更新

LinqStudy.Test/LinqStudy.Test.csproj

@@ -20,10 +20,6 @@
 
   <ItemGroup>
     <Folder Include="ExpressionTree\" />
-    <Folder Include="LinqToDataSet\" />
-    <Folder Include="LinqToSQL\" />
-    <Folder Include="LinqToXml\" />
-    <Folder Include="Util\" />
   </ItemGroup>
 
   <ItemGroup>

LinqStudy.Test/LinqToObject/TypeConvertTest.cs

@@ -18,6 +18,7 @@ namespace LinqStudy.Test.LinqToObject
     /// </summary>
     public class TypeConvertTest 
     {
+        #region AsEnumeralbe 
         /// <summary>
         ///  AsEnumeralbe操作符:将IEnumerable<T>输入序列转换成IEnumerable<T>的输出序列
         ///  主要用于将一个实现了IEnumerable<T>接口的对象转换成一个标准的IEnumerable<T>接口对象。
@@ -33,7 +34,9 @@ namespace LinqStudy.Test.LinqToObject
 
             Assert.NotNull(students);
         }
+        #endregion
 
+        #region AsQueryable
         /// <summary>
         /// 主要应用与Linq to sql
         /// </summary>
@@ -42,7 +45,9 @@ namespace LinqStudy.Test.LinqToObject
         {
             //
         }
+        #endregion
 
+        #region OfType
         /// <summary>
         /// OfType：从序列中筛选指定类型的元素，并构建一个序列。
         /// </summary>
@@ -57,7 +62,9 @@ namespace LinqStudy.Test.LinqToObject
 
             Assert.Equal(new List<int>() { 1, 3, 5 }, values.ToList());
         }
+        #endregion
 
+        #region Cast
         /// <summary>
         /// Cast：将数据源中元素，强制转换成指定的类型。
         /// 数据源null或存在不能转换的元素，则异常。
@@ -94,7 +101,9 @@ namespace LinqStudy.Test.LinqToObject
                 ints.Cast<string>().ToList();
             });
         }
+        #endregion
 
+        #region ToList
         /// <summary>
         ///  ToList：将IEnumerable<T>转换为List<T>, 立即执行。
         ///  特别注意：此操作破坏"延迟执行"，变为立即执行；
@@ -145,8 +154,187 @@ namespace LinqStudy.Test.LinqToObject
             //元素对象不是同一个元素
             Assert.NotSame(persons, person2);
         }
+        #endregion
 
+        #region ToDictionary
+        /// <summary>
+        /// ToDictionar转换字典，立即执行并保存快照。
+        /// </summary>
+        [Fact]
+        public void ToDictionary_keySelector_Test()
+        {
+            List<Person> persons = new List<Person>()
+            {
+                new Person() {Id=1, Name="gaofeng",Age = 32 },
+                new Person() {Id=2, Name="zhangsan",Age = 25 },
+            };
+
+            var dic = persons.ToDictionary(p => p.Id);
+
+            Assert.Equal(1, dic[1].Id);
+            Assert.Equal(2, dic[2].Id);
+        }
+
+        [Fact]
+        public void ToDictionary_keySelector_comparer_Test()
+        {
+            List<Person> persons = new List<Person>()
+            {
+                new Person() {Id=1, Name="gaofeng",Age = 32 },
+                new Person() {Id=2, Name="zhangsan",Age = 25 },
+            };
+
+            IEqualityComparer<Person> equal = new PersonEqual();
+
+            var dic = persons.ToDictionary<Person, int>(p => p.Id, EqualityComparer<int>.Default);
 
+            Assert.Equal("gaofeng", dic[1].Name);
+            Assert.Equal("zhangsan", dic[2].Name);
+        }
+
+        [Fact]
+        public void ToDictionary_keySelector_elementSelector_Test()
+        {
+            List<Person> persons = new List<Person>()
+            {
+                new Person() {Id=1, Name="gaofeng",Age = 32 },
+                new Person() {Id=2, Name="zhangsan",Age = 25 },
+            };
+
+            var dic = persons.ToDictionary(p => p.Id, s => s.Name);
+
+            Assert.Equal("gaofeng", dic[1]);
+            Assert.Equal("zhangsan", dic[2]);
+        }
+
+        [Fact]
+        public void ToDictionary_keySelector_elementSelector_comparer_Test()
+        {
+            List<Person> persons = new List<Person>()
+            {
+                new Person() {Id=1, Name="gaofeng",Age = 32 },
+                new Person() {Id=2, Name="zhangsan",Age = 25 },
+            };
+
+            var dic = persons.ToDictionary(p => p.Id, s => s.Name, EqualityComparer<int>.Default);
+
+            Assert.Equal("gaofeng", dic[1]);
+            Assert.Equal("zhangsan", dic[2]);
+        }
+
+        [Fact]
+        public void ToDictionary_ArgumentException_Test()
+        {
+            List<Person> persons = new List<Person>()
+            {
+                new Person() {Id=1, Name="gaofeng",Age = 32 },
+                new Person() {Id=1, Name="zhangsan",Age = 25 },
+            };
+
+            Assert.Throws<ArgumentException>(() => {
+                persons.ToDictionary(p => p.Id, s => s.Name);
+            });
+        }
+
+        [Fact]
+        public void ToDictionary_ArgumentNullException_Test()
+        {
+            List<Person> persons = new List<Person>()
+            {
+                new Person() {Id=1, Name=null,Age = 32 },
+                new Person() {Id=1, Name="zhangsan",Age = 25 },
+            };
+
+            Assert.Throws<ArgumentNullException>(() => {
+                persons.ToDictionary(p => p.Name, s => s.Name);
+            });
+        }
+
+        [Fact]
+        public void ToDictionary_DataSource_NullException_Test()
+        {
+            List<Person> persons = null;
+
+            Assert.Throws<ArgumentNullException>(() => {
+                persons.ToDictionary(p => p.Name, s => s.Name);
+            });
+        }
+        #endregion
+
+        #region ToLookup
+
+        /// <summary>
+        /// ToLookup：根据指定的键选择器函数从IEnumerable<T>创建Lookup<T>
+        /// Lookup<T>对象表示一个一对多的字典，定义了一个由键和序列组成的元组，类似GroupJoin返回的结果。
+        /// </summary>
+        [Fact]
+        public void ToLookup_Test()
+        {
+            var persons = new List<Employee>()
+            {
+                new Employee(){ Id=1, Name="gaofeng",Emails=new List<string>(){"a1@163.com","a2@163.com","a3@163.com"} },
+                new Employee(){ Id=1, Name="zhangsan",Emails=new List<string>(){ "b1@163.com", "b2@163.com", "b3@163.com" } },
+
+                new Employee(){ Id=2, Name="gaofeng2",Emails=new List<string>(){"c1@163.com","c2@163.com","c3@163.com"} },
+                new Employee(){ Id=2, Name="zhangsan2",Emails=new List<string>(){ "d1@163.com", "d2@163.com", "d3@163.com" } },
+            };
+
+            var lookup = persons.ToLookup(q => q.Id);
+            var group2 = lookup[2];
+            var group2_count = group2.Count();
+
+            Assert.Equal(2,group2_count);
+        }
+
+        [Fact]
+        public void ToLookup_keySelector_comparer_Test()
+        {
+            var persons = new List<Employee>()
+            {
+                new Employee(){ Id=1, Name="gaofeng",Emails=new List<string>(){"a1@163.com","a2@163.com","a3@163.com"} },
+                new Employee(){ Id=1, Name="zhangsan",Emails=new List<string>(){ "b1@163.com", "b2@163.com", "b3@163.com" } }
+            };
+
+            var lookup = persons.ToLookup(q => q.Id,EqualityComparer<int>.Default);
+            var group1_firstEmail = lookup[1].FirstOrDefault().Emails.FirstOrDefault() ;
+
+            Assert.Equal("a1@163.com", group1_firstEmail);
+        }
+
+        [Fact]
+        public void ToLookup_keySelector_elementSelector_Test()
+        {
+            var persons = new List<Employee>()
+            {
+                new Employee(){ Id=1, Name="gaofeng",Emails=new List<string>(){"a1@163.com","a2@163.com","a3@163.com"} },
+                new Employee(){ Id=1, Name="zhangsan",Emails=new List<string>(){ "b1@163.com", "b2@163.com", "b3@163.com" } }
+            };
+
+            var lookup = persons.ToLookup(q => q.Id, e=>e.Emails);
+            var group1_Emails = lookup[1].FirstOrDefault();
+            var group1_Emails_first = group1_Emails.FirstOrDefault();
+
+            Assert.Equal("a1@163.com", group1_Emails_first);
+        }
+
+        [Fact]
+        public void ToLookup_keySelector_elementSelector_comparer_Test()
+        {
+            var persons = new List<Employee>()
+            {
+                new Employee(){ Id=1, Name="gaofeng",Emails=new List<string>(){"a1@163.com","a2@163.com","a3@163.com"} },
+                new Employee(){ Id=1, Name="zhangsan",Emails=new List<string>(){ "b1@163.com", "b2@163.com", "b3@163.com" } }
+            };
+
+            var lookup = persons.ToLookup(q => q.Name, e => e.Emails,EqualityComparer<string>.Default);
+            var group1_Emails = lookup["gaofeng"].FirstOrDefault();
+            var group1_Emails_first = group1_Emails.FirstOrDefault();
+
+            Assert.Equal("a1@163.com", group1_Emails_first);
+        }
+        #endregion
+
+        #region private
 
         private DataTable GetDataTable()
         {
@@ -209,6 +397,6 @@ namespace LinqStudy.Test.LinqToObject
 
             return arrStudent;
         }
-
+        #endregion
     }
 }