AutoMapper 9.0的改造（续）

Posted 2022-09-28 ncorecoder

tags:

篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了AutoMapper 9.0的改造（续）相关的知识，希望对你有一定的参考价值。

上一篇有一个读者，有疑问，如何自动化注册Dto

我开篇，做了一个自动化注册的

    public sealed class AutoInjectAttribute : Attribute
    
        public Type SourceType  get; 
        public Type TargetType  get; 

        public AutoInjectAttribute(Type sourceType, Type targetType)
        
            SourceType = sourceType;
            TargetType = targetType;

增加了一个特性，在Dto上面打上，参数1是源类型，参数2是Dto类型

增加一个工厂类保存自动转换的类型

    public class AutoInjectFactory
    
        public List<(Type,Type)> ConvertList  get;  = new List<(Type, Type)>();

        public void AddAssemblys(params Assembly[] assemblys)
        
            foreach (var assembly in assemblys)
            
                var atributes = assembly.GetTypes()
                    .Where(_type => _type.GetCustomAttribute<AutoInjectAttribute>() != null)
                    .Select(_type => _type.GetCustomAttribute<AutoInjectAttribute>());

                foreach (var atribute in atributes)
                
                    ConvertList.Add((atribute.SourceType, atribute.TargetType));

在原来的AddAutoMapper上找到修改的代码段

        public static IServiceCollection AddAutoMapper(this IServiceCollection service)
        
            ...略
            service.TryAddSingleton(serviceProvider =>
            
                var mapperConfigurationExpression = serviceProvider.GetRequiredService<MapperConfigurationExpression>();

                var instance = new MapperConfiguration(mapperConfigurationExpression);

                instance.AssertConfigurationIsValid();

                return instance;
            );
            ...略

            return service;

改为

        public static IServiceCollection AddAutoMapper(this IServiceCollection service)
        
            ...略
            service.TryAddSingleton(serviceProvider =>
            
                var mapperConfigurationExpression = serviceProvider.GetRequiredService<MapperConfigurationExpression>();
                var factory = serviceProvider.GetRequiredService<AutoInjectFactory>();

                foreach (var (sourceType,targetType) in factory.ConvertList)
                
                    mapperConfigurationExpression.CreateMap(sourceType, targetType);
                

                var instance = new MapperConfiguration(mapperConfigurationExpression);

                instance.AssertConfigurationIsValid();

                return instance;
            );
            ...略

            return service;

增加一组扩展方法

    public static class AutoMapperExtension
    
        ...略

        public static void UseAutoInject(this IApplicationBuilder applicationBuilder, params Assembly[] assemblys)
        
            var factory = applicationBuilder.ApplicationServices.GetRequiredService<AutoInjectFactory>();

            factory.AddAssemblys(assemblys);

在Startup.Configure方法内调用一下

看看测试

技术图片