丰富P39注释

Author: Surbowl

Routine/Routine.APi/Helpers/ObjectExtensions.cs

@@ -1,45 +1,48 @@
 using System;
 using System.Collections.Generic;
 using System.Dynamic;
-using System.Linq;
 using System.Reflection;
-using System.Threading.Tasks;
 
 namespace Routine.APi.Helpers
 {
     //Object 的拓展方法
     //用于查询单个数据时的数据塑形（视频P39）
     public static class ObjectExtensions
     {
-        public static ExpandoObject ShapeData<TSource>(this TSource source,string fields)
+        public static ExpandoObject ShapeData<TSource>(this TSource source, string fields)
         {
             if (source == null)
             {
                 throw new ArgumentNullException(nameof(source));
             }
 
+            //理解 ExpandoObject 的使用 https://blog.csdn.net/u010178308/article/details/79773704
             var expandoObj = new ExpandoObject();
 
+            //如果没有 fields 字符串指定属性，返回所有属性
             if (string.IsNullOrWhiteSpace(fields))
             {
-                var propertyInfos = typeof(TSource).GetProperties(BindingFlags.IgnoreCase 
-                                                                  | BindingFlags.Public 
+                //获得 TSource 的属性
+                var propertyInfos = typeof(TSource).GetProperties(BindingFlags.IgnoreCase  //忽略属性名大小写
+                                                                  | BindingFlags.Public    //搜索公共成员
                                                                   | BindingFlags.Instance);
-                foreach(var propertyInfo in propertyInfos)
+                foreach (var propertyInfo in propertyInfos)
                 {
                     var propertyValue = propertyInfo.GetValue(source);
                     ((IDictionary<string, object>)expandoObj).Add(propertyInfo.Name, propertyValue);
                 }
             }
+            //如果有 fields 字符串指定属性，返回指定的属性
             else
             {
                 var fieldsAfterSpilt = fields.Split(",");
-                foreach(var field in fieldsAfterSpilt)
+                foreach (var field in fieldsAfterSpilt)
                 {
                     var propertyName = field.Trim();
+                    //获得 fields 字符串指定的 TSource 中的各属性
                     var propertyInfo = typeof(TSource).GetProperty(propertyName,
-                                                                   BindingFlags.IgnoreCase
-                                                                  | BindingFlags.Public
+                                                                   BindingFlags.IgnoreCase  //忽略属性名大小写
+                                                                  | BindingFlags.Public     //搜索公共成员
                                                                   | BindingFlags.Instance);
                     if (propertyInfo == null)
                     {
@@ -54,4 +57,4 @@ public static ExpandoObject ShapeData<TSource>(this TSource source,string fields
             return expandoObj;
         }
     }
-}
+}