54.txt

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如何动态改变屏幕设置？
 

　　我们经常看到许多 Win95 的应用程序（尤其是游戏）在运行它的时候改变屏幕的设置，运行完后恢复，在 VB 中，我们可以用以下方法实现：
　
定义
Private Declare Function lstrcpy Lib "kernel32" Alias _
　 "lstrcpyA" (lpString1 As Any, lpString2 As Any) As Long

Const CCHDEVICENAME = 32
Const CCHFORMNAME = 32

Private Type DEVMODE
　 dmDeviceName As String * CCHDEVICENAME
　 dmSpecVersion As Integer
　 dmDriverVersion As Integer
　 dmSize As Integer
　 dmDriverExtra As Integer
　 dmFields As Long
　 dmOrientation As Integer
　 dmPaperSize As Integer
　 dmPaperLength As Integer
　 dmPaperWidth As Integer
　 dmScale As Integer
　 dmCopies As Integer
　 dmDefaultSource As Integer
　 dmPrintQuality As Integer
　 dmColor As Integer
　 dmDuplex As Integer
　 dmYResolution As Integer
　 dmTTOption As Integer
　 dmCollate As Integer
　 dmFormName As String * CCHFORMNAME
　 dmUnusedPadding As Integer
　 dmBitsPerPel As Integer
　 dmPelsWidth As Long
　 dmPelsHeight As Long
　 dmDisplayFlags As Long
　 dmDisplayFrequency As Long
End Type

Private Declare Function ChangeDisplaySettings Lib "User32" _
　 Alias "ChangeDisplaySettingsA" (ByVal lpDevMode As Long, _
　 ByVal dwflags As Long) As Long
　
'函数
Public Function SetDisplayMode(Width As Integer, _
　 Height As Integer, Color As Integer) As Long
　 Const DM_PELSWIDTH = &H80000
　 Const DM_PELSHEIGHT = &H100000
　 Const DM_BITSPERPEL = &H40000
　 Dim NewDevMode As DEVMODE
　 Dim pDevmode As Long
　 With NewDevMode
　　　.dmSize = 122
　　　If Color = -1 Then
　　　　 .dmFields = DM_PELSWIDTH Or DM_PELSHEIGHT
　　　Else
　　　　 .dmFields = DM_PELSWIDTH Or DM_PELSHEIGHT Or DM_BITSPERPEL
　　　End If
　　　.dmPelsWidth = Width
　　　.dmPelsHeight = Height
　　　If Color <> -1 Then
　　　　 .dmBitsPerPel = Color
　　　End If
　 End With
　 pDevmode = lstrcpy(NewDevMode, NewDevMode)
　 SetDisplayMode = ChangeDisplaySettings(pDevmode, 0)
End Function
　
例子调用：改变为 640x480x24位：
i = SetDisplayMode(640, 480, 24)
如果成功返回 0 。