/// <summary>
/// Returns a device instance property identified by <see cref="DevicePropertyKey" />.
/// </summary>
/// <typeparam name="T">The managed type of the fetched porperty value.</typeparam>
/// <param name="propertyKey">The <see cref="DevicePropertyKey" /> to query for.</param>
/// <returns>On success, the value of the queried property.</returns>
public T GetProperty <T>(DevicePropertyKey propertyKey)
{
if (typeof(T) != propertyKey.PropertyType)
{
throw new ArgumentException(
"The supplied object type doesn't match the property type.",
nameof(propertyKey)
);
}
var buffer = IntPtr.Zero;
try
{
var ret = GetProperty(
propertyKey.ToNativeType(),
out var propertyType,
out buffer,
out var size
);
if (ret == SetupApiWrapper.ConfigManagerResult.NoSuchValue ||
propertyType == SetupApiWrapper.DevPropType.Empty)
{
return(default(T));
}
if (ret != SetupApiWrapper.ConfigManagerResult.Success)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
if (!NativeToManagedTypeMap.TryGetValue(propertyType, out var managedType))
{
throw new ArgumentException(
"Unknown property type.",
nameof(propertyKey)
);
}
if (typeof(T) != managedType)
{
throw new ArgumentException(
"The supplied object type doesn't match the property type.",
nameof(propertyKey)
);
}
#region Don't look, nasty trickery
/*
* Handle some native to managed conversions
*/
// Regular strings
if (managedType == typeof(string))
{
var value = Marshal.PtrToStringUni(buffer);
return((T)Convert.ChangeType(value, typeof(T)));
}
// Double-null-terminated string to list
if (managedType == typeof(string[]))
{
return((T)(object)Marshal.PtrToStringUni(buffer, (int)size / 2).TrimEnd('\0').Split('\0')
.ToArray());
}
// Byte & SByte
if (managedType == typeof(sbyte) ||
managedType == typeof(byte))
{
return((T)(object)Marshal.ReadByte(buffer));
}
// (U)Int16
if (managedType == typeof(short) ||
managedType == typeof(ushort))
{
return((T)(object)(ushort)Marshal.ReadInt16(buffer));
}
// (U)Int32
if (managedType == typeof(int) ||
managedType == typeof(uint))
{
return((T)Convert.ChangeType(Marshal.ReadInt32(buffer), managedType));
}
// (U)Int64
if (managedType == typeof(long) ||
managedType == typeof(ulong))
{
return((T)(object)(ulong)Marshal.ReadInt64(buffer));
}
// FILETIME/DateTimeOffset
if (managedType == typeof(DateTimeOffset))
{
return((T)(object)DateTimeOffset.FromFileTime(Marshal.ReadInt64(buffer)));
}
#endregion
throw new NotImplementedException("Type not supported.");
}
finally
{
Marshal.FreeHGlobal(buffer);
}
}
/// <summary>
/// Creates or updates an existing property with a given value.
/// </summary>
/// <typeparam name="T">The type of the property.</typeparam>
/// <param name="propertyKey">The <see cref="DevicePropertyKey"/> to update.</param>
/// <param name="propertyValue">The value to set.</param>
public void SetProperty <T>(DevicePropertyKey propertyKey, T propertyValue)
{
if (typeof(T) != propertyKey.PropertyType)
{
throw new ArgumentException(
"The supplied object type doesn't match the property type.",
nameof(propertyKey)
);
}
var managedType = typeof(T);
var nativePropKey = propertyKey.ToNativeType();
var nativePropType = NativeToManagedTypeMap.FirstOrDefault(t => t.Value == managedType).Key;
uint propBufSize = 0;
IntPtr buffer = IntPtr.Zero;
#region Don't look, nasty trickery
/*
* Handle some native to managed conversions
*/
// Regular strings
if (managedType == typeof(string))
{
var value = (string)(object)propertyValue;
buffer = Marshal.StringToHGlobalUni(value);
propBufSize = (uint)((value.Length + 1) * 2);
}
// Double-null-terminated string to list
//if (managedType == typeof(string[]))
// return (T) (object) Marshal.PtrToStringUni(buffer, (int) size / 2).TrimEnd('\0').Split('\0')
// .ToArray();
// Byte & SByte
if (managedType == typeof(sbyte) ||
managedType == typeof(byte))
{
var value = (byte)(object)propertyValue;
propBufSize = (uint)Marshal.SizeOf(managedType);
buffer = Marshal.AllocHGlobal((int)propBufSize);
Marshal.WriteByte(buffer, value);
}
/*
* // (U)Int16
* if (managedType == typeof(short)
|| managedType == typeof(ushort))
|| return (T) (object) (ushort) Marshal.ReadInt16(buffer);
*/
// (U)Int32
if (managedType == typeof(int) ||
managedType == typeof(uint))
{
var value = (uint)(object)propertyValue;
propBufSize = (uint)Marshal.SizeOf(managedType);
buffer = Marshal.AllocHGlobal((int)propBufSize);
Marshal.WriteInt32(buffer, (int)value);
}
/*
* // (U)Int64
* if (managedType == typeof(long)
|| managedType == typeof(ulong))
|| return (T) (object) (ulong) Marshal.ReadInt64(buffer);
||
||// FILETIME/DateTimeOffset
||if (managedType == typeof(DateTimeOffset))
|| return (T) (object) DateTimeOffset.FromFileTime(Marshal.ReadInt64(buffer));
*/
#endregion
if (buffer == IntPtr.Zero)
{
throw new NotImplementedException("Type not supported.");
}
try
{
var ret = SetupApiWrapper.CM_Set_DevNode_Property(
_instanceHandle,
ref nativePropKey,
nativePropType,
buffer,
propBufSize,
0
);
if (ret != SetupApiWrapper.ConfigManagerResult.Success)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
finally
{
Marshal.FreeHGlobal(buffer);
}
}
