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How to: Reset the DeviceĀ 

To reset the device, use platform invoke to call the native KernelIoControl function.

Example

This code example defines the following:

  • Platform invoke declarations for the native functions in Windows CE.

  • A method named ResetDevice that displays a confirmation message box. If the user responds yes, the ResetPocktPC method resets the device.

Private Const FILE_DEVICE_HAL As Integer = &H101
Private Const METHOD_BUFFERED As Integer = 0
Private Const FILE_ANY_ACCESS As Integer = 0

Private Function CTL_CODE( _
  ByVal DeviceType As Integer, _
  ByVal Func As Integer, _
  ByVal Method As Integer, _
  ByVal Access As Integer) As Integer

    Return (DeviceType << 16) Or (Access << 14) Or (Func << 2) Or Method

End Function 

Declare Function KernelIoControl Lib "CoreDll.dll" _
    (ByVal dwIoControlCode As Integer, _
     ByVal lpInBuf As IntPtr, _
     ByVal nInBufSize As Integer, _
     ByVal lpOutBuf As IntPtr, _
     ByVal nOutBufSize As Integer, _
     ByRef lpBytesReturned As Integer _
    ) As Integer

Private Function ResetPocketPC() As Integer
    Dim bytesReturned As Integer = 0
    Dim IOCTL_HAL_REBOOT As Integer = CTL_CODE(FILE_DEVICE_HAL, _
      15, METHOD_BUFFERED, FILE_ANY_ACCESS)
    Return KernelIoControl(IOCTL_HAL_REBOOT, IntPtr.Zero, 0, _
      IntPtr.Zero, 0, bytesReturned)
End Function 

Private Sub ResetDevice()
    Dim msg As String
    Dim title As String
    Dim style As MsgBoxStyle
    Dim response As MsgBoxResult
    msg = "Are you sure you want to reset the device?"
    style = MsgBoxStyle.DefaultButton2 Or _
       MsgBoxStyle.Question Or MsgBoxStyle.YesNo
    title = "Device Reset"
    response = MsgBox(msg, style, title)
    If response = MsgBoxResult.Yes Then   ' User chose Yes.
       ResetPocketPC()
    End If

End Sub 
public const uint FILE_DEVICE_HAL = 0x00000101;
public const uint METHOD_BUFFERED = 0;
public const uint FILE_ANY_ACCESS = 0;

public uint CTL_CODE(uint DeviceType, uint Function, uint Method, uint Access)
{
    return ((DeviceType << 16) | (Access << 14) | (Function << 2) | Method);
}

[DllImport("Coredll.dll")]
public extern static uint KernelIoControl
(
    uint dwIoControlCode,
    IntPtr lpInBuf,
    uint nInBufSize,
    IntPtr lpOutBuf,
    uint nOutBufSize,
    ref uint lpBytesReturned
);

private uint ResetPocketPC()
{
    uint bytesReturned = 0;
    uint IOCTL_HAL_REBOOT = CTL_CODE(FILE_DEVICE_HAL, 15, 
      METHOD_BUFFERED, FILE_ANY_ACCESS);
    return KernelIoControl(IOCTL_HAL_REBOOT, IntPtr.Zero, 0, 
      IntPtr.Zero, 0, ref bytesReturned);
}

private void ResetDevice()
{
    DialogResult r = MessageBox.Show
    (
        "Are you sure you want to reset?",
        "Test",
        MessageBoxButtons.YesNo,
        MessageBoxIcon.Question,
        MessageBoxDefaultButton.Button2
    );

    if (r == DialogResult.Yes)
    {
        ResetPocketPC();
    }
}

Compiling the Code

This example requires references to the following namespaces:

See Also

Other Resources

Interoperability in the .NET Compact Framework