C# 基于参数类型调用函数
我试图找出如何简化以下内容 假设我有两个实体类C# 基于参数类型调用函数,c#,.net,list,generics,interface,C#,.net,List,Generics,Interface,我试图找出如何简化以下内容 假设我有两个实体类 public class A { public int Id { get; set; } public string Name { get; set; } public string City { get; set; } } 及 相似但不相同的类 每个类都有一个用于CRUD操作的存储库类,例如 public class RepA { public static List<A> GetAll()
public class A
{
public int Id { get; set; }
public string Name { get; set; }
public string City { get; set; }
}
及
相似但不相同的类
每个类都有一个用于CRUD操作的存储库类,例如
public class RepA
{
public static List<A> GetAll()
{
List<A> list = new List<A>();
A a1 = new A() {Id=1, Name="First A", City="Boston"};
A a2 = new A() {Id=2, Name="First B", City="Chicago"};
A a3 = new A() {Id=3, Name="First C", City="San Francisco"};
list.Add(a1);
list.Add(a2);
list.Add(a3);
return list;
}
public static void SaveAll(List<A> list)
{
foreach (A a in list)
{
Console.WriteLine("Saved Id = {0} Name = {1} City={2}",
a.Id, a.Name, a.City);
}
}
}
创建
基类
或使用:
公共接口IBase
{
List GetAll();
void SaveAll(列表项);
}
公共类RepA:IBase
{
公共列表GetAll(){返回新列表();}
公共void SaveAll(列表repA){}
}
公共类代表:IBase
{
公共列表GetAll(){返回新列表();}
公共void SaveAll(列表repB){}
}
void Main()
{
IBase chosenType=随机chosenType();
var list=chosenType.GetAll();
}
您可以让存储库实现一个接口,比如说IGetAllSaveAll
。然后,您可以将存储库存储在列表中,并将它们转换到该接口。这样,您就可以对所有这些对象调用GetAll
函数:
(实际上,第一个接口不是必需的,您可以直接将其编写为IEnumerable GetAll()
…)
然后,您可以在某个地方保存所有这些存储库的词汇:
Dictionnary<Type, IGetAllSaveAll> myDic;
然后称之为:
Type t = RandomChosenType();
myDic[t].GetAll();
基于反射和对类结构的一些假设,尝试这种方法:
static void Main(string[] args)
{
var types = Assembly.GetExecutingAssembly().Modules
.SelectMany(m => m.GetTypes())
.Where(t =>
t.GetMethod("GetAll") != null &&
t.GetMethod("SaveAll") != null &&
t.GetMethod("GetAll").ReturnType.IsGenericType)
.Select(t =>
new
{
RepositoryType = t,
ReturnTypeArgument =
t.GetMethod("GetAll").ReturnType.GenericTypeArguments[0]
}
)
.ToList();
(new List<dynamic> { new A(), new B() }).ToList().ForEach(chosenType =>
{
var association = types
.FirstOrDefault(t =>
t.ReturnTypeArgument == chosenType.GetType());
if (association == null)
return;
var repType = association.RepositoryType;
dynamic list = repType.GetMethod("GetAll")
.Invoke(chosenType, new object[] { });
repType.GetMethod("SaveAll")
.Invoke(chosenType, new object[] { list });
});
}
static void Main(字符串[]args)
{
var types=Assembly.getExecutionGassembly().Modules
.SelectMany(m=>m.GetTypes())
.其中(t=>
t、 GetMethod(“GetAll”)!=null&&
t、 GetMethod(“SaveAll”)!=null&&
t、 GetMethod(“GetAll”).ReturnType.IsGenericType)
.选择(t=>
新的
{
RepositoryType=t,
ReturnTypeArgument=
t、 GetMethod(“GetAll”).ReturnType.GenericTypeArguments[0]
}
)
.ToList();
(新列表{new A(),new B()}).ToList().ForEach(chosenType=>
{
变量关联=类型
.FirstOrDefault(t=>
t、 ReturnTypeArgument==chosenType.GetType());
if(关联==null)
返回;
var repType=association.RepositoryType;
动态列表=repType.GetMethod(“GetAll”)
.Invoke(chosenType,新对象[]{});
repType.GetMethod(“SaveAll”)
.Invoke(chosenType,新对象[]{list});
});
}
您发布的代码使用静态方法。为了实现接口,您将需要实例方法。除非您想使用反射(我认为应该避免),否则这些方法需要不知道类型。大概是这样的:
public interface IRepository {
IEnumerable<object> GetAll();
}
公共接口IRepository{
IEnumerable GetAll();
}
在RepA中:
IEnumerable<object> IRepository.GetAll() {
return RepA.GetAll();
}
IEnumerable IRepository.GetAll(){
返回RepA.GetAll();
}
您的每个菜单选项都可以在类型为
IRepository
的字段中包含相应存储库类的实例,而不是存储类型。对其中一个实例调用GetAll
后,如果需要,您可以稍后将结果强制转换为特定类型(如List
)。您应该使用一个通用存储库。这些操作应由代理处理。存储库可以如下所示:
public class GenericRepositoryExample
{
public void Save<T>(IList<T> persons, SaveDelegate<T> save)
{
foreach (T person in persons)
{
Console.WriteLine(save(person));
}
}
}
为了说明此设置的使用,我创建了以下单元测试:
[Test]
public void TestGenericRepository()
{
IList<A> aList = new List<A>();
aList.Add(new A() { Id = 1, name = "George", city = "Chicago"});
aList.Add(new A() { Id = 2, name = "Bill", city = "Toledo" });
List<B> bList = new List<B>();
bList.Add(new B() {Id= 1, Nom = "Nathalie", ville = "Paris"});
bList.Add(new B() {Id = 2, Nom = "Michelle", ville = "Lyon"});
GenericRepositoryExample repository = new GenericRepositoryExample();
repository.Save<A>(aList,HelperClass.EnglishSave);
repository.Save<B>(bList,HelperClass.FrenchSave);
}
[测试]
public void TestGenericRepository()
{
IList aList=新列表();
Add(新的A(){Id=1,name=“George”,city=“Chicago”});
Add(新的A(){Id=2,name=“Bill”,city=“Toledo”});
List bList=新列表();
添加(新的B(){Id=1,Nom=“Nathalie”,ville=“Paris”});
添加(新的B(){Id=2,Nom=“Michelle”,ville=“Lyon”});
GenericRepositoryExample repository=新的GenericRepositoryExample();
Save(aList,HelperClass.EnglishSave);
Save(bList,HelperClass.FrenchSave);
}
给定您的确切场景,其中您有一个代表每种可能的数据类型的枚举,下面是一些可能有效的方法
使用属性将每个枚举值映射到存储库类型。每个存储库继承自一个泛型类,该类实现一个非强类型的基本接口。repo方法从静态成员变为实例成员。基本repo类必须进行强制转换才能将对象
转换为适当的类型并返回,但实际的存储库实现是强类型的
您可以更进一步,尝试使用表达式树缓存一些反射,这样您只需执行一次,但这取决于您真正需要优化的程度
public enum ChosenType {
[Repo(typeof(RepA))] A = 0,
[Repo(typeof(RepB))] B = 1
}
public class RepoAttribute : Attribute {
public RepoAttribute(Type repoType) { RepoType = repoType; }
public Type RepoType { get; set; }
}
class Program
{
static void Main()
{
ChosenType chosentype = RandomChosenType(); //A or B
// Make an instance of the appropriate repo based on the mapping
// to the enum value.
// This is a moderately expensive call, and there's room for improvement
// by using expression trees and caching lambda expressions.
var repo = (IRepo)Activator.CreateInstance(
((RepoAttribute)typeof(ChosenType).GetMember(chosentype.ToString())
.Single().GetCustomAttributes(typeof(RepoAttribute), false).Single()
).RepoType);
var list = repo.GetAll();
repo.SaveAll(list);
Console.Read();
}
static Random _rand = new Random();
static ChosenType RandomChosenType()
{
return (ChosenType)_rand.Next(0, 2);
}
}
public class A { /* No change */ }
public class B { /* No change */ }
public interface IRepo {
List<object> GetAll();
void SaveAll(List<object> list);
}
public abstract class Repo<T> : IRepo {
List<object> IRepo.GetAll() {
return GetAll().Cast<object>().ToList();
}
void IRepo.SaveAll(List<object> list) {
SaveAll(list.Cast<T>().ToList());
}
public abstract List<T> GetAll();
public abstract void SaveAll(List<T> list);
}
public class RepA : Repo<A> {
public override List<A> GetAll() { /* No change except the signature */ }
public override void SaveAll(List<A> list) { /* No change except the signature */ }
}
public class RepB : Repo<B> {
public override List<B> GetAll() { /* No change except the signature */ }
public override void SaveAll(List<B> list) { /* No change except the signature */ }
}
public enum ChosenType{
[Repo(typeof(RepA))]A=0,
[Repo(typeof(RepB))]B=1
}
公共类属性:属性{
公共repotAttribute(类型repoType){repoType=repoType;}
公共类型RepoType{get;set;}
}
班级计划
{
静态void Main()
{
ChosenType ChosenType=RandomChosenType();//A或B
//根据映射创建相应的repo实例
//添加到枚举值。
//这是一个中等昂贵的电话,还有改进的余地
//通过使用表达式树和缓存lambda表达式。
var repo=(IRepo)Activator.CreateInstance(
((RepoAttribute)typeof(ChosenType).GetMember(ChosenType.ToString())
.Single().GetCustomAttributes(typeof(RepoAttribute),false).Single()
)(1),;
var list=repo.GetAll();
回购保存全部(列表);
Console.Read();
}
静态随机_rand=新随机();
静态ChosenType随机ChosenType()
{
返回值(ChosenType)_rand.Next(0,2);
}
}
公共A类{/*无变化*/}
公共类B{/*无变化*/}
公共接口IRepo{
List GetAll();
void SaveAll(列表);
}
公共抽象类Repo:IRepo{
利斯
myDic.Add(typeof(A), new RepA());
Type t = RandomChosenType();
myDic[t].GetAll();
static void Main(string[] args)
{
var types = Assembly.GetExecutingAssembly().Modules
.SelectMany(m => m.GetTypes())
.Where(t =>
t.GetMethod("GetAll") != null &&
t.GetMethod("SaveAll") != null &&
t.GetMethod("GetAll").ReturnType.IsGenericType)
.Select(t =>
new
{
RepositoryType = t,
ReturnTypeArgument =
t.GetMethod("GetAll").ReturnType.GenericTypeArguments[0]
}
)
.ToList();
(new List<dynamic> { new A(), new B() }).ToList().ForEach(chosenType =>
{
var association = types
.FirstOrDefault(t =>
t.ReturnTypeArgument == chosenType.GetType());
if (association == null)
return;
var repType = association.RepositoryType;
dynamic list = repType.GetMethod("GetAll")
.Invoke(chosenType, new object[] { });
repType.GetMethod("SaveAll")
.Invoke(chosenType, new object[] { list });
});
}
public interface IRepository {
IEnumerable<object> GetAll();
}
IEnumerable<object> IRepository.GetAll() {
return RepA.GetAll();
}
public class GenericRepositoryExample
{
public void Save<T>(IList<T> persons, SaveDelegate<T> save)
{
foreach (T person in persons)
{
Console.WriteLine(save(person));
}
}
}
public delegate string SaveDelegate<T>(T input);
public static class HelperClass
{
public static string FrenchSave(B frenchInput)
{
string result = string.Format("ID = {0}; Name = {1}; City = {2}", frenchInput.Id, frenchInput.Nom, frenchInput.ville);
return result;
}
public static string EnglishSave(A englishInput)
{
string result = string.Format("ID = {0}; Name = {1}; City = {2}", englishInput.Id, englishInput.name, englishInput.city);
return result;
}
}
[Test]
public void TestGenericRepository()
{
IList<A> aList = new List<A>();
aList.Add(new A() { Id = 1, name = "George", city = "Chicago"});
aList.Add(new A() { Id = 2, name = "Bill", city = "Toledo" });
List<B> bList = new List<B>();
bList.Add(new B() {Id= 1, Nom = "Nathalie", ville = "Paris"});
bList.Add(new B() {Id = 2, Nom = "Michelle", ville = "Lyon"});
GenericRepositoryExample repository = new GenericRepositoryExample();
repository.Save<A>(aList,HelperClass.EnglishSave);
repository.Save<B>(bList,HelperClass.FrenchSave);
}
public enum ChosenType {
[Repo(typeof(RepA))] A = 0,
[Repo(typeof(RepB))] B = 1
}
public class RepoAttribute : Attribute {
public RepoAttribute(Type repoType) { RepoType = repoType; }
public Type RepoType { get; set; }
}
class Program
{
static void Main()
{
ChosenType chosentype = RandomChosenType(); //A or B
// Make an instance of the appropriate repo based on the mapping
// to the enum value.
// This is a moderately expensive call, and there's room for improvement
// by using expression trees and caching lambda expressions.
var repo = (IRepo)Activator.CreateInstance(
((RepoAttribute)typeof(ChosenType).GetMember(chosentype.ToString())
.Single().GetCustomAttributes(typeof(RepoAttribute), false).Single()
).RepoType);
var list = repo.GetAll();
repo.SaveAll(list);
Console.Read();
}
static Random _rand = new Random();
static ChosenType RandomChosenType()
{
return (ChosenType)_rand.Next(0, 2);
}
}
public class A { /* No change */ }
public class B { /* No change */ }
public interface IRepo {
List<object> GetAll();
void SaveAll(List<object> list);
}
public abstract class Repo<T> : IRepo {
List<object> IRepo.GetAll() {
return GetAll().Cast<object>().ToList();
}
void IRepo.SaveAll(List<object> list) {
SaveAll(list.Cast<T>().ToList());
}
public abstract List<T> GetAll();
public abstract void SaveAll(List<T> list);
}
public class RepA : Repo<A> {
public override List<A> GetAll() { /* No change except the signature */ }
public override void SaveAll(List<A> list) { /* No change except the signature */ }
}
public class RepB : Repo<B> {
public override List<B> GetAll() { /* No change except the signature */ }
public override void SaveAll(List<B> list) { /* No change except the signature */ }
}