If you want to conserve battery power, but dont want to switch off or suspend your device you can use this code to simply switch off the display!
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Namespace PDA Public Class Video Private Const SETPOWERMANAGEMENT As Int32 = 6147 Declare Function ExtEscapeSet Lib "coredll" Alias "ExtEscape" (ByVal hdc As IntPtr, _ ByVal nEscape As Int32, _ ByVal cbInput As Int32, _ ByVal plszInData As Byte(), _ ByVal cbOutput As Int32, _ ByVal lpszOutData As IntPtr) As Int32 Declare Function GetDC Lib "coredll" (ByVal hwnd As IntPtr) As IntPtr Public Enum VideoPowerState As Integer VideoPowerOn = 1 VideoPowerStandBy VideoPowerSuspend VideoPowerOff End Enum Public Shared Sub PowerOff() Dim hdc As IntPtr = GetDC(IntPtr.Zero) Dim vpm() As Byte = {12, 0, 0, 0, 1, 0, 0, 0, VideoPowerState.VideoPowerOff, 0, 0, 0, 0} ExtEscapeSet(hdc, SETPOWERMANAGEMENT, 12, vpm, 0, IntPtr.Zero) End Sub Public Shared Sub PowerOn() Dim hdc As IntPtr = GetDC(IntPtr.Zero) Dim vpm() As Byte = {12, 0, 0, 0, 1, 0, 0, 0, VideoPowerState.VideoPowerOn, 0, 0, 0, 0} ExtEscapeSet(hdc, SETPOWERMANAGEMENT, 12, vpm, 0, IntPtr.Zero) End Sub End Class End Namespace |