微软.net精简框架常见问题及回答(中文版)(22)
Verify that the DLL being imported is not dependant upon other DLLs. A missing dependant DLL will result in the MissingMethodException. For the latest Microsoft eMbedded Visual Tools and SDK downloads, visit the MSDN Mobile and Embedded Developer Center "Products & Updates" download page at:
http://msdn.microsoft.com/mobility/downloads/updates/default.aspx
6.16. How do I set the system time?
You can set the system time by P/Invoking the SetSystemTime function. //C#
using System.Runtime.InteropServices;
public struct SYSTEMTIME
{
public ushort wYear;
public ushort wMonth;
public ushort wDayOfWeek;
public ushort wDay;
public ushort wHour;
public ushort wMinute;
public ushort wSecond;
public ushort wMilliseconds;
}
[DllImport("coredll.dll")]
public extern static void GetSystemTime(ref SYSTEMTIME lpSystemTime);
[DllImport("coredll.dll")]
public extern static uint SetSystemTime(ref SYSTEMTIME lpSystemTime);
// Set the clock ahead one hour
SYSTEMTIME st = new SYSTEMTIME();
GetSystemTime(ref st);
st.wHour = (ushort)(st.wHour + 1 % 24);
SetSystemTime(ref st);
'VB
Imports System.Runtime.InteropServices
Public Structure SYSTEMTIME
Public wYear As UInt16
Public wMonth As UInt16
Public wDayOfWeek As UInt16
Public wDay As UInt16
Public wHour As UInt16
Public wMinute As UInt16
Public wSecond As UInt16
Public wMilliseconds As UInt16
End Structure
<DllImport("coredll.dll")> _
Public Shared Sub GetSystemTime(ByRef lpSystemTime As SYSTEMTIME)
End Sub
<DllImport("coredll.dll")> _
Public Shared Function SetSystemTime(ByRef lpSystemTime As SYSTEMTIME) As UInt32
End Function
'Set the clock ahead one hour
Dim st As New SYSTEMTIME
GetSystemTime(st)
st.wHour = Convert.ToUInt16(((Convert.ToInt32(st.wHour) + 1)) Mod 24)
SetSystemTime(st)
6.17. How do I programmatically soft reset the device?
The device can be soft reset through P/Invoking of the KernelIoControl function, as demonstrated in the code below. For more information on how to use the function and extend the functionality of this sample, refer to Visual Studio .NET Help.
Note: On Smartphone devices, this will only work if you are signed with a privileged certificate. //C#
using System.Runtime.InteropServices;
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
);
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);
}