Question

我有一个很长的运行同步任务，不能被屏幕保护程序或积极的省电模式中断。我想进行一次api调用以停止省电模式，然后在任务完成后恢复它。

以下代码与其他各个帖子并列，但它对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

以下是系统屏幕保护程序和powermode设置： alt text http://img87.imageshack.us/img87/1600/25251376.jpg alt text http://img403.imageshack.us/img403/8145/73347627.jpg

Answer 1

我添加了EXECUTION_STATE.ES_SYSTEM_REQUIRED，“通过重置系统空闲计时器强制系统处于工作状态”，并阻止系统进入省电状态。我还将API调用约定更改为使用EXECUTION_STATE，将所有内容都包含在一个带有一些文档的简单实用程序类中。

''' <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

这对我有用：

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( );
}

这应该适合你。

或者为什么不将屏幕保护程序的时间延长到10分钟？

在VB.Net中暂时停止屏幕保护程序和休眠

3 个答案: