参考资料:C#中Dictionary的用法
实例:建立字典服务,字典为string-->List
1、建立一个类,继承List
public class PropertyMappingValue
{
public IEnumerable<string> DestinationProperties { get; private set; }
public PropertyMappingValue(IEnumerable<string> destinationProperties)
{
DestinationProperties = destinationProperties;
}
}
2、建立一个接口类PropertyMapping<TSource, TDestination>作为映射类,其表达从TSource到TDestination的映射,该映射包含一个字典规则Dictionary<string, PropertyMappingValue>,并在构造函数中用一个字典规则初始化该映射
public interface IPropertyMapping
{
}
public class PropertyMapping<TSource, TDestination> : IPropertyMapping
{
public Dictionary<string, PropertyMappingValue> _mappingDictionary { get; set; }
public PropertyMapping(Dictionary<string, PropertyMappingValue> mappingDictionary)
{
_mappingDictionary = mappingDictionary;
}
}
3、建一个接口类(本例中将字典的初始化与服务初始化放到了一起,也可以分开)
public interface IPropertyMappingService
{
Dictionary<string, PropertyMappingValue> GetPropertyMapping<TSource, TDestination>();
bool IsMappingExists<TSource, TDestination>(string fields);
bool IsPropertiesExists<T>(string fields);
}
public class PropertyMappingService : IPropertyMappingService
{
private Dictionary<string, PropertyMappingValue> _touristRoutePropertyMapping = new Dictionary<string, PropertyMappingValue>(StringComparer.OrdinalIgnoreCase)
{
{ "Id", new PropertyMappingValue(new List<string>(){ "Id" }) },
{ "Title", new PropertyMappingValue(new List<string>(){ "Title" })},
{ "Rating", new PropertyMappingValue(new List<string>(){ "Rating" })},
{ "OriginalPrice", new PropertyMappingValue(new List<string>(){ "OriginalPrice" })},
};
private IList<IPropertyMapping> _propertyMappings = new List<IPropertyMapping>();
public PropertyMappingService()
{
_propertyMappings.Add( new PropertyMapping<TouristRouteDto, TouristRoute>(_touristRoutePropertyMapping));
}
public Dictionary<string, PropertyMappingValue>
GetPropertyMapping<TSource, TDestination>()
{
// 获得匹配的映射对象
var matchingMapping =
_propertyMappings.OfType<PropertyMapping<TSource, TDestination>>();//根据类型参数从IEnumerable集合中筛选出对应的元素
if (matchingMapping.Count() == 1)
{
return matchingMapping.First()._mappingDictionary;
}
throw new Exception(
$"Cannot find exact property mapping instance for <{typeof(TSource)},{typeof(TDestination)}");
}
public bool IsMappingExists<TSource, TDestination>(string fields)
{
var propertyMapping = GetPropertyMapping<TSource, TDestination>();
if (string.IsNullOrWhiteSpace(fields))
{
return true;
}
//逗号来分隔字段字符串
var fieldsAfterSplit = fields.Split(",");
foreach (var field in fieldsAfterSplit)
{
// 去掉空格
var trimmedField = field.Trim();
// 获得属性名称字符串
var indexOfFirstSpace = trimmedField.IndexOf(" ");
var propertyName = indexOfFirstSpace == -1 ? trimmedField : trimmedField.Remove(indexOfFirstSpace);
if (!propertyMapping.ContainsKey(propertyName))
{
return false;
}
}
return true;
}
public bool IsPropertiesExists<T>(string fields)
{
if (string.IsNullOrWhiteSpace(fields))
{
return true;
}
//逗号来分隔字段字符串
var fieldsAfterSplit = fields.Split(',');
foreach(var field in fieldsAfterSplit)
{
// 获得属性名称字符串
var propertyName = field.Trim();
var propertyInfo = typeof(T).GetProperty( propertyName, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance
);
// 如果T中没找到对应的属性
if(propertyInfo == null)
{
return false;
}
}
return true;
}
}
如果将初始化做成构造函数,如下:
public class PropertyMappingService : IPropertyMappingService
{
private IList<IPropertyMapping> _propertyMappings = new List<IPropertyMapping>();
public PropertyMappingService(params IPropertyMapping[] propertyMapping)
{
foreach(var property in propertyMapping)
_propertyMappings.Add(property);
}
- 注入服务
services.AddTransient<IPropertyMappingService, PropertyMappingService>();