Flowchart

AIStudio.Wpf.Flowchart/Models/DiagramDataConverter.cs

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+using System;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace AIStudio.Wpf.Flowchart.Models
+{
+    public class DiagramNodeConverter : DATACreationConverter<DiagramNode>
+    {
+        protected override DiagramNode Create(Type objectType, JObject jObject)
+        {
+            //第一种方法：判断属性值来确认是哪个派生类 
+            if (FieldExists("Type", jObject, out string type))
+            {
+                if (type == "FlowchartNode")
+                {
+                    return new FlowchartNode();
+                }
+                else
+                {
+                    return new DiagramNode();
+                }
+            }
+            else
+            {
+                return new DiagramNode();
+            }
+
+            //第二种方法：判断字段是否存在来确认是哪个派生类
+        }
+
+        private bool FieldExists(string fieldName, JObject jObject, out string entityName)
+        {
+            entityName = jObject[fieldName] == null ? "" : jObject[fieldName].ToString();
+            return jObject[fieldName] != null;
+        }
+    }
+
+    public class DiagramLinkConverter : DATACreationConverter<DiagramLink>
+    {
+        protected override DiagramLink Create(Type objectType, JObject jObject)
+        {
+            //第一种方法：判断属性值来确认是哪个派生类 
+            if (FieldExists("Type", jObject, out string type))
+            {
+                return new DiagramLink();
+            }
+            else
+            {
+                return new DiagramLink();
+            }
+
+            //第二种方法：判断字段是否存在来确认是哪个派生类
+        }
+
+        private bool FieldExists(string fieldName, JObject jObject, out string entityName)
+        {
+            entityName = jObject[fieldName] == null ? "" : jObject[fieldName].ToString();
+            return jObject[fieldName] != null;
+        }
+    }
+
+    public abstract class DATACreationConverter<T> : JsonConverter
+    {
+        /// <summary>
+        /// Create an instance of objectType, based properties in the JSON object
+        /// </summary>
+        /// <param name="objectType">type of object expected</param>
+        /// <param name="jObject">
+        /// contents of JSON object that will be deserialized
+        /// </param>
+        /// <returns></returns>
+        protected abstract T Create(Type objectType, JObject jObject);
+
+        public override bool CanConvert(Type objectType)
+        {
+            return typeof(T).IsAssignableFrom(objectType);
+        }
+
+        public override object ReadJson(JsonReader reader,
+                                        Type objectType,
+                                         object existingValue,
+                                         JsonSerializer serializer)
+        {
+            // Load JObject from stream
+            JObject jObject = JObject.Load(reader);
+
+            // Create target object based on JObject
+            T target = Create(objectType, jObject);
+
+            // Populate the object properties
+            serializer.Populate(jObject.CreateReader(), target);
+
+            return target;
+        }
+
+        public override void WriteJson(JsonWriter writer,
+                                       object value,
+                                       JsonSerializer serializer)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}