Get新知识:
IPropertyMappingService PropertyMappingService 服务提供类 的提取接口。
代码语言：javascript复制 public interface IPropertyMappingService
{
Dictionary<string, PropertyMappingValue> GetPropertyMapping<TSource, TDestination>();
bool ValidMappingExixtsFor<TSource, TDestination>(string fields);
}IPropertyMapping PropertyMapping 类 的提取接口，便于使用，只需要调用接口，asp.net core会注入一个实例供于使用。
代码语言：javascript复制 public interface IPropertyMapping
{
}IPropertyCheckService PropertyCheckService 服务提供类 的提取接口
代码语言：javascript复制 public interface IPropertyCheckService
{
bool TypeHasProperities<T>(string fields);
}PropertyMappingValue 提供DTO的字段值的存放，以及排序方式，DestinationProperties 存放DTO类的全部字段值名。
代码语言：javascript复制 public class PropertyMappingValue
{
public IEnumerable<String> DestinationProperties { get; set; }
public bool Revert { get; set; }
public PropertyMappingValue(IEnumerable<string> destinationProperties, bool revert = false)
{
DestinationProperties = destinationProperties ?? throw new ArgumentNullException(nameof(destinationProperties));
Revert = revert;
}
}PropertyMapping 用于 实体类的字段 和 DTO类的字段 的映射关系的存放，即 MappingDictionary 属性， string 是实体类的字段值名，PropertyMappingValue 是 DTO类的字段值名。
代码语言：javascript复制 public class PropertyMapping<TSource, TDestination> : IPropertyMapping
{
public Dictionary<string, PropertyMappingValue> MappingDictionary { get;private set; }
public PropertyMapping(Dictionary<string, PropertyMappingValue> mappingDictionary)
{
MappingDictionary = mappingDictionary ?? throw new ArgumentNullException(nameof(mappingDictionary));
}
}PropertyMappingService 服务提供类，提供 获取属性映射关系的方法
代码语言：javascript复制 public class PropertyMappingService : IPropertyMappingService
{
// 只读字段，映射关系的配置，就是说明需要映射的两个类之间的字段对应关系
// 这里是 Company 和 CompanyDto 类之间的具体的字段对应关系的配置
private readonly Dictionary<string, PropertyMappingValue> _companyProperMapping =
new Dictionary<string, PropertyMappingValue>(StringComparer.OrdinalIgnoreCase)
{
{ "Id", new PropertyMappingValue(new List<String>{ "Id"})},
{ "Companyame", new PropertyMappingValue(new List<String>{ "Name"})},
{ "Country", new PropertyMappingValue(new List<String>{ "Country"})},
{ "Industry", new PropertyMappingValue(new List<String>{ "Industry"})},
{ "Product", new PropertyMappingValue(new List<String>{ "Product"})},
{ "Introduction", new PropertyMappingValue(new List<String>{ "Introduction"})}
};
// 这里是 Employee 和 EmployeeDto 类之间的具体的字段对应关系的配置
private readonly Dictionary<string, PropertyMappingValue> _employeeProperMapping =
new Dictionary<string, PropertyMappingValue>(StringComparer.OrdinalIgnoreCase)
{
{ "Id", new PropertyMappingValue(new List<String>{ "Id"})},
{ "CompanyId", new PropertyMappingValue(new List<String>{ "CompanyId"})},
{ "EmployeeNo", new PropertyMappingValue(new List<String>{ "EmployeeNo"})},
{ "Name", new PropertyMappingValue(new List<String>{ "First", "LastName"})},
{ "GenderDisplay", new PropertyMappingValue(new List<String>{ "Gender"})},
{ "Age", new PropertyMappingValue(new List<String>{ "DataOfBirth"}, true)}
};
// 存放PropertyMapping 的集合
private readonly IList<IPropertyMapping> _propertyMappings = new List<IPropertyMapping>();
// 构造函数，
public PropertyMappingService()
{
_propertyMappings.Add(new PropertyMapping<EmployeeDTO, Employee>(_employeeProperMapping));
_propertyMappings.Add(new PropertyMapping<CompanyDTO, Company>(_companyProperMapping));
}
public Dictionary<string, PropertyMappingValue> GetPropertyMapping<TSource, TDestination>()
{
// 从集合等序列中筛选 指定类型的元素，这里是筛选 PropertyMapping 泛型类型的元素
// 返回存放符合条件元素的集合
var matchingMapping = _propertyMappings.OfType<PropertyMapping<TSource, TDestination>>();
if (matchingMapping.Count() == 1)
{
return matchingMapping.First().MappingDictionary;
}
throw new Exception($"无法找到唯一的映射关系{typeof(TSource)}和{typeof(TDestination)}");
}
public bool ValidMappingExixtsFor<TSource, TDestination>(string fields)
{
if (string.IsNullOrWhiteSpace(fields))
{
return true;
}
var propertyMapping = GetPropertyMapping<TSource, TDestination>();
var fieldAfterSplit = fields.Split(',');
foreach (var field in fieldAfterSplit)
{
var trimmedFields = field.Trim();
var indexOfFirstSpace = trimmedFields.IndexOf(" ");
var propertyName = indexOfFirstSpace == -1 ? trimmedFields : trimmedFields.Remove(indexOfFirstSpace);
if (!propertyMapping.ContainsKey(propertyName))
{
return false;
}
}
return true;
}
}
