Ver informações do tipo

Artigo
04/01/2024

A classe System.Type é fundamental para reflexão. O Common Language Runtime cria o Type para um tipo carregado quando a reflexão o solicita. Você pode usar métodos, campos, propriedades e classes aninhadas de um objeto Type para descobrir tudo sobre esse tipo.

Use Assembly.GetType ou Assembly.GetTypes para obter Type objetos de assemblies que não foram carregados, passando o nome do tipo ou tipos desejados. Use Type.GetType para obter os objetos Type de um assembly que já está carregado. Use Module.GetType e Module.GetTypes para obter objetos do módulo Type.

Observação

Se você quiser examinar e manipular tipos genéricos e métodos, consulte as informações adicionais fornecidas na Reflexão e tipos genéricos e Como examinar e instanciar tipos genéricos com reflexão.

O exemplo a seguir mostra a sintaxe necessária obter o objeto Assembly e o módulo para um assembly.

// 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

O exemplo a seguir demonstra a obtenção de objetos Type de um assembly carregado.

// 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

Depois de obter um Type, há muitas maneiras de descobrir informações sobre os membros desse tipo. Por exemplo, você pode descobrir sobre todos os membros do tipo chamando o método Type.GetMembers, que obtém uma matriz de objetos MemberInfo que descrevem cada um dos membros do tipo atual.

Você também pode usar métodos na classe Type para recuperar informações sobre um ou mais construtores, métodos, eventos, campos ou propriedades especificados por nome. Por exemplo, Type.GetConstructor encapsula um construtor específico da classe atual.

Se você tiver um Type, poderá usar a propriedade Type.Module para obter um objeto que encapsula o módulo que contém esse tipo. Use a propriedade Module.Assembly para localizar um objeto que encapsula o assembly que contém o módulo. Você pode obter o assembly que encapsula o tipo diretamente usando a propriedade Type.Assembly.

System.Type e ConstructorInfo

O exemplo a seguir mostra como listar os construtores de uma classe, nesse caso, a classe String.

// 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 e PropertyInfo

Obtenha informações sobre métodos, propriedades, eventos e campos do tipo usando os objetos MemberInfo, MethodInfo, FieldInfo ou PropertyInfo.

O exemplo a seguir usa MemberInfo para listar o número de membros na classe System.IO.File e usa a propriedade IsPublic para determinar a visibilidade da classe.

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

O exemplo a seguir examina o tipo do membro especificado. Ele realiza reflexão sobre um membro da classe MemberInfo e lista seu tipo.

// 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

O exemplo a seguir usa todas as classes Reflection *Info junto com BindingFlags para listar todos os membros (construtores, campos, propriedades, eventos e métodos) da classe especificada, dividindo os membros em categorias estáticas e de instância.

// 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

Compartilhar via

Ver informações do tipo

System.Type e ConstructorInfo

MemberInfo, MethodInfo, FieldInfo e PropertyInfo

Recursos adicionais