Type.FindInterfaces(TypeFilter, Object) Method
Definition
Important
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public:
virtual cli::array <Type ^> ^ FindInterfaces(System::Reflection::TypeFilter ^ filter, System::Object ^ filterCriteria);public virtual Type[] FindInterfaces (System.Reflection.TypeFilter filter, object? filterCriteria);public virtual Type[] FindInterfaces (System.Reflection.TypeFilter filter, object filterCriteria);abstract member FindInterfaces : System.Reflection.TypeFilter * obj -> Type[]
override this.FindInterfaces : System.Reflection.TypeFilter * obj -> Type[]Public Overridable Function FindInterfaces (filter As TypeFilter, filterCriteria As Object) As Type()Parameters
- filter
- TypeFilter
The delegate that compares the interfaces against filterCriteria.
- filterCriteria
- Object
The search criteria that determines whether an interface should be included in the returned array.
Returns
An array of Type objects representing a filtered list of the interfaces implemented or inherited by the current Type, or an empty array if no interfaces matching the filter are implemented or inherited by the current Type.
Implements
Exceptions
filter is null.
A static initializer is invoked and throws an exception.
Examples
The following example finds the specified interface implemented or inherited by the specified type, and then displays the interface names.
#using <system.xml.dll>
using namespace System;
using namespace System::Xml;
using namespace System::Reflection;
public ref class MyFindInterfacesSample
{
public:
static bool MyInterfaceFilter(Type^ typeObj, Object^ criteriaObj)
{
if(typeObj->ToString()->Equals(criteriaObj->ToString()))
return true;
else
return false;
}
};
int main()
{
try
{
XmlDocument^ myXMLDoc = gcnew XmlDocument;
myXMLDoc->LoadXml("<book genre='novel' ISBN='1-861001-57-5'>"
+ "<title>Pride And Prejudice</title> </book>");
Type^ myType = myXMLDoc->GetType();
// Specify the TypeFilter delegate that compares the interfaces
// against filter criteria.
TypeFilter^ myFilter = gcnew TypeFilter(
MyFindInterfacesSample::MyInterfaceFilter);
array<String^>^myInterfaceList = {"System.Collections.IEnumerable",
"System.Collections.ICollection"};
for(int index = 0; index < myInterfaceList->Length; index++)
{
array<Type^>^myInterfaces = myType->FindInterfaces(
myFilter, myInterfaceList[index]);
if(myInterfaces->Length > 0)
{
Console::WriteLine("\n{0} implements the interface {1}.",
myType, myInterfaceList[index]);
for(int j = 0; j < myInterfaces->Length; j++)
Console::WriteLine("Interfaces supported: {0}.",
myInterfaces[j]);
}
else
Console::WriteLine(
"\n{0} does not implement the interface {1}.",
myType, myInterfaceList[index]);
}
}
catch(ArgumentNullException^ e)
{
Console::WriteLine("ArgumentNullException: {0}", e->Message);
}
catch(TargetInvocationException^ e)
{
Console::WriteLine("TargetInvocationException: {0}", e->Message);
}
catch(Exception^ e)
{
Console::WriteLine("Exception: {0}", e->Message);
}
}
using System;
using System.Xml;
using System.Reflection;
public class MyFindInterfacesSample
{
public static void Main()
{
try
{
XmlDocument myXMLDoc = new XmlDocument();
myXMLDoc.LoadXml("<book genre='novel' ISBN='1-861001-57-5'>" +
"<title>Pride And Prejudice</title>" + "</book>");
Type myType = myXMLDoc.GetType();
// Specify the TypeFilter delegate that compares the
// interfaces against filter criteria.
TypeFilter myFilter = new TypeFilter(MyInterfaceFilter);
String[] myInterfaceList = new String[2]
{"System.Collections.IEnumerable",
"System.Collections.ICollection"};
for(int index=0; index < myInterfaceList.Length; index++)
{
Type[] myInterfaces = myType.FindInterfaces(myFilter,
myInterfaceList[index]);
if (myInterfaces.Length > 0)
{
Console.WriteLine("\n{0} implements the interface {1}.",
myType, myInterfaceList[index]);
for(int j =0;j < myInterfaces.Length;j++)
Console.WriteLine("Interfaces supported: {0}.",
myInterfaces[j].ToString());
}
else
Console.WriteLine(
"\n{0} does not implement the interface {1}.",
myType,myInterfaceList[index]);
}
}
catch(ArgumentNullException e)
{
Console.WriteLine("ArgumentNullException: " + e.Message);
}
catch(TargetInvocationException e)
{
Console.WriteLine("TargetInvocationException: " + e.Message);
}
catch(Exception e)
{
Console.WriteLine("Exception: " + e.Message);
}
}
public static bool MyInterfaceFilter(Type typeObj,Object criteriaObj)
{
if(typeObj.ToString() == criteriaObj.ToString())
return true;
else
return false;
}
}
open System
open System.Xml
open System.Reflection
let myInterfaceFilter (typeObj: Type) (criteriaObj: obj) =
string typeObj = string criteriaObj
try
let myXMLDoc = XmlDocument()
myXMLDoc.LoadXml("<book genre='novel' ISBN='1-861001-57-5'>" + "<title>Pride And Prejudice</title>" + "</book>")
let myType = myXMLDoc.GetType()
// Specify the TypeFilter delegate that compares the
// interfaces against filter criteria.
let myFilter = TypeFilter myInterfaceFilter
let myInterfaceList =
[ "System.Collections.IEnumerable"
"System.Collections.ICollection" ]
for i in myInterfaceList do
let myInterfaces = myType.FindInterfaces(myFilter, i)
if myInterfaces.Length > 0 then
printfn $"\n{myType} implements the interface {i}."
for j in myInterfaces do
printfn $"Interfaces supported: {j}."
else
printfn $"\n{myType} does not implement the interface {i}."
with
| :? ArgumentNullException as e ->
printfn $"ArgumentNullException: {e.Message}"
| :? TargetInvocationException as e ->
printfn $"TargetInvocationException: {e.Message}"
| e ->
printfn $"Exception: {e.Message}"
Imports System.Xml
Imports System.Reflection
Public Class MyFindInterfacesSample
Public Shared Sub Main()
Try
Dim myXMLDoc As New XmlDocument()
myXMLDoc.LoadXml("<book genre='novel' ISBN='1-861001-57-5'>" _
& "<title>Pride And Prejudice</title>" & "</book>")
Dim myType As Type = myXMLDoc.GetType()
' Specify the TypeFilter delegate that compares the
' interfaces against filter criteria.
Dim myFilter As New TypeFilter(AddressOf MyInterfaceFilter)
Dim myInterfaceList() As String = _
{"System.Collections.IEnumerable", _
"System.Collections.ICollection"}
Dim index As Integer
For index = 0 To myInterfaceList.Length - 1
Dim myInterfaces As Type() = _
myType.FindInterfaces(myFilter, myInterfaceList(index))
If myInterfaces.Length > 0 Then
Console.WriteLine(ControlChars.Cr & _
"{0} implements the interface {1}.", _
myType, myInterfaceList(index))
Dim j As Integer
For j = 0 To myInterfaces.Length - 1
Console.WriteLine("Interfaces supported: {0}", _
myInterfaces(j).ToString())
Next j
Else
Console.WriteLine(ControlChars.Cr & _
"{0} does not implement the interface {1}.", _
myType, myInterfaceList(index))
End If
Next index
Catch e As ArgumentNullException
Console.WriteLine("ArgumentNullException: " & e.Message)
Catch e As TargetInvocationException
Console.WriteLine("TargetInvocationException: " & e.Message)
Catch e As Exception
Console.WriteLine("Exception: " & e.Message)
End Try
End Sub
Public Shared Function MyInterfaceFilter(ByVal typeObj As Type, _
ByVal criteriaObj As [Object]) As Boolean
If typeObj.ToString() = criteriaObj.ToString() Then
Return True
Else
Return False
End If
End Function 'MyInterfaceFilter
End Class
Remarks
This method can be overridden by a derived class.
The Module.FilterTypeName and Module.FilterTypeNameIgnoreCase delegates supplied by the System.Reflection.Module class may also be used, in lieu of the System.Reflection.TypeFilter delegate.
All of the interfaces implemented by this class are considered during the search, whether declared by a base class or this class itself.
This method searches the base class hierarchy, returning each of the matching interfaces each class implements as well as all the matching interfaces each of those interfaces implements (that is, the transitive closure of the matching interfaces is returned). No duplicate interfaces are returned.
If the current Type represents a type parameter in the definition of a generic type or generic method, FindInterfaces searches all the interfaces declared in the constraints on the type parameter, and all interfaces inherited through the interfaces declared in the constraints. If the current Type represents a type argument of a generic type, FindInterfaces searches all the interfaces implemented by the type, whether or not they match constraints.
Note
FindInterfaces can return generic interfaces, even on types that are not generic. For example, a nongeneric type might implement IEnumerable<int> (IEnumerable(Of Integer) in Visual Basic).
