停止屏保和休眠暂时在VB.Net

Question

我无法通过屏幕保护或积极省电模式被中断很长时间运行的同步化的任务。我想打一个API调用停止省电模式，然后一旦任务完成后恢复。

下面的代码是从各个岗位peaced在一起，但对XP的电源管理设置没有影响。我究竟做错了什么？ TIA！

Private Declare Function SetThreadExecutionState Lib "kernel32" (ByVal esFlags As Long) As Long

Public Enum EXECUTION_STATE As Integer

    ES_CONTINUOUS = &H80000000
    ES_DISPLAY_REQUIRED = &H2
    ES_SYSTEM_REQUIRED = &H1
    ES_AWAYMODE_REQUIRED = &H40

End Enum

Public Shared Sub PowerSaveOff()
    SetThreadExecutionState(EXECUTION_STATE.ES_DISPLAY_REQUIRED Or EXECUTION_STATE.ES_CONTINUOUS)
End Sub

Public Shared Sub PowerSaveOn()
    SetThreadExecutionState(EXECUTION_STATE.ES_CONTINUOUS)
End Sub

下面是系统的屏幕保护程序和功率模式设置： 替代文字http://img87.imageshack.us/img87/1600/25251376.jpg 替代文字http://img403.imageshack.us/img403/8145/73347627.jpg

Answer 1

我添加EXECUTION_STATE.ES_SYSTEM_REQUIRED，其中“强制系统复位系统空闲定时器，以在工作状态”，并防止系统进入功率节省状态。我也改变了API调用约定使用EXECUTION_STATE，包裹在一个简单的工具类的一些文档的一切。

''' <summary>
''' Simple power manager class that enables applications to inform the system
''' that it is in use, thereby preventing the system from entering the sleeping
''' power state or turning off the display while the application is running.
''' </summary>
Public Class PowerManager

#Region " Private Sub New "
    Private Sub New()
        'keep compiler from creating default constructor to create utility class
    End Sub
#End Region

    ''' <summary>
    ''' Enables applications to inform the system that it is in use, thereby preventing the system from entering the sleeping power state or turning off the display while the application is running.
    ''' </summary>
    ''' <param name="esFlags">The thread's execution requirements. This parameter can be one or more of the EXECUTION_STATE values.</param>
    ''' <returns>
    ''' <para>If the function succeeds, the return value is the previous thread execution state, as a EXECUTION_STATE value.</para>
    ''' <para>If the function fails, the return value is NULL.</para>
    '''</returns>
    ''' <remarks>
    ''' <para>This function does not stop the screen saver from executing.</para>
    ''' <para>http://msdn.microsoft.com/en-us/library/aa373208.aspx</para>
    ''' </remarks>
    Private Declare Function SetThreadExecutionState Lib "kernel32" (ByVal esFlags As EXECUTION_STATE) As EXECUTION_STATE

    Public Enum EXECUTION_STATE As Integer

        ''' <summary>
        ''' Informs the system that the state being set should remain in effect until the next call that uses ES_CONTINUOUS and one of the other state flags is cleared.
        ''' </summary>
        ES_CONTINUOUS = &H80000000

        ''' <summary>
        ''' Forces the display to be on by resetting the display idle timer.
        ''' </summary>
        ES_DISPLAY_REQUIRED = &H2

        ''' <summary>
        ''' Forces the system to be in the working state by resetting the system idle timer.
        ''' </summary>
        ES_SYSTEM_REQUIRED = &H1

    End Enum

    Public Shared Function PowerSaveOff() As EXECUTION_STATE
        Return SetThreadExecutionState(EXECUTION_STATE.ES_SYSTEM_REQUIRED Or EXECUTION_STATE.ES_DISPLAY_REQUIRED Or EXECUTION_STATE.ES_CONTINUOUS)
    End Function

    Public Shared Function PowerSaveOn() As EXECUTION_STATE
        Return SetThreadExecutionState(EXECUTION_STATE.ES_CONTINUOUS)
    End Function

End Class

Public Class Form1

    Private _cancel As Boolean

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

        'set system standby to one minute

        _cancel = False

        PowerManager.PowerSaveOff()

        Do Until _cancel
            My.Application.DoEvents()
        Loop

        PowerManager.PowerSaveOn()

        'do not forget to restore your power settings

    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        _cancel = True
    End Sub

End Class

Answer 2

这对我的作品：

Private Const SPI_SETSCREENSAVEACTIVE = 17
Private Const SPI_SETSCREENSAVETIMEOUT = 15
Private Const SPIF_SENDWININICHANGE = &H2
Private Const SPIF_UPDATEINIFILE = &H1
Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Long, ByVal uParam As Long, ByVal lpvParam As Long, ByVal fuWinIni As Long) As Long

Private Sub Form_Load()
Call SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, 0, 0, SPIF_UPDATEINIFILE + SPIF_SENDWININICHANGE)
End Sub

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
Call SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, 1, 0, SPIF_UPDATEINIFILE + SPIF_SENDWININICHANGE)
End Sub

Answer 3

Microsoft.Win32.RegistryKey rkScreenSaver =
        Microsoft.Win32.Registry.CurrentUser.OpenSubKey(@" Control Panel\Desktop", true );
if ( (string)rkScreenSaver.GetValue( "ScreenSaveActive" ) == "1" )
{
   rkScreenSaver.SetValue( "ScreenSaveActive", "0" );
   rkScreenSaver.Close( );
}

这应该为你工作。

可替换地为什么不为屏幕保护程序的时间延长到10分钟