c# automapper 使用
一、最简单的用法
有两个类User和UserDto
1 public class User
2 {
3 public int Id { get; set; }
4 public string Name { get; set; }
5 public int Age { get; set; }
6 }
7
8 public class UserDto
9 {
10 public string Name { get; set; }
11 public int Age { get; set; }
12 }
将User转换成UserDto也和简单
1 Mapper.Initialize(x => x.CreateMap<User, UserDto>());
2 User user = new User()
3 {
4 Id = 1,
5 Name = "caoyc",
6 Age = 20
7 };
8 var dto = Mapper.Map<UserDto>(user);
这是一种最简单的使用，AutoMapper会更加字段名称去自动对于，忽略大小写。
二、如果属性名称不同
将UserDto的Name属性改成Name2
1 Mapper.Initialize(x =>
2 x.CreateMap<User, UserDto>()
3 .ForMember(d =>d.Name2, opt => {
4 opt.MapFrom(s => s.Name);
5 })
6 );
7
8 User user = new User()
9 {
10 Id = 1,
11 Name = "caoyc",
12 Age = 20
13 };
14
15 var dto = Mapper.Map<UserDto>(user);
三、使用Profile配置
自定义一个UserProfile类继承Profile，并重写Configure方法
1 public class UserProfile : Profile
2 {
3 protected override void Configure()
4 {
5 CreateMap<User, UserDto>()
6 .ForMember(d => d.Name2, opt =>
7 {
8 opt.MapFrom(s => s.Name);
9 });
10 }
11 }
使用时就这样
1 Mapper.Initialize(x => x.AddProfile<UserProfile>());
2
3 User user = new User()
4 {
5 Id = 1,
6 Name = "caoyc",
7 Age = 20
8 };
9
10 var dto = Mapper.Map<UserDto>(user);
四、空值替换NullSubstitute
空值替换允许我们将Source对象中的空值在转换为Destination的值的时候，使用指定的值来替换空值。
1 public class UserProfile : Profile
2 {
3 protected override void Configure()
4 {
5 CreateMap<User, UserDto>()
6 .ForMember(d => d.Name2, opt => opt.MapFrom(s => s.Name))
7 .ForMember(d => d.Name2, opt => opt.NullSubstitute("值为空"));
8
9 }
10 }
1 Mapper.Initialize(x => x.AddProfile<UserProfile>());
2
3 User user = new User()
4 {
5 Id = 1,
6 Age = 20
7 };
8
9 var dto = Mapper.Map<UserDto>(user);
结果为：
五、忽略属性Ignore
1 public class User
2 {
3 public int Id { get; set; }
4 public string Name { get; set; }
5 public int Age { get; set; }
6 }
7
8 public class UserDto
9 {
10 public string Name { get; set; }
11 public int Age { get; set; }
12
13 }
14
15 public class UserProfile : Profile
16 {
17 protected override void Configure()
18 {
19 CreateMap<User, UserDto>().ForMember("Name", opt => opt.Ignore());
20 }
21 }
使用
1 Mapper.Initialize(x => x.AddProfile<UserProfile>());
2
3 User user = new User()
4 {
5 Id = 1,
6 Name="caoyc",
7 Age = 20
8 };
9
10 var dto = Mapper.Map<UserDto>(user);
结果：
六、预设值
如果目标属性多于源属性，可以进行预设值
1 public class User
2 {
3 public int Id { get; set; }
4 public string Name { get; set; }
5 public int Age { get; set; }
6 }
7
8 public class UserDto
9 {
10 public string Name { get; set; }
11 public int Age { get; set; }
12 public string Gender { get; set; }
13
14 }
15
16 public class UserProfile : Profile
17 {
18 protected override void Configure()
19 {
20 CreateMap<User, UserDto>();
21 }
22 }
使用
1 Mapper.Initialize(x => x.AddProfile<UserProfile>());
2
3 User user = new User()
4 {
5 Id = 1,
6 Name="caoyc",
7 Age = 20
8 };
9
10 UserDto dto = new UserDto() {Gender = "男"};
11 Mapper.Map(user, dto);
七、类型转换ITypeConverter
如果数据中Gender存储的int类型，而DTO中Gender是String类型
1 public class User
2 {
3 public int Gender { get; set; }
4 }
5
6 public class UserDto
7 {
8 public string Gender { get; set; }
9 }
类型转换类，需要实现接口ITypeConverter
1 public class GenderTypeConvertert : ITypeConverter<int, string>
2 {
3 public string Convert(int source, string destination, ResolutionContext context)
4 {
5 switch (source)
6 {
7 case 0:
8 destination = "男";
9 break;
10 case 1:
11 destination = "女";
12 break;
13 default:
14 destination = "未知";
15 break;
16 }
17 return destination;
18 }
19 }
配置规则
1 public class UserProfile : Profile
2 {
3 protected override void Configure()
4 {
5 CreateMap<User, UserDto>();
6
7 CreateMap<int, string>().ConvertUsing<GenderTypeConvertert>();
8 //也可以写这样
9 //CreateMap<int, string>().ConvertUsing(new GenderTypeConvertert());
10 }
11 }
使用
1 Mapper.Initialize(x => x.AddProfile<UserProfile>());
2
3 User user0 = new User() { Gender = 0 };
4 User user1 = new User() { Gender = 1 };
5 User user2 = new User() { Gender = 2 };
6 var dto0= Mapper.Map<UserDto>(user0);
7 var dto1 = Mapper.Map<UserDto>(user1);
8 var dto2 = Mapper.Map<UserDto>(user2);
9
10 Console.WriteLine("dto0:{0}", dto0.Gender);
11 Console.WriteLine("dto1:{0}", dto1.Gender);
12 Console.WriteLine("dto2:{0}", dto2.Gender);
结果
八、条件约束Condition
当满足条件时才进行映射字段，例如人类年龄，假设我们现在人类年龄范围为0-200岁（这只是假设），只有满足在这个条件才进行映射
DTO和Entity
1 public class User
2 {
3 public int Age { get; set; }
4 }
5
6 public class UserDto
7 {
8 public int Age { get; set; }
9 }
Profile
1 public class UserProfile : Profile
2 {
3 protected override void Configure()
4 {
5 CreateMap<User, UserDto>().ForMember(dest=>dest.Age,opt=>opt.Condition(src=>src.Age>=0 && src.Age<=200));
6 }
7 }
使用代码
1 Mapper.Initialize(x => x.AddProfile<UserProfile>());
2
3 User user0 = new User() { Age = 1 };
4 User user1 = new User() { Age = 150 };
5 User user2 = new User() { Age = 201 };
6 var dto0= Mapper.Map<UserDto>(user0);
7 var dto1 = Mapper.Map<UserDto>(user1);
8 var dto2 = Mapper.Map<UserDto>(user2);
9
10 Console.WriteLine("dto0:{0}", dto0.Age);
11 Console.WriteLine("dto1:{0}", dto1.Age);
12 Console.WriteLine("dto2:{0}", dto2.Age);
输出结果
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using AutoMapper; using System.Data; namespace ConsoleApplication2 { class Program { static void Main(string[] args) { //1.普通转换 Name name1 = new Name() { FirstName = "L", LastName = "jz" }; Mapper.CreateMap<Name, NameDto>() .BeforeMap((name, nameDto) => Console.WriteLine("hello world before")) .AfterMap((name, nameDto) => Console.WriteLine("hello world after")); NameDto nameDto1 = Mapper.Map<Name, NameDto>(name1); Console.WriteLine("1"); Console.WriteLine(nameDto1.FirstName + nameDto1.LastName); Console.WriteLine(); //Console.ReadKey(); //整体设置 //2.整体即时转换 Mapper.Reset(); Name name2 = new Name() { FirstName = "L", LastName = "jz" }; Mapper.CreateMap<Name, NameDto>() .ConstructUsing(name => new NameDto() { AllName = name.FirstName + name.LastName }); NameDto nameDto2 = Mapper.Map<Name, NameDto>(name2); Console.WriteLine("2"); Console.WriteLine(nameDto2.AllName); Console.WriteLine(); //Console.ReadKey(); //3.整体通过TypeConverter类型转换 Mapper.Reset(); Name name3 = new Name() { FirstName = "L", LastName = "jz" }; Mapper.CreateMap<Name, NameDto>() .ConvertUsing<NameConverter>(); NameDto nameDto3 = Mapper.Map<Name, NameDto>(name3); Console.WriteLine("3"); Console.WriteLine(nameDto3.AllName); Console.WriteLine(); //Console.ReadKey(); //单属性设置 //4.属性条件转换 Mapper.Reset(); Name name4 = new Name() { FirstName = "L", LastName = "jz" }; Mapper.CreateMap<Name, NameDto>() .ForMember(name => name.FirstName, opt => opt.Condition(name => !name.FirstName.Equals("l", StringComparison.OrdinalIgnoreCase))); NameDto nameDto4 = Mapper.Map<Name, NameDto>(name4); Console.WriteLine("4"); Console.WriteLine(string.IsNullOrEmpty(nameDto4.FirstName)); Console.WriteLine(); //Console.ReadKey(); //5.属性忽略 Mapper.Reset(); Name name5 = new Name() { FirstName = "L", LastName = "jz" }; Mapper.CreateMap<Name, NameDto>() .ForMember(name => name.FirstName, opt => opt.Ignore()); NameDto nameDto5 = Mapper.Map<Name, NameDto>(name5); Console.WriteLine("5"); Console.WriteLine(string.IsNullOrEmpty(nameDto5.FirstName)); Console.WriteLine(); //Console.ReadKey(); //6.属性转换 Mapper.Reset(); Name name6 = new Name() { FirstName = "L", LastName = "jz" }; Mapper.CreateMap<Name, NameDto>() .ForMember(name => name.AllName, opt => opt.MapFrom(name => name.FirstName + name.LastName)) .ForMember(name => name.FirstName, opt => opt.MapFrom(name=>name.FirstName)); NameDto nameDto6 = Mapper.Map<Name, NameDto>(name6); Console.WriteLine("6"); Console.WriteLine(nameDto6.AllName); Console.WriteLine(); //Console.ReadKey(); //7.属性通过ValueResolver转换 Mapper.Reset(); Name name7 = new Name() { FirstName = "L", LastName = "jz" }; Mapper.CreateMap<Name, StoreDto>() .ForMember(storeDto => storeDto.Name, opt => opt.ResolveUsing<NameResolver>()); StoreDto store1 = Mapper.Map<Name, StoreDto>(name7); Console.WriteLine("7"); Console.WriteLine(store1.Name.FirstName + store1.Name.LastName); Console.WriteLine(); //Console.ReadKey(); //8.属性填充固定值 Mapper.Reset(); Name name8 = new Name() { FirstName = "L", LastName = "jz" }; Mapper.CreateMap<Name, NameDto>() .ForMember(name => name.AllName, opt => opt.UseValue<string>("ljzforever")); NameDto nameDto8 = Mapper.Map<Name, NameDto>(name8); Console.WriteLine("8"); Console.WriteLine(nameDto8.AllName); Console.WriteLine(); //Console.ReadKey(); //9.属性格式化 Mapper.Reset(); Name name9 = new Name() { FirstName = "L", LastName = "jz" }; Mapper.CreateMap<Name, NameDto>() .ForMember(name => name.FirstName, opt => opt.AddFormatter<StringFormatter>()); NameDto nameDto9 = Mapper.Map<Name, NameDto>(name9); Console.WriteLine("9"); Console.WriteLine(nameDto9.FirstName); Console.WriteLine(); //Console.ReadKey(); //10.属性null时的默认值 Mapper.Reset(); Name name10 = new Name() { FirstName = "L" }; Mapper.CreateMap<Name, NameDto>() .ForMember(name => name.LastName, opt => opt.NullSubstitute("jz")); NameDto nameDto10 = Mapper.Map<Name, NameDto>(name10); Console.WriteLine("10"); Console.WriteLine(nameDto10.LastName); Console.WriteLine(); //Console.ReadKey(); //其它设置与特性 //11.转换匿名对象 Mapper.Reset(); object name11 = new { FirstName = "L", LastName = "jz" }; NameDto nameDto11 = Mapper.DynamicMap<NameDto>(name11); Console.WriteLine("11"); Console.WriteLine(nameDto11.FirstName + nameDto11.LastName); Console.WriteLine(); //Console.ReadKey(); //12.转换DataTable Mapper.Reset(); DataTable dt = new DataTable(); dt.Columns.Add("FirstName", typeof(string)); dt.Columns.Add("LastName", typeof(string)); dt.Rows.Add("L", "jz"); List<NameDto> nameDto12 = Mapper.DynamicMap<IDataReader, List<NameDto>>(dt.CreateDataReader()); Console.WriteLine("12"); Console.WriteLine(nameDto12[0].FirstName + nameDto12[0].LastName); Console.WriteLine(); //Console.ReadKey(); //emitMapper error //List<NameDto> nameDto20 = EmitMapper.ObjectMapperManager.DefaultInstance.GetMapper<IDataReader, List<NameDto>>().Map(dt.CreateDataReader()); //13.转化存在的对象 Mapper.Reset(); Mapper.CreateMap<Name, NameDto>() .ForMember(name => name.LastName, opt => opt.Ignore()); Name name13 = new Name() { FirstName = "L" }; NameDto nameDto13 = new NameDto() { LastName = "jz" }; Mapper.Map<Name, NameDto>(name13, nameDto13); //nameDto13 = Mapper.Map<Name, NameDto>(name13);//注意,必需使用上面的写法,不然nameDto13对象的LastName属性会被覆盖 Console.WriteLine("13"); Console.WriteLine(nameDto13.FirstName + nameDto13.LastName); Console.WriteLine(); //Console.ReadKey(); //14.Flatten特性 Store.Name.FirtName=FlattenName.NameFirstname Mapper.Reset(); Mapper.CreateMap<Store, FlattenName>(); Store store2 = new Store() { Name = new Name() { FirstName = "L", LastName = "jz" } }; FlattenName nameDto14 = Mapper.Map<Store, FlattenName>(store2); Console.WriteLine("14"); Console.WriteLine(nameDto14.NameFirstname + nameDto14.NameLastName); Console.WriteLine(); //Console.ReadKey(); //15.将Dictionary转化为对象,现在还不支持 Mapper.Reset(); Mapper.CreateMap<Dictionary<string, object>, Name>(); Dictionary<string, object> dict = new Dictionary<string, object>(); dict.Add("FirstName", "L"); //Name name15 = Mapper.DynamicMap<Dictionary<string, object>, Name>(dict); Name name15 = Mapper.Map<Dictionary<string, object>, Name>(dict); Console.WriteLine("15"); Console.WriteLine(name15.FirstName); Console.WriteLine(); Console.ReadKey(); } } public class Store { public Name Name { get; set; } public int Age { get; set; } } public class Name { public string FirstName { get; set; } public string LastName { get; set; } } public class StoreDto { public NameDto Name { get; set; } public int Age { get; set; } } public class NameDto { public string FirstName { get; set; } public string LastName { get; set; } public string AllName { get; set; } } public class FlattenName { public string NameFirstname { get; set; } public string NameLastName { get; set; } } public class NameConverter : TypeConverter<Name, NameDto> { protected override NameDto ConvertCore(Name source) { return new NameDto() { AllName = source.FirstName + source.LastName }; } } public class NameResolver : ValueResolver<Name, NameDto> { protected override NameDto ResolveCore(Name source) { return new NameDto() { FirstName = source.FirstName, LastName = source.LastName,AllName=source.FirstName+source.LastName }; } } public class NameFormatter : ValueFormatter<NameDto> { protected override string FormatValueCore(NameDto name) { return name.FirstName + name.LastName; } } public class StringFormatter : ValueFormatter<string> { protected override string FormatValueCore(string name) { return name + "-"; } } }
看云吧 kanyun8.com
