How can I cycle a USB device from C#?

问题:

I'd like to cycle (simulate unplug and re-inserting) a USB device (modem) after a certain event has fired. I found a sample on codeproject:

http://www.codeproject.com/KB/system/usbeject.aspx

That allows me to identify+eject the device via its non-volatile serial, but I need it to recycle, not just eject.

I have read this:

http://www.tech-archive.net/Archive/Development/microsoft.public.development.device.drivers/2005-02/1292.html

I do not understand it.

This has been mentioned in other USB related posts:

http://www.codeproject.com/KB/system/DriveDetector.aspx

It is not relevant to my problem.

回答1:

Got it working by using a commandline tool called devcon, which I then called from code.

Dropped devcon.exe into one of the system paths so it works everywhere.

Devcon: devcon

called: DEVCON Remove *usb"*MI_01"

then called: DEVCON rescan

code:

 System.Diagnostics.Process proc = new System.Diagnostics.Process();
 proc.StartInfo.FileName = "DEVCON";
 proc.StartInfo.Arguments = "Remove *usb"*MI_01";
 proc.StartInfo.RedirectStandardError = true;
 proc.StartInfo.RedirectStandardOutput = true;
 proc.StartInfo.UseShellExecute = false;
 proc.Start();

回答2:

You can use the C# Hardware Helper Lib and add the ResetDevice function.

Just make sure you add

public const int DICS_PROPCHANGE = ((0x00000003)); 

at the public class Native under //PARMS,

public bool ResetDevice( IntPtr hDevInfo, IntPtr devInfoData )
{
int szOfPcp;
IntPtr ptrToPcp;
int szDevInfoData;
IntPtr ptrToDevInfoData;

Native.SP_PROPCHANGE_PARAMS pcp = new Native.SP_PROPCHANGE_PARAMS();
pcp.ClassInstallHeader.cbSize = Marshal.SizeOf(typeof(Native.SP_CLASSINSTALL_HEADER));
pcp.ClassInstallHeader.InstallFunction = Native.DIF_PROPERTYCHANGE;
pcp.StateChange = Native.DICS_PROPCHANGE; // for reset
pcp.Scope = Native.DICS_FLAG_CONFIGSPECIFIC;
pcp.HwProfile = 0;

szOfPcp = Marshal.SizeOf(pcp);
ptrToPcp = Marshal.AllocHGlobal(szOfPcp);
Marshal.StructureToPtr(pcp, ptrToPcp, true);
szDevInfoData = Marshal.SizeOf(devInfoData);
ptrToDevInfoData = Marshal.AllocHGlobal(szDevInfoData);
Marshal.StructureToPtr(devInfoData, ptrToDevInfoData, true);

bool rslt1 = Native.SetupDiSetClassInstallParams(hDevInfo, ptrToDevInfoData, ptrToPcp, Marshal.SizeOf(typeof(Native.SP_PROPCHANGE_PARAMS)));
bool rstl2 = Native.SetupDiCallClassInstaller(Native.DIF_PROPERTYCHANGE, hDevInfo, ptrToDevInfoData);

if (rslt1 && rstl2)
{
    return true;
}
return false;
}