lpOverlapped As IntPtr) As Boolean

    Private Declare Auto Function CloseHandle Lib "kernel32" _
     (ByVal hObject As IntPtr) As Boolean

    ''' <summary>
    ''' Set the brightness of the screen.
    ''' </summary>
    ''' <param name="Brightness">The Screen Brightness.</param>
    Private Sub SetBrightness(ByRef Brightness As BRIGHTNESS)
        ' Get the display.
        Dim pDisplay As IntPtr = _
         CreateFile("\\.\LCD", GENERIC_READ, SHARE_ALL, IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero)

        ' Set the brightness.
        DeviceIoControl(pDisplay, IOCTL_VIDEO_SET_DISPLAY_BRIGHTNESS, _
        Brightness, Runtime.InteropServices.Marshal.SizeOf(Brightness), IntPtr.Zero, 0, Nothing, IntPtr.Zero)

        ' Close the handle.
        CloseHandle(pDisplay)
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim brightness As BRIGHTNESS

        ' The brightness on DC Power.
        brightness.ucDCBrightness = 100
        ' The Brightness on AC Power.
        brightness.ucACBrightness = 100

        ' Call the function.
        SetBrightness(brightness)
    End Sub
End Class

由于某种原因，DeviceIoControl 总是返回 False。请协助整理这些。

顺便说一句，这不是关于使用 SetDeviceGammaRamp 修改伽马斜坡值，因为它会调整显示器的对比度；不是亮度。所以，关于这个问题的任何帖子都不会有太大帮助。

问候！

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1 回答 1

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对于 using WmiMonitorBrightnessMethods，args 的顺序不正确。应该是这样的：

Dim args As Object() = New Object() {timeout, brightness}

这个对我有用。

于 2016-03-28T14:51:36.277 回答