Visa typinformation

Artikel
03/30/2024

Klassen System.Type är central för reflektion. Den vanliga språkkörningen Type skapar för en inläst typ när reflektion begär det. Du kan använda ett Type objekts metoder, fält, egenskaper och kapslade klasser för att ta reda på allt om den typen.

Använd Assembly.GetType eller Assembly.GetTypes för att hämta Type objekt från sammansättningar som inte har lästs in, och skicka in namnet på den typ eller de typer som du vill använda. Använd Type.GetType för att hämta objekten Type från en sammansättning som redan har lästs in. Använd Module.GetType och Module.GetTypes för att hämta modulobjekt Type .

Kommentar

Om du vill undersöka och manipulera generiska typer och metoder kan du läsa mer i Reflektion och Allmänna typer och Så här: Granska och instansiera generiska typer med reflektion.

I följande exempel visas den syntax som krävs för att hämta Assembly objektet och modulen för en sammansättning.

// Gets the mscorlib assembly in which the object is defined.
Assembly^ a = Object::typeid->Module->Assembly;

// Gets the mscorlib assembly in which the object is defined.
Assembly a = typeof(object).Module.Assembly;

' Gets the mscorlib assembly in which the object is defined.
Dim a As Assembly = GetType(Object).Module.Assembly

I följande exempel visas hur du hämtar Type objekt från en inläst sammansättning.

// Loads an assembly using its file name.
Assembly^ a = Assembly::LoadFrom("MyExe.exe");
// Gets the type names from the assembly.
array<Type^>^ types2 = a->GetTypes();
for each (Type^ t in types2)
{
    Console::WriteLine(t->FullName);
}

// Loads an assembly using its file name.
Assembly a = Assembly.LoadFrom("MyExe.exe");
// Gets the type names from the assembly.
Type[] types2 = a.GetTypes();
foreach (Type t in types2)
{
    Console.WriteLine(t.FullName);
}

' Loads an assembly using its file name.
Dim a As Assembly = Assembly.LoadFrom("MyExe.exe")
' Gets the type names from the assembly.
Dim types2() As Type = a.GetTypes()
For Each t As Type In types2
    Console.WriteLine(t.FullName)
Next t

När du har fått en Typefinns det många sätt att identifiera information om medlemmar av den typen. Du kan till exempel ta reda på om alla medlemmar i typen genom att anropa Type.GetMembers metoden, som hämtar en matris med MemberInfo objekt som beskriver var och en av medlemmarna av den aktuella typen.

Du kan också använda metoder i Type klassen för att hämta information om en eller flera konstruktorer, metoder, händelser, fält eller egenskaper som du anger med namn. Kapslar till exempel Type.GetConstructor in en specifik konstruktor för den aktuella klassen.

Om du har en Typekan du använda Type.Module egenskapen för att hämta ett objekt som kapslar in modulen som innehåller den typen. Använd egenskapen Module.Assembly för att hitta ett objekt som kapslar in sammansättningen som innehåller modulen. Du kan hämta sammansättningen som kapslar in typen direkt med hjälp Type.Assembly av egenskapen .

System.Type och ConstructorInfo

I följande exempel visas hur du listar konstruktorerna för en klass, i det här fallet String klassen.

// This program lists all the public constructors
// of the System.String class.
using namespace System;
using namespace System::Reflection;

class ListMembers
{
public:
    static void Main()
    {
        Type^ t = System::String::typeid;
        Console::WriteLine ("Listing all the public constructors of the {0} type", t);
        // Constructors.
        array<ConstructorInfo^>^ ci = t->GetConstructors(BindingFlags::Public | BindingFlags::Instance);
        Console::WriteLine ("//Constructors");
        PrintMembers(ci);
    }

    static void PrintMembers(array<MemberInfo^>^ ms)
    {
        for each (MemberInfo^ m in ms)
        {
            Console::WriteLine ("{0}{1}", "     ", m);
        }
        Console::WriteLine();
    }
};

int main()
{
    ListMembers::Main();
}

// This program lists all the public constructors
// of the System.String class.
using System;
using System.Reflection;

class ListMembers
{
    public static void Main()
    {
        Type t = typeof(System.String);
        Console.WriteLine("Listing all the public constructors of the {0} type", t);
        // Constructors.
        ConstructorInfo[] ci = t.GetConstructors(BindingFlags.Public | BindingFlags.Instance);
        Console.WriteLine("//Constructors");
        PrintMembers(ci);
    }

    public static void PrintMembers(MemberInfo[] ms)
    {
        foreach (MemberInfo m in ms)
        {
            Console.WriteLine("{0}{1}", "     ", m);
        }
        Console.WriteLine();
    }
}

' This program lists all the public constructors
' of the System.String class.

Imports System.Reflection

Class ListMembers
    Public Shared Sub Main()
        Dim t As Type = GetType(String)
        Console.WriteLine("Listing all the public constructors of the {0} type", t)
        ' Constructors.
        Dim ci As ConstructorInfo() = t.GetConstructors((BindingFlags.Public Or BindingFlags.Instance))
        Console.WriteLine("//Constructors")
        PrintMembers(ci)
    End Sub
    Public Shared Sub PrintMembers(ms() As MemberInfo)
        Dim m As MemberInfo
        For Each m In ms
            Console.WriteLine("{0}{1}", "     ", m)
        Next m
        Console.WriteLine()
    End Sub
End Class

MemberInfo, MethodInfo, FieldInfo och PropertyInfo

Hämta information om typens metoder, egenskaper, händelser och fält med hjälp av MemberInfo, MethodInfo, FieldInfoeller PropertyInfo objekt.

I följande exempel används MemberInfo för att visa antalet medlemmar i System.IO.File klassen och egenskapen används IsPublic för att fastställa klassens synlighet.

using namespace System;
using namespace System::IO;
using namespace System::Reflection;

public ref class MyMemberInfo
{
public:
    static void Main()
    {
        Console::WriteLine ("\nReflection.MemberInfo");
        // Gets the Type and MemberInfo.
        Type^ myType = Type::GetType("System.IO.File");
        array<MemberInfo^>^ myMemberInfoArray = myType->GetMembers();
        // Gets and displays the DeclaringType method.
        Console::WriteLine("\nThere are {0} members in {1}.",
            myMemberInfoArray->Length, myType->FullName);
        Console::WriteLine("{0}.", myType->FullName);
        if (myType->IsPublic)
        {
            Console::WriteLine("{0} is public.", myType->FullName);
        }
    }
};

int main()
{
    MyMemberInfo::Main();
}

using System;
using System.IO;
using System.Reflection;

class MyMemberInfo
{
    public static void Main()
    {
        Console.WriteLine ("\nReflection.MemberInfo");
        // Gets the Type and MemberInfo.
        Type myType = Type.GetType("System.IO.File");
        MemberInfo[] myMemberInfoArray = myType.GetMembers();
        // Gets and displays the DeclaringType method.
        Console.WriteLine("\nThere are {0} members in {1}.",
            myMemberInfoArray.Length, myType.FullName);
        Console.WriteLine("{0}.", myType.FullName);
        if (myType.IsPublic)
        {
            Console.WriteLine("{0} is public.", myType.FullName);
        }
    }
}

Imports System.IO
Imports System.Reflection

Class MyMemberInfo
    Public Shared Sub Main()
        Console.WriteLine("\nReflection.MemberInfo")
        ' Gets the Type and MemberInfo.
        Dim myType As Type = Type.GetType("System.IO.File")
        Dim myMemberInfoArray() As MemberInfo = myType.GetMembers()
        ' Gets and displays the DeclaringType method.
        Console.WriteLine("\nThere are {0} members in {1}.",
            myMemberInfoArray.Length, myType.FullName)
        Console.WriteLine("{0}.", myType.FullName)
        If myType.IsPublic
            Console.WriteLine("{0} is public.", myType.FullName)
        End If
    End Sub
End Class

I följande exempel undersöks typen av angiven medlem. Den utför reflektion på en medlem i MemberInfo klassen och visar en lista över dess typ.

// This code displays information about the GetValue method of FieldInfo.
using namespace System;
using namespace System::Reflection;

public ref class MyMethodInfo
{
public:
    static int Main()
    {
        Console::WriteLine("Reflection.MethodInfo");
        // Gets and displays the Type.
        Type^ myType = Type::GetType("System.Reflection.FieldInfo");
        // Specifies the member for which you want type information.
        MethodInfo^ myMethodInfo = myType->GetMethod("GetValue");
        Console::WriteLine(myType->FullName + "." + myMethodInfo->Name);
        // Gets and displays the MemberType property.
        MemberTypes myMemberTypes = myMethodInfo->MemberType;
        if (MemberTypes::Constructor == myMemberTypes)
        {
            Console::WriteLine("MemberType is of type All");
        }
        else if (MemberTypes::Custom == myMemberTypes)
        {
            Console::WriteLine("MemberType is of type Custom");
        }
        else if (MemberTypes::Event == myMemberTypes)
        {
            Console::WriteLine("MemberType is of type Event");
        }
        else if (MemberTypes::Field == myMemberTypes)
        {
            Console::WriteLine("MemberType is of type Field");
        }
        else if (MemberTypes::Method == myMemberTypes)
        {
            Console::WriteLine("MemberType is of type Method");
        }
        else if (MemberTypes::Property == myMemberTypes)
        {
            Console::WriteLine("MemberType is of type Property");
        }
        else if (MemberTypes::TypeInfo == myMemberTypes)
        {
            Console::WriteLine("MemberType is of type TypeInfo");
        }
        return 0;
    }
};

int main()
{
    MyMethodInfo::Main();
}

// This code displays information about the GetValue method of FieldInfo.
using System;
using System.Reflection;

class MyMethodInfo
{
    public static int Main()
    {
        Console.WriteLine("Reflection.MethodInfo");
        // Gets and displays the Type.
        Type myType = Type.GetType("System.Reflection.FieldInfo");
        // Specifies the member for which you want type information.
        MethodInfo myMethodInfo = myType.GetMethod("GetValue");
        Console.WriteLine(myType.FullName + "." + myMethodInfo.Name);
        // Gets and displays the MemberType property.
        MemberTypes myMemberTypes = myMethodInfo.MemberType;
        if (MemberTypes.Constructor == myMemberTypes)
        {
            Console.WriteLine("MemberType is of type All");
        }
        else if (MemberTypes.Custom == myMemberTypes)
        {
            Console.WriteLine("MemberType is of type Custom");
        }
        else if (MemberTypes.Event == myMemberTypes)
        {
            Console.WriteLine("MemberType is of type Event");
        }
        else if (MemberTypes.Field == myMemberTypes)
        {
            Console.WriteLine("MemberType is of type Field");
        }
        else if (MemberTypes.Method == myMemberTypes)
        {
            Console.WriteLine("MemberType is of type Method");
        }
        else if (MemberTypes.Property == myMemberTypes)
        {
            Console.WriteLine("MemberType is of type Property");
        }
        else if (MemberTypes.TypeInfo == myMemberTypes)
        {
            Console.WriteLine("MemberType is of type TypeInfo");
        }
        return 0;
    }
}

' This code displays information about the GetValue method of FieldInfo.
Imports System.Reflection
Class MyMethodInfo
    Public Shared Sub Main()
        Console.WriteLine("Reflection.MethodInfo")
        ' Gets and displays the Type.
        Dim myType As Type = Type.GetType("System.Reflection.FieldInfo")
        ' Specifies the member for which you want type information.
        Dim myMethodInfo As MethodInfo = myType.GetMethod("GetValue")
        Console.WriteLine((myType.FullName & "." & myMethodInfo.Name))
        ' Gets and displays the MemberType property.
        Dim myMemberTypes As MemberTypes = myMethodInfo.MemberType
        If MemberTypes.Constructor = myMemberTypes Then
            Console.WriteLine("MemberType is of type All")
        ElseIf MemberTypes.Custom = myMemberTypes Then
            Console.WriteLine("MemberType is of type Custom")
        ElseIf MemberTypes.Event = myMemberTypes Then
            Console.WriteLine("MemberType is of type Event")
        ElseIf MemberTypes.Field = myMemberTypes Then
            Console.WriteLine("MemberType is of type Field")
        ElseIf MemberTypes.Method = myMemberTypes Then
            Console.WriteLine("MemberType is of type Method")
        ElseIf MemberTypes.Property = myMemberTypes Then
            Console.WriteLine("MemberType is of type Property")
        ElseIf MemberTypes.TypeInfo = myMemberTypes Then
            Console.WriteLine("MemberType is of type TypeInfo")
        End If
        Return
    End Sub
End Class

I följande exempel används alla reflektionsklasser *Info tillsammans med BindingFlags för att visa alla medlemmar (konstruktorer, fält, egenskaper, händelser och metoder) i den angivna klassen, vilket delar upp medlemmarna i statiska kategorier och instanskategorier.

// This program lists all the members of the
// System.IO.BufferedStream class.
using namespace System;
using namespace System::IO;
using namespace System::Reflection;

public ref class ListMembers
{
public:
    static void Main()
    {
        // Specifies the class.
        Type^ t = System::IO::BufferedStream::typeid;
        Console::WriteLine("Listing all the members (public and non public) of the {0} type", t);

        // Lists static fields first.
        array<FieldInfo^>^ fi = t->GetFields(BindingFlags::Static |
            BindingFlags::NonPublic | BindingFlags::Public);
        Console::WriteLine("// Static Fields");
        PrintMembers(fi);

        // Static properties.
        array<PropertyInfo^>^ pi = t->GetProperties(BindingFlags::Static |
            BindingFlags::NonPublic | BindingFlags::Public);
        Console::WriteLine("// Static Properties");
        PrintMembers(pi);

        // Static events.
        array<EventInfo^>^ ei = t->GetEvents(BindingFlags::Static |
            BindingFlags::NonPublic | BindingFlags::Public);
        Console::WriteLine("// Static Events");
        PrintMembers(ei);

        // Static methods.
        array<MethodInfo^>^ mi = t->GetMethods (BindingFlags::Static |
            BindingFlags::NonPublic | BindingFlags::Public);
        Console::WriteLine("// Static Methods");
        PrintMembers(mi);

        // Constructors.
        array<ConstructorInfo^>^ ci = t->GetConstructors(BindingFlags::Instance |
            BindingFlags::NonPublic | BindingFlags::Public);
        Console::WriteLine("// Constructors");
        PrintMembers(ci);

        // Instance fields.
        fi = t->GetFields(BindingFlags::Instance | BindingFlags::NonPublic |
            BindingFlags::Public);
        Console::WriteLine("// Instance Fields");
        PrintMembers(fi);

        // Instance properties.
        pi = t->GetProperties(BindingFlags::Instance | BindingFlags::NonPublic |
            BindingFlags::Public);
        Console::WriteLine ("// Instance Properties");
        PrintMembers(pi);

        // Instance events.
        ei = t->GetEvents(BindingFlags::Instance | BindingFlags::NonPublic |
            BindingFlags::Public);
        Console::WriteLine("// Instance Events");
        PrintMembers(ei);

        // Instance methods.
        mi = t->GetMethods(BindingFlags::Instance | BindingFlags::NonPublic
            | BindingFlags::Public);
        Console::WriteLine("// Instance Methods");
        PrintMembers(mi);

        Console::WriteLine("\r\nPress ENTER to exit.");
        Console::Read();
    }

    static void PrintMembers(array<MemberInfo^>^ ms)
    {
        for each (MemberInfo^ m in ms)
        {
            Console::WriteLine ("{0}{1}", "     ", m);
        }
        Console::WriteLine();
    }
};

int main()
{
    ListMembers::Main();
}

// This program lists all the members of the
// System.IO.BufferedStream class.
using System;
using System.IO;
using System.Reflection;

class ListMembers
{
    public static void Main()
    {
        // Specifies the class.
        Type t = typeof(System.IO.BufferedStream);
        Console.WriteLine("Listing all the members (public and non public) of the {0} type", t);

        // Lists static fields first.
        FieldInfo[] fi = t.GetFields(BindingFlags.Static |
            BindingFlags.NonPublic | BindingFlags.Public);
        Console.WriteLine("// Static Fields");
        PrintMembers(fi);

        // Static properties.
        PropertyInfo[] pi = t.GetProperties(BindingFlags.Static |
            BindingFlags.NonPublic | BindingFlags.Public);
        Console.WriteLine("// Static Properties");
        PrintMembers(pi);

        // Static events.
        EventInfo[] ei = t.GetEvents(BindingFlags.Static |
            BindingFlags.NonPublic | BindingFlags.Public);
        Console.WriteLine("// Static Events");
        PrintMembers(ei);

        // Static methods.
        MethodInfo[] mi = t.GetMethods (BindingFlags.Static |
            BindingFlags.NonPublic | BindingFlags.Public);
        Console.WriteLine("// Static Methods");
        PrintMembers(mi);

        // Constructors.
        ConstructorInfo[] ci = t.GetConstructors(BindingFlags.Instance |
            BindingFlags.NonPublic | BindingFlags.Public);
        Console.WriteLine("// Constructors");
        PrintMembers(ci);

        // Instance fields.
        fi = t.GetFields(BindingFlags.Instance | BindingFlags.NonPublic |
            BindingFlags.Public);
        Console.WriteLine("// Instance Fields");
        PrintMembers(fi);

        // Instance properties.
        pi = t.GetProperties(BindingFlags.Instance | BindingFlags.NonPublic |
            BindingFlags.Public);
        Console.WriteLine ("// Instance Properties");
        PrintMembers(pi);

        // Instance events.
        ei = t.GetEvents(BindingFlags.Instance | BindingFlags.NonPublic |
            BindingFlags.Public);
        Console.WriteLine("// Instance Events");
        PrintMembers(ei);

        // Instance methods.
        mi = t.GetMethods(BindingFlags.Instance | BindingFlags.NonPublic
            | BindingFlags.Public);
        Console.WriteLine("// Instance Methods");
        PrintMembers(mi);

        Console.WriteLine("\r\nPress ENTER to exit.");
        Console.Read();
    }

    public static void PrintMembers (MemberInfo [] ms)
    {
        foreach (MemberInfo m in ms)
        {
            Console.WriteLine ("{0}{1}", "     ", m);
        }
        Console.WriteLine();
    }
}

' This program lists all the members of the
' System.IO.BufferedStream class.
Imports System.IO
Imports System.Reflection

Class ListMembers
    Public Shared Sub Main()
        ' Specifies the class.
        Dim t As Type = GetType(System.IO.BufferedStream)
        Console.WriteLine("Listing all the members (public and non public) of the {0} type", t)
        ' Lists static fields first.
        Dim fi As FieldInfo() = t.GetFields((BindingFlags.Static Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Static Fields")
        PrintMembers(fi)
        ' Static properties.
        Dim pi As PropertyInfo() = t.GetProperties((BindingFlags.Static Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Static Properties")
        PrintMembers(pi)
        ' Static events.
        Dim ei As EventInfo() = t.GetEvents((BindingFlags.Static Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Static Events")
        PrintMembers(ei)
        ' Static methods.
        Dim mi As MethodInfo() = t.GetMethods((BindingFlags.Static Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Static Methods")
        PrintMembers(mi)
        ' Constructors.
        Dim ci As ConstructorInfo() = t.GetConstructors((BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Constructors")
        PrintMembers(ci)
        ' Instance fields.
        fi = t.GetFields((BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Instance Fields")
        PrintMembers(fi)
        ' Instance properties.
        pi = t.GetProperties((BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Instance Properties")
        PrintMembers(pi)
        ' Instance events.
        ei = t.GetEvents((BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Instance Events")
        PrintMembers(ei)
        ' Instance methods.
        mi = t.GetMethods((BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Instance Methods")
        PrintMembers(mi)
        Console.WriteLine(ControlChars.CrLf & "Press ENTER to exit.")
        Console.Read()
    End Sub

    Public Shared Sub PrintMembers(ms() As MemberInfo)
        Dim m As MemberInfo
        For Each m In ms
            Console.WriteLine("{0}{1}", "     ", m)
        Next m
        Console.WriteLine()
    End Sub
End Class

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Visa typinformation

System.Type och ConstructorInfo

MemberInfo, MethodInfo, FieldInfo och PropertyInfo

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