// Find the index of the particular DeviceInfoData for the instanceId.
static int GetIndexOfInstance(NativePlugAndPlayHelper.SafeDeviceInfoSetHandle handle, NativePlugAndPlayHelper.DeviceInfoData[] diData, string instanceId)
{
const int ERROR_INSUFFICIENT_BUFFER = 122;
for (int index = 0; index <= diData.Length - 1; index++)
{
StringBuilder sb = new StringBuilder(1);
int requiredSize = 0;
bool result = NativePlugAndPlayHelper.SetupDiGetDeviceInstanceId(handle.DangerousGetHandle(), ref diData[index], sb, sb.Capacity, out requiredSize);
if (result == false && Marshal.GetLastWin32Error() == ERROR_INSUFFICIENT_BUFFER)
{
sb.Capacity = requiredSize;
result = NativePlugAndPlayHelper.SetupDiGetDeviceInstanceId(handle.DangerousGetHandle(), ref diData[index], sb, sb.Capacity, out requiredSize);
}
if (result == false)
{
throw new Win32Exception();
}
if (instanceId.Equals(sb.ToString()))
{
return(index);
}
}
// not found
return(-1);
}
/// <summary>
/// Enable or disable a device.
/// </summary>
/// <param name="classGuid">The class guid of the device. Available in the device manager.</param>
/// <param name="instanceId">The device instance id of the device. Available in the device manager.</param>
/// <param name="enable">True to enable, False to disable.</param>
/// <remarks>Will throw an exception if the device is not Disableable.</remarks>
public static void SetDeviceEnabled(Guid classGuid, string instanceId, bool enable)
{
NativePlugAndPlayHelper.SafeDeviceInfoSetHandle diSetHandle = null;
try
{
// Get the handle to a device information set for all devices matching classGuid that are present on the
// system.
diSetHandle = NativePlugAndPlayHelper.SetupDiGetClassDevs(ref classGuid, null, IntPtr.Zero, NativePlugAndPlayHelper.SetupDiGetClassDevsFlags.Present);
// Get the device information data for each matching device.
NativePlugAndPlayHelper.DeviceInfoData[] diData = GetDeviceInfoData(diSetHandle);
// Find the index of our instance. i.e. the touchpad mouse - I have 3 mice attached...
int index = GetIndexOfInstance(diSetHandle, diData, instanceId);
// Disable...
EnableDevice(diSetHandle, diData[index], enable);
}
finally
{
if (diSetHandle != null)
{
if (diSetHandle.IsClosed == false)
{
diSetHandle.Close();
}
diSetHandle.Dispose();
}
}
}
static NativePlugAndPlayHelper.DeviceInfoData[] GetDeviceInfoData(NativePlugAndPlayHelper.SafeDeviceInfoSetHandle handle)
{
List <NativePlugAndPlayHelper.DeviceInfoData> data = new List <NativePlugAndPlayHelper.DeviceInfoData>();
NativePlugAndPlayHelper.DeviceInfoData did = new NativePlugAndPlayHelper.DeviceInfoData();
int didSize = Marshal.SizeOf(did);
did.Size = didSize;
int index = 0;
while (NativePlugAndPlayHelper.SetupDiEnumDeviceInfo(handle, index, ref did))
{
data.Add(did);
index += 1;
did = new NativePlugAndPlayHelper.DeviceInfoData();
did.Size = didSize;
}
return(data.ToArray());
}
// enable/disable...
static void EnableDevice(NativePlugAndPlayHelper.SafeDeviceInfoSetHandle handle, NativePlugAndPlayHelper.DeviceInfoData diData, bool enable)
{
NativePlugAndPlayHelper.PropertyChangeParameters pars = new NativePlugAndPlayHelper.PropertyChangeParameters();
// The size is just the size of the header, but we've flattened the structure.
// The header comprises the first two fields, both integer.
pars.Size = 8;
pars.DiFunction = NativePlugAndPlayHelper.DiFunction.PropertyChange;
pars.Scope = NativePlugAndPlayHelper.Scopes.Global;
if (enable)
{
pars.StateChange = NativePlugAndPlayHelper.StateChangeAction.Enable;
}
else
{
pars.StateChange = NativePlugAndPlayHelper.StateChangeAction.Disable;
}
bool result = NativePlugAndPlayHelper.SetupDiSetClassInstallParams(handle, ref diData, ref pars, Marshal.SizeOf(pars));
if (result == false)
{
throw new Win32Exception();
}
result = NativePlugAndPlayHelper.SetupDiCallClassInstaller(NativePlugAndPlayHelper.DiFunction.PropertyChange, handle, ref diData);
if (result == false)
{
int err = Marshal.GetLastWin32Error();
if (err == (int)NativePlugAndPlayHelper.SetupApiError.NotDisableable)
{
throw new ArgumentException("Device can't be disabled (programmatically or in Device Manager).");
}
else if (err >= (int)NativePlugAndPlayHelper.SetupApiError.NoAssociatedClass && err <= (int)NativePlugAndPlayHelper.SetupApiError.OnlyValidateViaAuthenticode)
{
throw new Win32Exception("SetupAPI error: " + ((NativePlugAndPlayHelper.SetupApiError)err).ToString());
}
else
{
throw new Win32Exception();
}
}
}
