VB中利用API函数实现屏幕颜色数设定

　　原则上，只改这一次，下一次开机会还原，但如果需重开机，才会Update ReGIStry中的设定，并重开机。

　　如果要永久设定其设定值，请将

b = ChangeDisplaySettings(DevM, 0)

　　改成

b = ChangeDisplaySettings(DevM, CDS_UPDATEREGISTRY)

　　注：

　　DevM.dmBitsPERPel 便是设定颜色数，其实应说每个Pixel要多少Bits来显示

　　4 --> 16色
　　8 --> 256色
　　16 --> 65536色 以此类推

Option Explicit
Private Declare Function EnumDisplaySettings Lib "user32" Alias _
"EnumDisplaySettingsA" (ByVal lpszDeviceName As Long, _
ByVal iModeNum As Long, lpDevMode As Any) As Long

Private Declare Function ChangeDisplaySettings Lib "user32" Alias _
"ChangeDisplaySettingsA" (lpDevMode As Any, ByVal dwflags As Long) As Long
Private Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As Long, _
ByVal dwReserved As Long) As Long

Const EWX_REBOOT = 2 ’ 重开机
Const CCDEVICENAME = 32
Const CCFORMNAME = 32

Const DM_BITSPERPEL = &H40000
Const DISP_CHANGE_SUCCESSFUL = 0
Const DISP_CHANGE_RESTART = 1
Const CDS_UPDATEREGISTRY = 1
Private Type DEVMODE
dmDeviceName As String * CCDEVICENAME
dmSpecVersion As Integer
dmDriverVersion As Integer
dmSize As Integer
dmDriverExtra As Integer