使用反射，我如何能得到所有类型的实现接口与c# 3.0/。NET 3.5用最少的代码，最小化迭代?
这是我想重写的内容:
foreach (Type t in this.GetType().Assembly.GetTypes())
if (t is IMyInterface)
; //do stuff
当前回答
其他答案在这里使用IsAssignableFrom。还可以使用System名称空间中的FindInterfaces，如本文所述。
下面是一个示例，检查当前正在执行的程序集文件夹中的所有程序集，查找实现某个接口的类(为了清晰起见，避免使用LINQ)。
static void Main() {
const string qualifiedInterfaceName = "Interfaces.IMyInterface";
var interfaceFilter = new TypeFilter(InterfaceFilter);
var path = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
var di = new DirectoryInfo(path);
foreach (var file in di.GetFiles("*.dll")) {
try {
var nextAssembly = Assembly.ReflectionOnlyLoadFrom(file.FullName);
foreach (var type in nextAssembly.GetTypes()) {
var myInterfaces = type.FindInterfaces(interfaceFilter, qualifiedInterfaceName);
if (myInterfaces.Length > 0) {
// This class implements the interface
}
}
} catch (BadImageFormatException) {
// Not a .net assembly - ignore
}
}
}
public static bool InterfaceFilter(Type typeObj, Object criteriaObj) {
return typeObj.ToString() == criteriaObj.ToString();
}
如果需要匹配多个接口，可以设置一个接口列表。
其他回答
(就性能而言)做你想做的事情并不容易。
反射主要使用程序集和类型，因此您必须获取程序集的所有类型并查询它们以获得正确的接口。这里有一个例子:
Assembly asm = Assembly.Load("MyAssembly");
Type[] types = asm.GetTypes();
Type[] result = types.where(x => x.GetInterface("IMyInterface") != null);
这将为您提供在程序集MyAssembly中实现IMyInterface的所有类型
其他答案在这里使用IsAssignableFrom。还可以使用System名称空间中的FindInterfaces，如本文所述。
下面是一个示例，检查当前正在执行的程序集文件夹中的所有程序集，查找实现某个接口的类(为了清晰起见，避免使用LINQ)。
static void Main() {
const string qualifiedInterfaceName = "Interfaces.IMyInterface";
var interfaceFilter = new TypeFilter(InterfaceFilter);
var path = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
var di = new DirectoryInfo(path);
foreach (var file in di.GetFiles("*.dll")) {
try {
var nextAssembly = Assembly.ReflectionOnlyLoadFrom(file.FullName);
foreach (var type in nextAssembly.GetTypes()) {
var myInterfaces = type.FindInterfaces(interfaceFilter, qualifiedInterfaceName);
if (myInterfaces.Length > 0) {
// This class implements the interface
}
}
} catch (BadImageFormatException) {
// Not a .net assembly - ignore
}
}
}
public static bool InterfaceFilter(Type typeObj, Object criteriaObj) {
return typeObj.ToString() == criteriaObj.ToString();
}
如果需要匹配多个接口，可以设置一个接口列表。
其他答案是没有使用通用接口。
这一个做到了，只是用typeof(T)替换typeof(ISomeInterface)。
List<string> types = AppDomain.CurrentDomain.GetAssemblies().SelectMany(x => x.GetTypes())
.Where(x => typeof(ISomeInterface).IsAssignableFrom(x) && !x.IsInterface && !x.IsAbstract)
.Select(x => x.Name).ToList();
所以,
AppDomain.CurrentDomain.GetAssemblies().SelectMany(x => x.GetTypes())
我们得到了所有的集合
!x.IsInterface && !x.IsAbstract
是用来排除接口和抽象的和
.Select(x => x.Name).ToList();
把它们列在一个列表里。
编辑:我刚刚看到了编辑，澄清了最初的问题是为了减少迭代/代码，这作为一个练习是很好的，但在实际情况下，你会想要最快的实现，不管底层LINQ看起来有多酷。
下面是我的Utils方法，用于遍历加载的类型。它处理常规类和接口，如果您正在自己的/第三方代码库中寻找实现，那么excludeSystemTypes选项将极大地加快速度。
public static List<Type> GetSubclassesOf(this Type type, bool excludeSystemTypes) {
List<Type> list = new List<Type>();
IEnumerator enumerator = Thread.GetDomain().GetAssemblies().GetEnumerator();
while (enumerator.MoveNext()) {
try {
Type[] types = ((Assembly) enumerator.Current).GetTypes();
if (!excludeSystemTypes || (excludeSystemTypes && !((Assembly) enumerator.Current).FullName.StartsWith("System."))) {
IEnumerator enumerator2 = types.GetEnumerator();
while (enumerator2.MoveNext()) {
Type current = (Type) enumerator2.Current;
if (type.IsInterface) {
if (current.GetInterface(type.FullName) != null) {
list.Add(current);
}
} else if (current.IsSubclassOf(type)) {
list.Add(current);
}
}
}
} catch {
}
}
return list;
}
我承认，这并不漂亮。
已经有许多有效的答案，但我想添加另一个实现作为类型扩展和一个单元测试列表，以演示不同的场景:
public static class TypeExtensions
{
public static IEnumerable<Type> GetAllTypes(this Type type)
{
var typeInfo = type.GetTypeInfo();
var allTypes = GetAllImplementedTypes(type).Concat(typeInfo.ImplementedInterfaces);
return allTypes;
}
private static IEnumerable<Type> GetAllImplementedTypes(Type type)
{
yield return type;
var typeInfo = type.GetTypeInfo();
var baseType = typeInfo.BaseType;
if (baseType != null)
{
foreach (var foundType in GetAllImplementedTypes(baseType))
{
yield return foundType;
}
}
}
}
该算法支持以下场景:
public static class GetAllTypesTests
{
public class Given_A_Sample_Standalone_Class_Type_When_Getting_All_Types
: Given_When_Then_Test
{
private Type _sut;
private IEnumerable<Type> _expectedTypes;
private IEnumerable<Type> _result;
protected override void Given()
{
_sut = typeof(SampleStandalone);
_expectedTypes =
new List<Type>
{
typeof(SampleStandalone),
typeof(object)
};
}
protected override void When()
{
_result = _sut.GetAllTypes();
}
[Fact]
public void Then_It_Should_Return_The_Right_Type()
{
_result.Should().BeEquivalentTo(_expectedTypes);
}
}
public class Given_A_Sample_Abstract_Base_Class_Type_When_Getting_All_Types
: Given_When_Then_Test
{
private Type _sut;
private IEnumerable<Type> _expectedTypes;
private IEnumerable<Type> _result;
protected override void Given()
{
_sut = typeof(SampleBase);
_expectedTypes =
new List<Type>
{
typeof(SampleBase),
typeof(object)
};
}
protected override void When()
{
_result = _sut.GetAllTypes();
}
[Fact]
public void Then_It_Should_Return_The_Right_Type()
{
_result.Should().BeEquivalentTo(_expectedTypes);
}
}
public class Given_A_Sample_Child_Class_Type_When_Getting_All_Types
: Given_When_Then_Test
{
private Type _sut;
private IEnumerable<Type> _expectedTypes;
private IEnumerable<Type> _result;
protected override void Given()
{
_sut = typeof(SampleChild);
_expectedTypes =
new List<Type>
{
typeof(SampleChild),
typeof(SampleBase),
typeof(object)
};
}
protected override void When()
{
_result = _sut.GetAllTypes();
}
[Fact]
public void Then_It_Should_Return_The_Right_Type()
{
_result.Should().BeEquivalentTo(_expectedTypes);
}
}
public class Given_A_Sample_Base_Interface_Type_When_Getting_All_Types
: Given_When_Then_Test
{
private Type _sut;
private IEnumerable<Type> _expectedTypes;
private IEnumerable<Type> _result;
protected override void Given()
{
_sut = typeof(ISampleBase);
_expectedTypes =
new List<Type>
{
typeof(ISampleBase)
};
}
protected override void When()
{
_result = _sut.GetAllTypes();
}
[Fact]
public void Then_It_Should_Return_The_Right_Type()
{
_result.Should().BeEquivalentTo(_expectedTypes);
}
}
public class Given_A_Sample_Child_Interface_Type_When_Getting_All_Types
: Given_When_Then_Test
{
private Type _sut;
private IEnumerable<Type> _expectedTypes;
private IEnumerable<Type> _result;
protected override void Given()
{
_sut = typeof(ISampleChild);
_expectedTypes =
new List<Type>
{
typeof(ISampleBase),
typeof(ISampleChild)
};
}
protected override void When()
{
_result = _sut.GetAllTypes();
}
[Fact]
public void Then_It_Should_Return_The_Right_Type()
{
_result.Should().BeEquivalentTo(_expectedTypes);
}
}
public class Given_A_Sample_Implementation_Class_Type_When_Getting_All_Types
: Given_When_Then_Test
{
private Type _sut;
private IEnumerable<Type> _expectedTypes;
private IEnumerable<Type> _result;
protected override void Given()
{
_sut = typeof(SampleImplementation);
_expectedTypes =
new List<Type>
{
typeof(SampleImplementation),
typeof(SampleChild),
typeof(SampleBase),
typeof(ISampleChild),
typeof(ISampleBase),
typeof(object)
};
}
protected override void When()
{
_result = _sut.GetAllTypes();
}
[Fact]
public void Then_It_Should_Return_The_Right_Type()
{
_result.Should().BeEquivalentTo(_expectedTypes);
}
}
public class Given_A_Sample_Interface_Instance_Type_When_Getting_All_Types
: Given_When_Then_Test
{
private Type _sut;
private IEnumerable<Type> _expectedTypes;
private IEnumerable<Type> _result;
class Foo : ISampleChild { }
protected override void Given()
{
var foo = new Foo();
_sut = foo.GetType();
_expectedTypes =
new List<Type>
{
typeof(Foo),
typeof(ISampleChild),
typeof(ISampleBase),
typeof(object)
};
}
protected override void When()
{
_result = _sut.GetAllTypes();
}
[Fact]
public void Then_It_Should_Return_The_Right_Type()
{
_result.Should().BeEquivalentTo(_expectedTypes);
}
}
sealed class SampleStandalone { }
abstract class SampleBase { }
class SampleChild : SampleBase { }
interface ISampleBase { }
interface ISampleChild : ISampleBase { }
class SampleImplementation : SampleChild, ISampleChild { }
}
