private unsafe bool SetCapOneValue(ushort capability, DataTypes type, uint value)
{
ResultCode rc = ResultCode.Failure;
if (state >= TwainState.SourceOpen)
{
TwainStructs.Capability cap = new TwainStructs.Capability();
cap.Cap = capability;
cap.ConType = ContainerType.OneValue;
cap.hContainer = AllocateMemory(Marshal.SizeOf(typeof(TwainStructs.OneValue)));
try
{
if (cap.hContainer != IntPtr.Zero)
{
IntPtr ptr = LockMemory(cap.hContainer);
TwainStructs.OneValue *data = (TwainStructs.OneValue *)ptr.ToPointer();
data->ItemType = type;
data->Item = value;
UnlockMemory(cap.hContainer);
rc = twainCapability(ref appId, ref deviceId, DataGroup.Control, DataArgumentType.Capability, TwainMessages.Set, ref cap);
if (rc == ResultCode.Failure)
{
TwainStructs.Status status = new TwainStructs.Status();
ResultCode src = DSMStatus(ref status);
System.Diagnostics.Debug.Assert(src == ResultCode.Success);
}
}
}
finally
{
if (cap.hContainer != IntPtr.Zero)
{
FreeMemory(cap.hContainer);
cap.hContainer = IntPtr.Zero;
}
}
}
return(rc == ResultCode.Success);
}
private unsafe bool GetCapOneValue(ushort capability, DataTypes type, out object value)
{
value = null;
ResultCode rc = ResultCode.Failure;
if (state >= TwainState.SourceOpen)
{
TwainStructs.Capability cap = new TwainStructs.Capability();
cap.Cap = capability;
cap.ConType = ContainerType.OneValue;
cap.hContainer = IntPtr.Zero;
rc = twainCapability(ref appId, ref deviceId, DataGroup.Control, DataArgumentType.Capability, TwainMessages.GetCurrent, ref cap);
try
{
if (cap.hContainer != IntPtr.Zero)
{
IntPtr ptr = LockMemory(cap.hContainer);
if (cap.ConType == ContainerType.OneValue)
{
TwainStructs.OneValue *pcon = (TwainStructs.OneValue *)ptr.ToPointer();
switch (pcon->ItemType)
{
case DataTypes.Bool:
value = pcon->Item != 0U;
break;
case DataTypes.Int16:
value = (short)pcon->Item;
break;
case DataTypes.UInt16:
value = (ushort)pcon->Item;
break;
case DataTypes.Int32:
value = (int)value;
break;
case DataTypes.UInt32:
value = pcon->Item;
break;
}
}
UnlockMemory(cap.hContainer);
if (rc == ResultCode.Failure)
{
TwainStructs.Status status = new TwainStructs.Status();
ResultCode src = DSMStatus(ref status);
System.Diagnostics.Debug.Assert(src == ResultCode.Success);
}
}
}
finally
{
if (cap.hContainer != IntPtr.Zero)
{
FreeMemory(cap.hContainer);
cap.hContainer = IntPtr.Zero;
}
}
}
return(rc == ResultCode.Success);
}