feat: 实现订阅数据回调功能

Author: ArgoZhang

src/extensions/BootstrapBlazor.OpcDa/ISubscription.cs

@@ -10,13 +10,24 @@ namespace BootstrapBlazor.OpcDa;
 public interface ISubscription
 {
     /// <summary>
-    /// 数据变更回调
+    /// 获得/设置 是否保留最后一个值
     /// </summary>
-    Func<List<OpcReadItem>>? DataChanged { get; set; }
+    public bool KeepLastValue { get; set; }
+
+    /// <summary>
+    /// 获得/设置 数据变更回调
+    /// </summary>
+    Func<List<OpcReadItem>, Task>? DataChanged { get; set; }
 
     /// <summary>
     /// 获得 <see cref="Opc.Da.ISubscription"/> 实例
     /// </summary>
     /// <returns></returns>
     Opc.Da.ISubscription GetSubscription();
+
+    /// <summary>
+    /// 增加数据项
+    /// </summary>
+    /// <param name="items"></param>
+    void AddItems(IEnumerable<string> items);
 }

src/extensions/BootstrapBlazor.OpcDa/OpcSubscription.cs

@@ -6,7 +6,42 @@ namespace BootstrapBlazor.OpcDa;
 
 class OpcSubscription(Opc.Da.ISubscription subscription) : ISubscription
 {
-    public Func<List<OpcReadItem>>? DataChanged { get; set; }
+    public Func<List<OpcReadItem>, Task>? DataChanged { get; set; }
+
+    public bool KeepLastValue { get; set; }
 
     public Opc.Da.ISubscription GetSubscription() => subscription;
+
+    private readonly List<OpcReadItem> _cache = [];
+
+    public void AddItems(IEnumerable<string> items)
+    {
+        var subscription = GetSubscription();
+        subscription.AddItems([.. items.Select(i => new Opc.Da.Item { ItemName = i })]);
+
+        subscription.DataChanged += (_, _, values) =>
+        {
+            var items = values.Select(i =>
+            {
+                var item = new OpcReadItem()
+                {
+                    Name = i.ItemName,
+                    Value = i.Value,
+                    Quality = i.Quality == Opc.Da.Quality.Good ? Quality.Good : Quality.Bad,
+                    Timestamp = i.Timestamp
+                };
+                if (KeepLastValue)
+                {
+                    var v = _cache.Find(i => i.Name == item.Name);
+                    item.LastValue = v.Value;
+                }
+                return item;
+            }).ToList();
+
+            _cache.Clear();
+            _cache.AddRange(items);
+
+            DataChanged?.Invoke(items);
+        };
+    }
 }