Windows API Guide: DeleteDC Function


Declare Function EnumDisplaySettings Lib "user32.dll" Alias "EnumDisplaySettingsA" (ByVal lpszDeviceName As String, ByVal iModeNum As Long, lpDevMode As DEVMODE) As Long

Platforms

  • Windows 95: Supported.
  • Windows 98: Supported.
  • Windows NT: Requires Windows NT 3.51 or later.
  • Windows 2000: Supported.
  • Windows CE: Not Supported.

Description & Usage

EnumDisplaySettings gets the display settings of one of a display device's graphics modes. Specifically, the function gets the display mode's resolution, color depth, and frequency, along with some additional information.

Return Value

If successful, the function returns a non-zero value. If an error occured, the function returns zero (Windows NT/2000: use GetLastError to get the error code).

Visual Basic-Specific Issues

None.

Parameters

lpszDeviceName
Windows 95, 98: This must be a null string. Windows NT, 2000: If this is a null string, the current display device is used. Otherwise, this is the device name of the display device to examine. The string is of the form "\\.\DisplayX", where X is 1, 2, or 3.
iModeNum
The number of the graphics mode to retrieve information about. This could also be one of the following flags specifying a graphics mode:
ENUM_CURRENT_SETTINGS
Get information about the current display settings.
ENUM_REGISTRY_SETTINGS
Get information about the display settings stored in the registry.
lpDevMode
Receives information about the graphics mode. Only the dmBitsPerPixel, dmPelsWidth, dmPelsHeight, dmDisplayFlags, and dmDisplayFrequency members have useful data in them. Before calling the function, this structure's dmSize member must be properly set.

Constant Definitions

Const ENUM_CURRENT_SETTINGS = -1 Const ENUM_REGISTRY_SETTINGS = -2

Example

Display information about the current display settings for the monitor. To use this example, place a command button named Command1 on a form window.

' This code is licensed according to the terms and conditions listed here. ' Declarations and such needed for the example: ' (Copy them to the (declarations) section of a module.) Public Type DEVMODE dmDeviceName As String * 32 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 * 32 dmUnusedPadding As Integer dmBitsPerPixel As Integer dmPelsWidth As Long dmPelsHeight As Long dmDisplayFlags As Long dmDisplayFrequency As Long ' The following only appear in Windows 95, 98, 2000 dmICMMethod As Long dmICMIntent As Long dmMediaType As Long dmDitherType As Long dmReserved1 As Long dmReserved2 As Long ' The following only appear in Windows 2000 dmPanningWidth As Long dmPanningHeight As Long End Type Public Declare Function EnumDisplaySettings Lib "user32.dll" Alias "EnumDisplaySettingsA" (ByVal lpszDeviceName As String, _ ByVal iModeNum As Long, lpDevMode As DEVMODE) As Long Public Const ENUM_CURRENT_SETTINGS = -1 Public Const ENUM_REGISTRY_SETTINGS = -2 ' *** Place the following code inside the form window. *** Private Sub Command1_Click() Dim dm As DEVMODE   ' info about the display device Dim retval As Long  ' return value ' Initialize the structure. dm.dmSize = Len(dm) ' Get the display settings for the current monitor and mode. retval = EnumDisplaySettings(vbNullString, ENUM_CURRENT_SETTINGS, dm) ' Print some information about the display. Debug.Print "- Bits Per Pixel: "; dm.dmBitsPerPixel Debug.Print "- Width (Pixels): "; dm.dmPelsWidth Debug.Print "- Height (Pixels):"; dm.dmPelsHeight Debug.Print "- Display Freq.:  "; dm.dmDisplayFrequency End Sub

See Also

ChangeDisplaySettings

Category

Devices

Back to the Function list.
Back to the Reference section.


Last Modified: January 21, 2001
This page is copyright © 2001 Paul Kuliniewicz. Copyright Information Revised October 29, 2000
Go back to the Windows API Guide home page.
E-mail: vbapi@vbapi.com Send Encrypted E-Mail
This page is at http://www.vbapi.com/ref/e/enumdisplaysettings.html



Windows API Guide
Windows API Guide - Reference - Volume 1: Version 3.0 For the MS-DOS and PC-DOS Operating Systems
ISBN: B001V0KQIY
EAN: N/A
Year: 1998
Pages: 610

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net