Automapper 在映射 1400 条记录时运行速度极慢

Automapper 在映射 1400 条记录时运行速度极慢

csharp
public class Student
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
    // 其他属性...
}
public class StudentDTO
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
    // 其他属性...
}

csharp
var config = new MapperConfiguration(cfg => cfg.CreateMap());
var mapper = config.CreateMapper();
var students = GetStudentsFromDatabase(); // 从数据库获取学生记录
var studentDTOs = mapper.Map>(students);

csharp
var config = new MapperConfiguration(cfg =>
{
    var studentMapExpression = CreateMapExpression();
    cfg.CreateMap().ConvertUsing(studentMapExpression);
});
var mapper = config.CreateMapper();
var students = GetStudentsFromDatabase(); // 从数据库获取学生记录
var studentDTOs = mapper.Map>(students);

csharp
public static Expression> CreateMapExpression()
{
    var sourceProperties = typeof(TSource).GetProperties();
    var destinationProperties = typeof(TDestination).GetProperties();
    var sourceParameter = Expression.Parameter(typeof(TSource), "source");
    var bindings = destinationProperties
        .Select(destProp =>
        {
            var sourceProp = sourceProperties.FirstOrDefault(srcProp => srcProp.Name == destProp.Name);
            if (sourceProp != null && sourceProp.PropertyType == destProp.PropertyType)
            {
                return Expression.Bind(destProp, Expression.Property(sourceParameter, sourceProp));
            }
            return null;
        })
        .Where(binding => binding != null);
    var memberInit = Expression.MemberInit(Expression.New(typeof(TDestination)), bindings);
    return Expression.Lambda>(memberInit, sourceParameter);
}