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ExtEscape (coredll)

coredll is for smart devices, not desktop Windows. Therefore, this information only applies to code using the .NET Compact Framework. To see if information for ExtEscape in other DLLs exists, click on Find References to the right.

The ExtEscape function enables applications to access capabilities of a particular device that are not available through GDI.

C# Signature:

[DllImport("coredll.dll", SetLastError=true)]
static extern int ExtEscape(
        IntPtr hdc,
        uint nEscape,
        uint cbInput,
        byte[] lpszInData,
        int cbOutput,
        IntPtr lpszOutData


VB Signature:

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

User-Defined Types:

public class DefinedConsts


    // GDI Escapes for ExtEscape()
    private const uint QUERYESCSUPPORT   = 8;

    // The following are unique to CE
    private const uint GETVFRAMEPHYSICAL =  6144;
    private const uint GETVFRAMELEN   = 6145;
    private const uint DBGDRIVERSTAT   = 6146;
    private const uint SETPOWERMANAGEMENT =  6147;
    private const uint GETPOWERMANAGEMENT =  6148;


public enum VideoPowerState : uint


    VideoPowerOn = 1,



Turn Off the Display While Running Applications

Applications like the Microsoft® Windows Media™ Player for Pocket PC allow the user to turn off the display while the application is running in the background. This article shows you how to do this with your own applications.

Applies to:

Microsoft® Windows® Powered Pocket PC 2000

Microsoft eMbedded Visual Tools

Microsoft eMbedded Visual C++®

Languages Supported

All languages.

Tips & Tricks:

Please add some!

Sample Code:

public class CFVideo


    public static void PowerOff()
        IntPtr hdc = GetDC(IntPtr.Zero);
        uint func = SETPOWERMANAGEMENT;

        uint size = 12;
        byte[] vpm = new byte[size];

        //structure size
        BitConverter.GetBytes(size).CopyTo(vpm, 0);
        //dpms version
        BitConverter.GetBytes(0x0001).CopyTo(vpm, 4);
        //power state
        BitConverter.GetBytes((uint)VideoPowerState.VideoPowerOff).CopyTo(vpm, 8);

        ExtEscapeSet(hdc, SETPOWERMANAGEMENT, size, vpm, 0, IntPtr.Zero);

    [DllImport("coredll", EntryPoint="ExtEscape")]
    private static extern int ExtEscapeSet(
        IntPtr hdc,
        uint nEscape,
        uint cbInput,
        byte[] lpszInData,
        int cbOutput,
        IntPtr lpszOutData

    private static extern IntPtr GetDC(IntPtr hwnd);


Alternative Managed API:

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ExtEscape on MSDN

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