如何忽略 C# Automapper 中的 null 值

Question

I am using Automapper in C#.

Currently I am trying to map using below code.

CreateMap<Student, StudentDto>()
.ForMember(dest => dest.FeeType, opt =>
{
 opt.PreCondition(src => (src.Key == "Paid"));
 opt.MapFrom(src => src.Value);
});

I want to map only if the key == Paid else it should not map. However in this case, it is just passing null.

So lets say if the collection has 100 records and only 1 matches the condition other 99 records are passed as NULL.

Edit -- I am using Azure Function Apps and my Automapper version is 10.0.0

Please advise.

Answer 1

I think you have to update your ConfigureServices like=>

public void ConfigureServices(IServiceCollection services) {  
    // Auto Mapper Configurations  
    var mappingConfig = new MapperConfiguration(mc => {  
        mc.AddProfile(new MappingProfile());  
    });  
    IMapper mapper = mappingConfig.CreateMapper();  
    services.AddSingleton(mapper); 
    //This line should be updated
    services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1).AddJsonOptions(options => options.SerializerSettings.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore);  
}  

.AddJsonOptions(options => options.SerializerSettings.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore); of Newtonsoft.Json.NullValueHandling.Ignore , It will handle what you ask for.
Note: Please check the link of a documentation. I believe it will do the trick.
LINK