GodSharp.Opc.Da.OpcNetApi库opcda源码

以下是GodSharp.Opc.Da.OpcNetApi库中opcda的源码示例：

public class OpcDa : IDisposable
{
    private const int ShutdownTimeout = 10000;

    private readonly object _lockObject = new object();

    private readonly OpcServer _server;
    private readonly IOPCServer _opcServer;
    private readonly IConnectionPoint _connectionPoint;
    private readonly OPCShutdown _opcShutdown;

    private readonly Dictionary<int, OpcGroup> _groups = new Dictionary<int, OpcGroup>();
    private int _groupId;

    private bool _disposed;

    public OpcDa(string host)
    {
        _server = new OpcServer();
        _server.Connect(host);
        _opcServer = _server.GetOPCServer();
        _opcShutdown = new OPCShutdown(this);
        var cpContainer = (IConnectionPointContainer)_opcServer;
        var cpGuid = typeof(IOPCShutdown).GUID;
        cpContainer.FindConnectionPoint(ref cpGuid, out _connectionPoint);
        _connectionPoint.Advise(_opcShutdown, out var cookie);
    }

    public void Dispose()
    {
        lock (_lockObject)
        {
            if (_disposed)
            {
                return;
            }

            _disposed = true;

            _connectionPoint.Unadvise(_opcShutdown.Cookie);

            foreach (var group in _groups.Values)
            {
                group.Dispose();
            }

            _server.Disconnect(ShutdownTimeout);
        }
    }

    public OpcGroup AddGroup(string name, int updateRate)
    {
        lock (_lockObject)
        {
            var group = new OpcGroup(this, ++_groupId, name, updateRate);
            _groups.Add(group.GroupId, group);
            return group;
        }
    }

    public void RemoveGroup(OpcGroup group)
    {
        lock (_lockObject)
        {
            if (_groups.TryGetValue(group.GroupId, out var target))
            {
                target.Dispose();
                _groups.Remove(target.GroupId);
            }
        }
    }

    public IOPCItemProperties GetItemProperties()
    {
        _opcServer.QueryInterface(typeof(IOPCItemProperties).GUID, out var itemProperties);
        return (IOPCItemProperties)itemProperties;
    }

    public IOPCBrowseServerAddressSpace GetBrowser()
    {
        _opcServer.QueryInterface(typeof(IOPCBrowseServerAddressSpace).GUID, out var browser);
        return (IOPCBrowseServerAddressSpace)browser;
    }

    public void ShutdownRequest()
    {
        Dispose();
    }

    internal IOPCServer OpcServer => _opcServer;

    internal void RemoveGroup(int groupId)
    {
        lock (_lockObject)
        {
            if (_groups.TryGetValue(groupId, out var target))
            {
                target.Dispose();
                _groups.Remove(target.GroupId);
            }
        }
    }

    private class OPCShutdown : IOPCShutdown
    {
        private readonly OpcDa _parent;

        public OPCShutdown(OpcDa parent)
        {
            _parent = parent;
        }

        public int Cookie { get; private set; }

        public void ShutdownRequest(string reason)
        {
            _parent.ShutdownRequest();
        }
    }
}

该类提供了与OPC DA服务器通信的功能。它使用OpcServer对象连接到OPC服务器，并提供添加/删除组以及获取ItemProperties和Browser的功能。在Dispose方法中，它释放了与OPC服务器的连接并释放了所有组。 OPCShutdown类用于处理OPC服务器关闭请求。