1     public class TestA
 2     {
 3         public int Id { get; set; }
 4         public string Name { get; set; }
 5 
 6         public TestC TestClass { get; set; }
 7 
 8         public IEnumerable<TestC> TestLists { get; set; }
 9     }
10 
11     public class TestB
12     {
13         public int Id { get; set; }
14         public string Name { get; set; }
15 
16         public TestD TestClass { get; set; }
17 
18         public TestD[] TestLists { get; set; }
19     }
20 
21     public class TestC
22     {
23         public int Id { get; set; }
24         public string Name { get; set; }
25 
26         public TestC SelfClass { get; set; }
27     }
28 
29     public class TestD
30     {
31         public int Id { get; set; }
32         public string Name { get; set; }
33 
34         public TestD SelfClass { get; set; }
35     }

 1       private static Func<TSource, TTarget> GetMap<TSource, TTarget>()
 2         {
 3             var sourceType = typeof(TSource);
 4             var targetType = typeof(TTarget);
 5 
 6             //构造 p=>
 7             var parameterExpression = Expression.Parameter(sourceType, "p");
 8 
 9             //构造 p=>new TTarget{ Id=p.Id,Name=p.Name };
10             var memberBindingList = new List<MemberBinding>();
11             foreach (var sourceItem in sourceType.GetProperties())
12             {
13                 var targetItem = targetType.GetProperty(sourceItem.Name);
14                 if (targetItem == null || sourceItem.PropertyType != targetItem.PropertyType)
15                     continue;
16 
17                 var property = Expression.Property(parameterExpression, sourceItem);
18                 var memberBinding = Expression.Bind(targetItem, property);
19                 memberBindingList.Add(memberBinding);
20             }
21             var memberInitExpression = Expression.MemberInit(Expression.New(targetType), memberBindingList);
22 
23             var lambda = Expression.Lambda<Func<TSource, TTarget>>(memberInitExpression, parameterExpression );
24 
25             Console.WriteLine(lambda);
26             return lambda.Compile();
27         }

14 
15     class Program
16     {
17         static void Main(string[] args)
18         {
19             var testA = new TestA { Id = 1, Name = "张三" };
20             var func = Map<TestA, TestB>();
21             TestB testB = func(testA);
22             Console.WriteLine($"testB.Id={testB.Id},testB.Name={testB.Name}");
23             Console.ReadLine();
24         }
25     }

 1     public class DataMapper<TSource, TTarget>
 2     {
 3         private static Func<TSource, TTarget> MapFunc { get; set; }
 4 
 5         public static TTarget Map(TSource source)
 6         {
 7             if (MapFunc == null)
 8                 MapFunc = GetMap();//方法在上边
 9             return MapFunc(source);
10         }11    }

1         static void Main(string[] args)
2         {
3             var testA = new TestA { Id = 1, Name = "张三" };
4             TestB testB = DataMapper<TestA, TestB>.Map(testA);//委托不存在时自动生成，存在时调用静态缓存
5 
6             Console.WriteLine($"testB.Id={testB.Id},testB.Name={testB.Name}");
7             Console.ReadLine();
8         }

 1 public TestB GetTestB(TestA testA)
 2         {
 3             TestB testB;
 4             if (testA != null)
 5             {
 6                 testB = new TestB();
 7                 testB.Id = testA.Id;
 8                 testB.Name = testA.Name;
 9                 if (testA.TestClass != null)
10                 {
11                     testB.TestClass = new TestD();
12                     testB.TestClass.Id = testA.TestClass.Id;
13                     testB.TestClass.Name = testA.TestClass.Name;
14                 }
15             }
16             else
17             {
18                 testB = null;
19             }
20             return testB;
21         }

 1         private static Func<TSource, TTarget> GetMap()
 2         {
 3             var sourceType = typeof(TSource);
 4             var targetType = typeof(TTarget);
 5 
 6             //Func委托传入变量
 7             var parameter = Expression.Parameter(sourceType);
 8 
 9             //声明一个返回值变量
10             var variable = Expression.Variable(targetType);
11             //创建一个if条件表达式
12             var test = Expression.NotEqual(parameter, Expression.Constant(null, sourceType));// p==null;
13             var ifTrue = Expression.Block(GetExpression(parameter, variable, sourceType, targetType));
14             var IfThen = Expression.IfThen(test, ifTrue);
15 
16             //构造代码块 
17             var block = Expression.Block(new[] { variable }, parameter, IfThen, variable);
18 
19             var lambda = Expression.Lambda<Func<TSource, TTarget>>(block, parameter);
20             return lambda.Compile();
21         }
22 
23         private static List<Expression> GetExpression(Expression parameter, Expression variable, Type sourceType, Type targetType)
24         {
25             //创建一个表达式集合
26             var expressions = new List<Expression>();
27 
28             expressions.Add(Expression.Assign(variable, Expression.MemberInit(Expression.New(targetType))));
29 
30             foreach (var targetItem in targetType.GetProperties().Where(x => x.PropertyType.IsPublic && x.CanWrite))
31             {
32                 var sourceItem = sourceType.GetProperty(targetItem.Name);
33 
34                 //判断实体的读写权限
35                 if (sourceItem == null || !sourceItem.CanRead || sourceItem.PropertyType.IsNotPublic)
36                     continue;
37 
38                 var sourceProperty = Expression.Property(parameter, sourceItem);
39                 var targetProperty = Expression.Property(variable, targetItem);
40 
41                 //判断都是class 且类型不相同时
42                 if (targetItem.PropertyType.IsClass && sourceItem.PropertyType.IsClass && targetItem.PropertyType != sourceItem.PropertyType)
43                 {
44                     if (targetItem.PropertyType != targetType)//不处理嵌套循环的情况
45                     {
46                         //由于类型是class 所以默认值是null
47                         var testItem = Expression.NotEqual(sourceProperty, Expression.Constant(null, sourceItem.PropertyType));
48 
49                         var itemExpressions = GetExpression(sourceProperty, targetProperty, sourceItem.PropertyType, targetItem.PropertyType);
50                         var ifTrueItem = Expression.Block(itemExpressions);
51 
52                         var IfThenItem = Expression.IfThen(testItem, ifTrueItem);
53                         expressions.Add(IfThenItem);
54 
55                         continue;
56                     }
57                 }
58 
59                 //目标值类型时 且两者类型不一致时跳过
60                 if (targetItem.PropertyType != sourceItem.PropertyType)
61                     continue;
62 
63                 expressions.Add(Expression.Assign(targetProperty, sourceProperty));
64             }
65 
66             return expressions;
67         }

  using static System.Linq.Expressions.Expression;
    public static class Mapper<TSource, TTarget> where TSource : class where TTarget : class
    {
public readonly static Func<TSource, TTarget> MapFunc = GetMapFunc();

public readonly static Action<TSource, TTarget> MapAction = GetMapAction();

/// <summary>
/// 将对象TSource转换为TTarget
/// </summary>
/// <param name="source"></param>
/// <returns></returns>
public static TTarget Map(TSource source) => MapFunc(source);

public static List<TTarget> MapList(IEnumerable<TSource> sources)=> sources.Select(MapFunc).ToList();



/// <summary>
/// 将对象TSource的值赋给给TTarget
/// </summary>
/// <param name="source"></param>
/// <param name="target"></param>
public static void Map(TSource source, TTarget target) => MapAction(source, target);

private static Func<TSource, TTarget> GetMapFunc()
        {
            var sourceType = typeof(TSource);
            var targetType = typeof(TTarget);
            //Func委托传入变量
            var parameter = Parameter(sourceType, "p");

            var memberBindings = new List<MemberBinding>();
            var targetTypes = targetType.GetProperties().Where(x => x.PropertyType.IsPublic && x.CanWrite);
            foreach (var targetItem in targetTypes)
            {
                var sourceItem = sourceType.GetProperty(targetItem.Name);

                //判断实体的读写权限
                if (sourceItem == null || !sourceItem.CanRead || sourceItem.PropertyType.IsNotPublic)
                    continue;

                //标注NotMapped特性的属性忽略转换
                if (sourceItem.GetCustomAttribute<NotMappedAttribute>() != null)
                    continue;

                var sourceProperty = Property(parameter, sourceItem);

                //当非值类型且类型不相同时
                if (!sourceItem.PropertyType.IsValueType && sourceItem.PropertyType != targetItem.PropertyType)
                {
                    //判断都是(非泛型)class
                    if (sourceItem.PropertyType.IsClass && targetItem.PropertyType.IsClass &&
                        !sourceItem.PropertyType.IsGenericType && !targetItem.PropertyType.IsGenericType)
                    {
                        var expression = GetClassExpression(sourceProperty, sourceItem.PropertyType, targetItem.PropertyType);
                        memberBindings.Add(Bind(targetItem, expression));
                    }

                    //集合数组类型的转换
                    if (typeof(IEnumerable).IsAssignableFrom(sourceItem.PropertyType) && typeof(IEnumerable).IsAssignableFrom(targetItem.PropertyType))
                    {
                        var expression = GetListExpression(sourceProperty, sourceItem.PropertyType, targetItem.PropertyType);
                        memberBindings.Add(Bind(targetItem, expression));
                    }

                    continue;
                }

                if (targetItem.PropertyType != sourceItem.PropertyType)
                    continue;

                memberBindings.Add(Bind(targetItem, sourceProperty));
            }

            //创建一个if条件表达式
            var test = NotEqual(parameter, Constant(null, sourceType));// p==null;
            var ifTrue = MemberInit(New(targetType), memberBindings);
            var condition = Condition(test, ifTrue, Constant(null, targetType));

            var lambda = Lambda<Func<TSource, TTarget>>(condition, parameter);
            return lambda.Compile();
        }

        /// <summary>
        /// 类型是clas时赋值
        /// </summary>
        /// <param name="sourceProperty"></param>
        /// <param name="targetProperty"></param>
        /// <param name="sourceType"></param>
        /// <param name="targetType"></param>
        /// <returns></returns>
        private static Expression GetClassExpression(Expression sourceProperty, Type sourceType, Type targetType)
        {
            //条件p.Item!=null    
            var testItem = NotEqual(sourceProperty, Constant(null, sourceType));

            //构造回调 Mapper<TSource, TTarget>.Map()
            var mapperType = typeof(Mapper<,>).MakeGenericType(sourceType, targetType);
            var iftrue = Call(mapperType.GetMethod(nameof(Map), new[] { sourceType }), sourceProperty);

            var conditionItem = Condition(testItem, iftrue, Constant(null, targetType));

            return conditionItem;
        }

        /// <summary>
        /// 类型为集合时赋值
        /// </summary>
        /// <param name="sourceProperty"></param>
        /// <param name="targetProperty"></param>
        /// <param name="sourceType"></param>
        /// <param name="targetType"></param>
        /// <returns></returns>
        private static Expression GetListExpression(Expression sourceProperty, Type sourceType, Type targetType)
        {
            //条件p.Item!=null    
            var testItem = NotEqual(sourceProperty, Constant(null, sourceType));

            //构造回调 Mapper<TSource, TTarget>.MapList()
            var sourceArg = sourceType.IsArray ? sourceType.GetElementType() : sourceType.GetGenericArguments()[0];
            var targetArg = targetType.IsArray ? targetType.GetElementType() : targetType.GetGenericArguments()[0];
            var mapperType = typeof(Mapper<,>).MakeGenericType(sourceArg, targetArg);

            var mapperExecMap = Call(mapperType.GetMethod(nameof(MapList), new[] { sourceType }), sourceProperty);

            Expression iftrue;
            if (targetType == mapperExecMap.Type)
            {
                iftrue = mapperExecMap;
            }
            else if (targetType.IsArray)//数组类型调用ToArray()方法
            {
                iftrue = Call(mapperExecMap, mapperExecMap.Type.GetMethod("ToArray"));
            }
            else if (typeof(IDictionary).IsAssignableFrom(targetType))
            {
                iftrue = Constant(null, targetType);//字典类型不转换
            }
            else
            {
                iftrue = Convert(mapperExecMap, targetType);
            }

            var conditionItem = Condition(testItem, iftrue, Constant(null, targetType));

            return conditionItem;
        }

        private static Action<TSource, TTarget> GetMapAction()
        {
            var sourceType = typeof(TSource);
            var targetType = typeof(TTarget);
            //Func委托传入变量
            var sourceParameter = Parameter(sourceType, "p");

            var targetParameter = Parameter(targetType, "t");

            //创建一个表达式集合
            var expressions = new List<Expression>();

            var targetTypes = targetType.GetProperties().Where(x => x.PropertyType.IsPublic && x.CanWrite);
            foreach (var targetItem in targetTypes)
            {
                var sourceItem = sourceType.GetProperty(targetItem.Name);

                //判断实体的读写权限
                if (sourceItem == null || !sourceItem.CanRead || sourceItem.PropertyType.IsNotPublic)
                    continue;

                //标注NotMapped特性的属性忽略转换
                if (sourceItem.GetCustomAttribute<NotMappedAttribute>() != null)
                    continue;

                var sourceProperty = Property(sourceParameter, sourceItem);
                var targetProperty = Property(targetParameter, targetItem);

                //当非值类型且类型不相同时
                if (!sourceItem.PropertyType.IsValueType && sourceItem.PropertyType != targetItem.PropertyType)
                {
                    //判断都是(非泛型)class
                    if (sourceItem.PropertyType.IsClass && targetItem.PropertyType.IsClass &&
                        !sourceItem.PropertyType.IsGenericType && !targetItem.PropertyType.IsGenericType)
                    {
                        var expression = GetClassExpression(sourceProperty, sourceItem.PropertyType, targetItem.PropertyType);
                        expressions.Add(Assign(targetProperty, expression));
                    }

                    //集合数组类型的转换
                    if (typeof(IEnumerable).IsAssignableFrom(sourceItem.PropertyType) && typeof(IEnumerable).IsAssignableFrom(targetItem.PropertyType))
                    {
                        var expression = GetListExpression(sourceProperty, sourceItem.PropertyType, targetItem.PropertyType);
                        expressions.Add(Assign(targetProperty, expression));
                    }

                    continue;
                }

                if (targetItem.PropertyType != sourceItem.PropertyType)
                    continue;


                expressions.Add(Assign(targetProperty, sourceProperty));
            }

            //当Target!=null判断source是否为空
            var testSource = NotEqual(sourceParameter, Constant(null, sourceType));
            var ifTrueSource = Block(expressions);
            var conditionSource = IfThen(testSource, ifTrueSource);

            //判断target是否为空
            var testTarget = NotEqual(targetParameter, Constant(null, targetType));
            var conditionTarget = IfThen(testTarget, conditionSource);

            var lambda = Lambda<Action<TSource, TTarget>>(conditionTarget, sourceParameter, targetParameter);
            return lambda.Compile();
        }
    }

 1 p => IIF((p != null), 
 2      new TestB() 
 3      {
 4        Id = p.Id, 
 5        Name = p.Name, 
 6        TestClass = IIF(
 7                    (p.TestClass != null),
 8                     Map(p.TestClass),
 9                     null
10                     ),
11        TestLists = IIF(
12                      (p.TestLists != null),
13                       MapList(p.TestLists).ToArray(),
14                       null
15                      )
16        },
17        null)

  1     public static class MapperTest
  2     {
  3         //执行次数
  4         public static int Count = 100000;
  5 
  6         //简单类型
  7         public static void Nomal()
  8         {
  9             Console.WriteLine($"******************简单类型:{Count / 10000}万次执行时间*****************");
 10             var model = new TestA
 11             {
 12                 Id =1,
 13                 Name = "张三",
 14             };
 15 
 16             //计时
 17             var sw = Stopwatch.StartNew();
 18             for (int i = 0; i < Count; i++)
 19             {
 20                 if (model != null)
 21                 {
 22                     var b = new TestB
 23                     {
 24                         Id = model.Id,
 25                         Name = model.Name,
 26                     };
 27                 }
 28             }
 29             sw.Stop();
 30             Console.WriteLine($"原生的时间:{sw.ElapsedMilliseconds}ms");
 31 
 32             Exec(model);
 33         }
 34 
 35         //复杂类型
 36         public static void Complex()
 37         {
 38             Console.WriteLine($"********************复杂类型:{Count / 10000}万次执行时间*********************");
 39             var model = new TestA
 40             {
 41                 Id = 1,
 42                 Name = "张三",
 43                 TestClass = new TestC
 44                 {
 45                     Id = 2,
 46                     Name = "lisi",
 47                 },
 48             };
 49 
 50             //计时
 51             var sw = Stopwatch.StartNew();
 52             for (int i = 0; i < Count; i++)
 53             {
 54 
 55                 if (model != null)
 56                 {
 57                     var b = new TestB
 58                     {
 59                         Id = model.Id,
 60                         Name = model.Name,
 61                     };
 62                     if (model.TestClass != null)
 63                     {
 64                         b.TestClass = new TestD
 65                         {
 66                             Id = i,
 67                             Name = "lisi",
 68                         };
 69                     }
 70                 }
 71             }
 72             sw.Stop();
 73             Console.WriteLine($"原生的时间:{sw.ElapsedMilliseconds}ms");
 74             Exec(model);
 75         }
 76 
 77         //嵌套类型
 78         public static void Nest()
 79         {
 80             Console.WriteLine($"*****************嵌套类型:{Count / 10000}万次执行时间*************************");
 81             var model = new TestA
 82             {
 83                 Id = 1,
 84                 Name = "张三",
 85                 TestClass = new TestC
 86                 {
 87                     Id = 1,
 88                     Name = "lisi",
 89                     SelfClass = new TestC
 90                     {
 91                         Id = 2,
 92                         Name = "lisi",
 93                         SelfClass = new TestC
 94                         {
 95                             Id = 3,
 96                             Name = "lisi",
 97                             SelfClass = new TestC
 98                             {
 99                                 Id = 4,
100                                 Name = "lisi",
101                             },
102                         },
103                     },
104                 },
105             };
106             //计时
107             var item = model;
108             var sw = Stopwatch.StartNew();
109             for (int i = 0; i < Count; i++)
110             {
111                 //这里每一步需要做非空判断的，书写太麻烦省去了
112                 if (model != null)
113                 {
114                     var b = new TestB
115                     {
116                         Id = model.Id,
117                         Name = model.Name,
118                         TestClass = new TestD
119                         {
120                             Id = model.TestClass.Id,
121                             Name = model.TestClass.Name,
122                             SelfClass = new TestD
123                             {
124                                 Id = model.TestClass.SelfClass.Id,
125                                 Name = model.TestClass.SelfClass.Name,
126                                 SelfClass = new TestD
127                                 {
128                                     Id = model.TestClass.SelfClass.SelfClass.Id,
129                                     Name = model.TestClass.SelfClass.SelfClass.Name,
130                                     SelfClass = new TestD
131                                     {
132                                         Id = model.TestClass.SelfClass.SelfClass.SelfClass.Id,
133                                         Name = model.TestClass.SelfClass.SelfClass.SelfClass.Name,
134                                     },
135                                 },
136                             },
137                         },
138                     };
139                 }
140             }
141             sw.Stop();
142             Console.WriteLine($"原生的时间:{sw.ElapsedMilliseconds}ms");
143 
144             Exec(model);
145         }
146 
147         //集合
148         public static void List()
149         {
150             Console.WriteLine($"********************集合类型:{Count/10000}万次执行时间***************************");
151 
152             var model = new TestA
153             {
154                 Id = 1,
155                 Name = "张三",
156                 TestLists = new List<TestC> {
157                             new TestC{
158                              Id = 1,
159                             Name =  "张三",
160                            },
161                             new TestC{
162                             Id = -1,
163                             Name =  "张三",
164                            },
165                         }
166             };
167 
168 
169             //计时
170             var sw = Stopwatch.StartNew();
171             for (int i = 0; i < Count; i++)
172             {
173                 var item = model;
174                 if (item != null)
175                 {
176                     var b = new TestB
177                     {
178                         Id = item.Id,
179                         Name = item.Name,
180                         TestLists = new List<TestD> {
181                             new TestD{
182                                    Id = item.Id,
183                             Name = item.Name,
184                            },
185                             new TestD{
186                             Id = -item.Id,
187                             Name = item.Name,
188                            },
189                         }.ToArray()
190                     };
191                 }
192             }
193             sw.Stop();
194             Console.WriteLine($"原生的时间:{sw.ElapsedMilliseconds}ms");
195 
196             Exec(model);
197         }
198 
199         public static void Exec(TestA model)
200         {
201             //表达式
202             Mapper<TestA, TestB>.Map(model);
203             var sw = Stopwatch.StartNew();
204             for (int i = 0; i < Count; i++)
205             {
206                 var b = Mapper<TestA, TestB>.Map(model);
207             }
208             sw.Stop();
209             Console.WriteLine($"表达式的时间:{sw.ElapsedMilliseconds}ms");
210 
211             //AutoMapper
212             sw.Restart();
213             for (int i = 0; i < Count; i++)
214             {
215                 var b = AutoMapper.Mapper.Map<TestA, TestB>(model);
216             }
217             sw.Stop();
218             Console.WriteLine($"AutoMapper时间:{sw.ElapsedMilliseconds}ms");
219 
220             //TinyMapper
221             sw.Restart();
222             for (int i = 0; i < Count; i++)
223             {
224                 var b = TinyMapper.Map<TestA, TestB>(model);
225             }
226             sw.Stop();
227             Console.WriteLine($"TinyMapper时间:{sw.ElapsedMilliseconds}ms");
228         }
229     }
230 
231

 1         static void Main(string[] args)
 2         {
 3             AutoMapper.Mapper.Initialize(cfg => cfg.CreateMap<TestA, TestB>());
 4             TinyMapper.Bind<TestA, TestB>();
 5             Mapper<TestA, TestB>.Map(new TestA());
 6 
 7 
 8             MapperTest.Count = 10000;
 9             MapperTest.Nomal();
10             MapperTest.Complex();
11             MapperTest.Nest();
12             MapperTest.List();
13 
14             MapperTest.Count = 100000;
15             MapperTest.Nomal();
16             MapperTest.Complex();
17             MapperTest.Nest();
18             MapperTest.List();
19 
20             MapperTest.Count = 1000000;
21             MapperTest.Nomal();
22             MapperTest.Complex();
23             MapperTest.Nest();
24             MapperTest.List();
25 
26             MapperTest.Count = 10000000;
27             MapperTest.Nomal();
28             MapperTest.Complex();
29             MapperTest.Nest();
30             MapperTest.List();
31 
32 
33             Console.WriteLine($"------------结束--------------------");
34             Console.ReadLine();
35         }

 1     public class Students
 2     {
 3         public int No { get; set; }
 4         public string Name { get; set; }
 5         public bool Gender { get; set; }
 6         public string Class { get; set; }
 7 
 8         public string _remark;
 9     }
10 
11     public class StudentsDto
12     {
13         public int No { get; set; }
14         public string Name { get; set; }
15         public bool Gender { get; set; }
16         public string Class { get; set; }
17 
18         public string _remark;
19     }
20 
21     public class Teachers
22     {
23         public int No { get; set; }
24 
25         public string Course { get; set; }
26 
27         public string Name { get; set; }
28     }
29 
30     public class TeachersDto
31     {
32         public int No { get; set; }
33 
34         public string Course { get; set; }
35 
36         public string Name { get; set; }
37     }

 1 StudentsDto studentsDto = new StudentsDto { No = 1, Name = "Epic", Gender = true, Class = "家里蹲一班", _remark = "逗比" };
 2 TeachersDto teachersDto = new TeachersDto { No = 2, Name = "Eleven", Course = ".net" };
 3 Students students = new Students
 4                     {
 5                         No = studentsDto.No,
 6                         Name = studentsDto.Name,
 7                         Gender = studentsDto.Gender,
 8                         Class = studentsDto.Class,
 9                         _remark = studentsDto._remark
10                     };
11  Teachers teachers = new Teachers
12                     {
13                         No = teachersDto.No,
14                         Name = teachersDto.Name,
15                         Course = teachersDto.Course
16                     };

 1     public static TModel Trans<TModel, TModelDto>(TModelDto dto)
 2             where TModel : class
 3             where TModelDto : class
 4         {
 5             TModel model = Activator.CreateInstance(typeof(TModel)) as TModel;
 6             //获取TModel的属性集合
 7             PropertyInfo[] modlePropertys = typeof(TModel).GetProperties();
 8             //获取TModelDto的属性集合
 9             Type type = dto.GetType();
10             PropertyInfo[] propertys = type.GetProperties();
11             foreach (var property in propertys)
12             {
13                 foreach (var mproperty in modlePropertys)
14                 {
15                     //如果属性名称一致，则将该属性值赋值到TModel实例中
16                     //这里可以用Attribute来实现成员的自定义映射
17                     if (property.Name.Equals(mproperty.Name))
18                     {
19                         mproperty.SetValue(model, property.GetValue(dto));
20                         break;
21                     }
22                 }
23             }
24 
25             //获取TModel的字段集合
26             FieldInfo[] modelfieldInfos = typeof(TModel).GetFields();
27             //获取TModelDto的字段集合
28             FieldInfo[] fieldInfos = type.GetFields();
29             foreach (var field in fieldInfos)
30             {
31                 foreach (var mfield in modelfieldInfos)
32                 {
33                     //如果字段名称一致，则将该字段值赋值到TModel实例中
34                     if (field.Name.Equals(mfield.Name))
35                     {
36                         mfield.SetValue(model, field.GetValue(dto));
37                         break;
38                     }
39                 }
40             }
41             return model;
42         }

1 public static TModel Trans<TModel, TModelDto>(TModelDto dto)
2             where TModel : class
3             where TModelDto : class
4         {
5             return JsonConvert.DeserializeObject<TModel>(JsonConvert.SerializeObject(dto));
6         }

 1    public static class ExpressionAndSeesionMethod
 2 
 3     {
 4         public static Dictionary<string, object> _dictionary = new Dictionary<string, object>();
 5 
 6         public static TModel Trans<TModel, TModelDto>(TModelDto dto)
 7         {
 8             Type modelType = typeof(TModel);
 9             Type modelDtoType = typeof(TModelDto);
10 
11             //如果_dictionary中不存在该key，则存进去
12             string key = $"{modelDtoType.Name}-->{modelType.Name}";
13             if (!_dictionary.ContainsKey(key))
14             {
15                 //创建一个lambda参数x，定义的对象为TModelDto
16                 ParameterExpression parameterExpression = Expression.Parameter(modelDtoType, "x");
17                 //开始生成lambda表达式
18                 List<MemberBinding> list = new List<MemberBinding>();
19                 foreach (var item in modelType.GetProperties())
20                 {
21                     //为x参数表达式生成一个属性值
22                     MemberExpression property = Expression.Property(parameterExpression, modelDtoType.GetProperty(item.Name));
23                     //将该属性初始化 eg:No=x.No
24                     MemberBinding memberBinding = Expression.Bind(item, property);
25                     list.Add(memberBinding);
26                 }
27 
28                 foreach (var item in typeof(TModel).GetFields())
29                 {
30                     //为x参数表达式生成一个字段值
31                     MemberExpression field = Expression.Field(parameterExpression, modelDtoType.GetField(item.Name));
32                     //将该字段初始化
33                     MemberBinding memberBinding = Expression.Bind(item, field);
34                     list.Add(memberBinding);
35                 }
36                 //调用构造函数，初始化一个TModel eg: new{No=x.No...}
37                 MemberInitExpression memberInitExpression = Expression.MemberInit(Expression.New(modelType), list);
38                 //创建lambda表达式  eg: x=>new{ No=x.No...}
39                 Expression<Func<TModelDto, TModel>> lambda = Expression.Lambda<Func<TModelDto, TModel>>(memberInitExpression, parameterExpression);
40                 //将lambda表达式生成委托
41                 Func<TModelDto, TModel> func = lambda.Compile();
42                 _dictionary[key] = func;
43             }
44             return ((Func<TModelDto, TModel>)_dictionary[key]).Invoke(dto);
45         }
46     }

 1     /// <summary>
 2     ///泛型委托基于泛型类之上
 3     ///泛型静态类在确定参数类型的时候会调用其静态函数
 4     ///在执行委托时，泛型委托会内置查找相应的委托来执行
 5     /// </summary>
 6     public static class ExpressionAndFuncMethod<TModel, TModelDto>
 7        where TModel : class
 8        where TModelDto : class
 9     {
10         static ExpressionAndFuncMethod()
11         {
12             ExpressionMapper();
13         }
14 
15         public static Func<TModelDto, TModel> _func = null;
16 
17         public static void ExpressionMapper()
18         {
19             Type modelType = typeof(TModel);
20             Type modelDtoType = typeof(TModelDto);
21 
22             //创建一个lambda参数x，定义的对象为TModelDto
23             ParameterExpression parameterExpression = Expression.Parameter(modelDtoType, "x");
24             //开始生成lambda表达式
25             List<MemberBinding> list = new List<MemberBinding>();
26             foreach (var item in modelType.GetProperties())
27             {
28                 //为x参数表达式生成一个属性值
29                 MemberExpression property = Expression.Property(parameterExpression, modelDtoType.GetProperty(item.Name));
30                 //将该属性初始化 eg:No=x.No
31                 MemberBinding memberBinding = Expression.Bind(item, property);
32                 list.Add(memberBinding);
33             }
34 
35             foreach (var item in typeof(TModel).GetFields())
36             {
37                 //为x参数表达式生成一个字段值
38                 MemberExpression field = Expression.Field(parameterExpression, modelDtoType.GetField(item.Name));
39                 //将该字段初始化
40                 MemberBinding memberBinding = Expression.Bind(item, field);
41                 list.Add(memberBinding);
42             }
43             //调用构造函数，初始化一个TModel eg: new{No=x.No...}
44             MemberInitExpression memberInitExpression = Expression.MemberInit(Expression.New(modelType), list);
45             //创建lambda表达式  eg: x=>new{ No=x.No...}
46             Expression<Func<TModelDto, TModel>> lambda = Expression.Lambda<Func<TModelDto, TModel>>(memberInitExpression, parameterExpression);
47             //将lambda表达式生成委托
48             _func = lambda.Compile();
49         }
50 
51         public static TModel Trans(TModelDto dto)
52         {
53             if (_func != null)
54                 return _func(dto);
55             return default(TModel);
56         }
57     }

 1     public static class AutoMapperMethod
 2     {
 3         /// <summary>
 4         /// AutoMapper 必须先创建映射
 5         /// </summary>
 6         /// <param name="dictionary"></param>
 7         public static void Init(Dictionary<Type, Type> dictionary)
 8         {
 9             AutoMapper.Mapper.Initialize(x =>
10             {
11                 foreach (var item in dictionary)
12                 {
13                     x.CreateMap(item.Key, item.Value);
14                 }
15             });
16         }
17 
18 
19         public static TModel Trans<TModel, TModelDto>(TModelDto dto)
20                            where TModel : class
21        where TModelDto : class
22         {
23             return AutoMapper.Mapper.Map<TModelDto, TModel>(dto);
24         }
25     }

    public class Student
    {
        public int Id { get; set; }
        public string Name { get; set; } 
        public int Age { get; set; } 
    }

    public class StudentSecond
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public int Age { get; set; } 
    }

 private static TOut TransReflection<TIn, TOut>(TIn tIn)
        {
            TOut tOut = Activator.CreateInstance<TOut>();
            var tInType = tIn.GetType();
            foreach (var itemOut in tOut.GetType().GetProperties())
            {
                var itemIn = tInType.GetProperty(itemOut.Name); ;
                if (itemIn != null)
                {
                    itemOut.SetValue(tOut, itemIn.GetValue(tIn));
                }
            }
            return tOut;
        }

        Expression<Func<Student, StudentSecond>> ss = (x) => new StudentSecond { Age = x.Age, Id = x.Id, Name = x.Name };
        var f = ss.Compile();
        StudentSecond studentSecond = f(s);

        private static Dictionary<string, object> _Dic = new Dictionary<string, object>();

        private static TOut TransExp<TIn, TOut>(TIn tIn)
        {
            string key = string.Format("trans_exp_{0}_{1}", typeof(TIn).FullName, typeof(TOut).FullName);
            if (!_Dic.ContainsKey(key))
            {
                ParameterExpression parameterExpression = Expression.Parameter(typeof(TIn), "p");
                List<MemberBinding> memberBindingList = new List<MemberBinding>();

                foreach (var item in typeof(TOut).GetProperties())
                {  
　　
　　　　　　　　　　　　if (!item.CanWrite)
　　　　　　　　　　　　　　continue;

                    MemberExpression property = Expression.Property(parameterExpression, typeof(TIn).GetProperty(item.Name));
                    MemberBinding memberBinding = Expression.Bind(item, property);
                    memberBindingList.Add(memberBinding);
                }

                MemberInitExpression memberInitExpression = Expression.MemberInit(Expression.New(typeof(TOut)), memberBindingList.ToArray());
                Expression<Func<TIn, TOut>> lambda = Expression.Lambda<Func<TIn, TOut>>(memberInitExpression, new ParameterExpression[] { parameterExpression });
                Func<TIn, TOut> func = lambda.Compile();

                _Dic[key] = func;
            }
            return ((Func<TIn, TOut>)_Dic[key])(tIn);
        }

 public static class TransExpV2<TIn, TOut>
    {

        private static readonly Func<TIn, TOut> cache = GetFunc();
        private static Func<TIn, TOut> GetFunc()
        {
            ParameterExpression parameterExpression = Expression.Parameter(typeof(TIn), "p");
            List<MemberBinding> memberBindingList = new List<MemberBinding>();

            foreach (var item in typeof(TOut).GetProperties())
            {
　　　　　　　　　if (!item.CanWrite)
　　　　　　　　　　    continue;
                MemberExpression property = Expression.Property(parameterExpression, typeof(TIn).GetProperty(item.Name));
                MemberBinding memberBinding = Expression.Bind(item, property);
                memberBindingList.Add(memberBinding);
            }

            MemberInitExpression memberInitExpression = Expression.MemberInit(Expression.New(typeof(TOut)), memberBindingList.ToArray());
            Expression<Func<TIn, TOut>> lambda = Expression.Lambda<Func<TIn, TOut>>(memberInitExpression, new ParameterExpression[] { parameterExpression });

            return lambda.Compile();
        }

        public static TOut Trans(TIn tIn)
        {
            return cache(tIn);
        }

    }

var context = new MsSqlContext(ConnectionString);

数据查询方法(组件内) => 抽象工厂(组件内) => 抽象实现(组件外)

var builder = new CRL.SettingConfigBuilder();
            builder.UseMongoDB();//引用CRL.Mongo 使用MongoDB
                                 //注册自定义定位,按MemberSharding传入数据定义数据源位置
                                 //注册一
            builder.RegisterLocation<Code.Sharding.MemberSharding>((t, a) =>
            {
                var tableName = t.TableName;
                if (a.Name == "hubro")//当名称为hubro,则定位到库testdb2 表MemberSharding1
                {
                    tableName = "MemberSharding1";
                    return new CRL.Sharding.Location("testdb2", tableName);
                }
                //返回定位库和表名
                return new CRL.Sharding.Location("testdb", tableName);
            });
            //注册二
            builder.RegisterDBAccessBuild(dbLocation =>
            {
                if (dbLocation.ManageName == "mongo")
                {
                    var conn = CRL.Core.CustomSetting.GetConfigKey("mongodb");
                    return new CRL.DBAccessBuild(DBType.MongoDB, conn);
                }
                return null;
            });
            //注册三
            builder.RegisterDBAccessBuild(dbLocation =>
            {
                //自定义定位,由注册一传入
                if (dbLocation.ShardingLocation != null)
                {
                    return new CRL.DBAccessBuild(DBType.MSSQL, "Data Source=.;Initial Catalog=" + dbLocation.ShardingLocation.DataBaseName + ";User ID=sa;Password=123");
                }
                return new CRL.DBAccessBuild(DBType.MSSQL, "server=.;database=testDb; uid=sa;pwd=123;");
            });

public class MemberManage : CRL.Sharding.BaseProvider<MemberSharding>
{
}
var instance=new MemberManage();
instance.Add(new MemberSharding(){Name="hubro"});

建立数据库模型=>导入数据库=>T4模版生成代码(修修补补)

编写实体类,实现对象访问=>调试运行,自动创建表结构(关键字,长度,索引)

var item = instance.QueryItem(b => b.Id==1)

var item = instance.QueryItemFromCache(b=>b.Id==1);

var query = Code.ProductDataManage.Instance.GetLambdaQuery();
//缓存会按条件不同缓存不同的数据,条件不固定时,慎用
query.Where(b => b.Id < 700);
int exp = 10;//过期分钟
query.Expire(exp);
var list = query.ToList();

主查询 => CreateQuery子查询 => 返回匿名对象筛选LambdaQueryResultSelect => 主查询嵌套子查询 => 返回结果

var q1 = Code.OrderManage.Instance.GetLambdaQuery();//主查询
            var q2 = q1.CreateQuery<Code.ProductData>();//创建一个子查询
            q2.Where(b => b.Id > 0);
            var view = q2.CreateQuery<Code.Member>().GroupBy(b => b.Name).Where(b => b.Id > 0).Select(b => new { b.Name, aa = b.Id.COUNT() });//GROUP查询
            var view2 = q2.Join(view, (a, b) => a.CategoryName == b.Name).Select((a, b) => new { ss1 = a.UserId, ss2 = b.aa });//关联GROUP
            q1.Join(view2, (a, b) => a.Id == b.ss1).Select((a, b) => new { a.Id, b.ss1 });//再关联
            var result = view2.ToList();
            var sql = q1.ToString();

SELECT t1.[Id] AS Id,
t2.[ss1] AS ss1
FROM [OrderProduct] t1 with(nolock)
INNER JOIN
(SELECT t2.[UserId] AS ss1,
t3.[aa] AS ss2
FROM [ProductData] t2 with(nolock)
INNER JOIN
(SELECT t3.[Name] AS Name,
COUNT(t3.Id) AS aa
FROM [Member] t3 with(nolock)
WHERE (t3.[Id]>@par1)
GROUP BY t3.[Name]) t3 ON (t2.[CategoryName]=t3.[Name])
WHERE (t2.[Id]>@par0) ) t2 ON (t1.[Id]=t2.[ss1])

CRLLambdaQuery=>CRLExpression=>BsonDocument=>MongoDB

var obj1context.Query<TestEntity>(b=>b.Id==1).ToSingle();

var obj2=context.Query<TestEntity2>(b=>b.Id==1).ToSingle();
var obj3=context.Query<TestEntity3>(b=>b.Id==1).ToSingle();