TypeFilter 代理人

定義

命名空間:

System.Reflection

組件:

System.Runtime.dll

組件:

System.Reflection.dll

組件:

mscorlib.dll

組件:

netstandard.dll

篩選 Type 物件陣列中表示的類別。

public delegate bool TypeFilter(Type ^ m, System::Object ^ filterCriteria);

public delegate bool TypeFilter(Type m, object? filterCriteria);

public delegate bool TypeFilter(Type m, object filterCriteria);

[System.Serializable]
public delegate bool TypeFilter(Type m, object filterCriteria);

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public delegate bool TypeFilter(Type m, object filterCriteria);

type TypeFilter = delegate of Type * obj -> bool

[<System.Serializable>]
type TypeFilter = delegate of Type * obj -> bool

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type TypeFilter = delegate of Type * obj -> bool

Public Delegate Function TypeFilter(m As Type, filterCriteria As Object) As Boolean 

參數

m

Type

要套用篩選條件的 Type 物件。

filterCriteria

Object

用來篩選清單的任意物件。

傳回值

Boolean

若要在篩選清單中包含 Type，則為 true；否則為 false。

屬性

SerializableAttribute ComVisibleAttribute

範例

此範例示範如何定義比對 TypeFilter 委派原型的方法，讓您能夠使用反映來篩選或傳回相符專案的子集。

Imports System.Reflection

' This interface is defined in this assembly.
Public Interface IBookRetailer
    Sub Purchase()
    Sub ApplyDiscount()
End Interface

' This interface is also defined in this assembly.
Public Interface IMusicRetailer
    Sub Purchase()
End Interface

' This class implements three interfaces;
'    Two are defined in this assembly.
'    One is defined in another assembly.
Public Class MyRetailer
    Implements IBookRetailer, IMusicRetailer, IComparable

    ' For demonstration purposes, this method returns nothing.
    Public Function CompareTo(ByVal obj As Object) As Integer Implements System.IComparable.CompareTo
        Return Nothing
    End Function

    ' For demonstration purposes only, this method does nothing.
    Public Sub ApplyDiscount() Implements IBookRetailer.ApplyDiscount
    End Sub

    ' For demonstration purposes only, this method does nothing.
    Public Sub Purchase() Implements IBookRetailer.Purchase
    End Sub

    ' For demonstration purposes only, this method does nothing.
    Public Sub Purchase1() Implements IMusicRetailer.Purchase
    End Sub
End Class

Module Module1
    Sub Main()
        ' Find the interfaces defined by the MyRetailer class. Each interface found is passed to
        ' the TypeFilter method which checks if the interface is defined in the executing assembly.
        Dim retailerType As Type = GetType(MyRetailer)
        Dim interfaces() As Type = _
            retailerType.FindInterfaces(AddressOf TypeFilter, retailerType.Assembly.GetName().ToString())

        ' Show the interfaces that are defined in this assembly that are also implemented by MyRetailer.
        Console.WriteLine("MyRetailer implements the following interfaces (defined in this assembly):")
        For Each t In interfaces
            Console.WriteLine("   {0}", t.Name)
        Next
    End Sub

    ' This method is called by the FindInterfaces method. 
    ' This method is called once per defined interface.
    Function TypeFilter(ByVal t As Type, ByVal filterCriteria As Object) As Boolean
        ' Return true if interface is defined in the same 
        ' assembly identified by the filterCriteria object.
        Return t.Assembly.GetName().ToString() = CType(filterCriteria, String)
    End Function
End Module
' The example displays the following output:
'    MyRetailer implements the following interfaces (defined in this assembly):
'      IBookRetailer
'      IMusicRetailer

備註

委派 TypeFilter 是用來篩選類別清單。 具體而言，您可以使用它來篩選物件陣列中所代表的 Type 類別。 方法 Type.FindInterfaces 會使用此委派來篩選傳回的介面清單。 和 MulticastDelegate 的每個衍生類別 Delegate 都有建構函式和 DynamicInvoke 方法。 請參閱 描述 Delegate 中提供的 Visual C++ 程式碼範例。

擴充方法

GetMethodInfo(Delegate)

取得表示特定委派所代表之方法的物件。

另請參閱

• FindInterfaces(TypeFilter, Object)
• Object
• Delegate
• MulticastDelegate