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Type.GetConstructors Method ()

Returns all the public constructors defined for the current Type.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

[ComVisibleAttribute(true)] 
public ConstructorInfo[] GetConstructors ()
/** @attribute ComVisibleAttribute(true) */ 
public final ConstructorInfo[] GetConstructors ()
ComVisibleAttribute(true) 
public final function GetConstructors () : ConstructorInfo[]
Not applicable.

Return Value

An array of ConstructorInfo objects representing all the public instance constructors defined for the current Type, but not including the type initializer (static constructor). If no public instance constructors are defined for the current Type, or if the current Type represents a type parameter in the definition of a generic type or generic method, an empty array of type ConstructorInfo is returned.

The GetConstructors method does not return constructors in a particular order, such as declaration order. Your code must not depend on the order in which constructors are returned, because that order varies.

The following table shows what members of a base class are returned by the Get methods when reflecting on a type.

Member Type

Static

Non-Static

Constructor

No

No

Field

No

Yes. A field is always hide-by-name-and-signature.

Event

Not applicable

The common type system rule is that the inheritance is the same as that of the methods that implement the property. Reflection treats properties as hide-by-name-and-signature. See note 2 below.

Method

No

Yes. A method (both virtual and non-virtual) can be hide-by-name or hide-by-name-and-signature.

Nested Type

No

No

Property

Not applicable

The common type system rule is that the inheritance is the same as that of the methods that implement the property. Reflection treats properties as hide-by-name-and-signature. See note 2 below.

  1. Hide-by-name-and-signature considers all of the parts of the signature, including custom modifiers, return types, parameter types, sentinels, and unmanaged calling conventions. This is a binary comparison.

  2. For reflection, properties and events are hide-by-name-and-signature. If you have a property with both a get and a set accessor in the base class, but the derived class has only a get accessor, the derived class property hides the base class property, and you will not be able to access the setter on the base class.

  3. Custom attributes are not part of the common type system.

This method overload calls the GetConstructors(BindingFlags) method overload, with BindingFlags.Public | BindingFlags.Instance (BindingFlags.PublicOrBindingFlags.Instance in Visual Basic). It will not find class initializers (.cctor). To find class initializers, use an overload that takes BindingFlags, and specify BindingFlags.Static | BindingFlags.NonPublic (BindingFlags.StaticOrBindingFlags.NonPublic in Visual Basic). You can also get the class initializer using the TypeInitializer property.

If the current Type represents a constructed generic type, this method returns the ConstructorInfo objects with the type parameters replaced by the appropriate type arguments. For example, if class C<T> has a constructor C(T t1) (Sub New(ByVal t1 As T) in Visual Basic), calling GetConstructors on C<int> returns a ConstructorInfo that represents C(int t1) in C# (Sub New(ByVal t1 As Integer) in Visual Basic).

If the current Type represents a generic type parameter, the GetConstructors method returns an empty array.

This example shows the output of the GetConstructors overload from a class that has two instance constructors and one static constructor.

using System;
using System.Reflection;

public class t {
    public t() {}
    static t() {}
    public t(int i) {}

    public static void Main() {
        ConstructorInfo[] p = typeof(t).GetConstructors();
        Console.WriteLine(p.Length);

        for (int i=0;i<p.Length;i++) {
            Console.WriteLine(p[i].IsStatic);
        }
    }
}

import System.*;
import System.Reflection.*;

public class T
{
    public T()
    {
    } //T

    static 
    {
    } //T

    public T(int i)
    {
    } //T

    public static void main(String[] args)
    {
        ConstructorInfo p[] = T.class.ToType().GetConstructors();
        Console.WriteLine(p.length);
        for (int i=0;i < p.length;i++) {
            Console.WriteLine(p[i].get_IsStatic());
        } 
    } //main
} //T

import System;
import System.Reflection;

public class t {
    public function t() {}
    static t {}
    public function t(i : int) {}

    public static function Main(): void  {
        var p : ConstructorInfo[] = t.GetConstructors();
        Console.WriteLine(p.Length);

        for (var i : int =0;i<p.Length;i++) {
            Console.WriteLine(p[i].IsStatic);
        }
    }
}
t.Main();

The output of this code is:

2

False

False

Because the GetConstructors overload uses only BindingFlags.Public and BindingFlags.Instance, the static constructor is neither counted by the for expression nor evaluated by IsStatic.

To find static constructors, use the GetConstructors(BindingFlags) overload, and pass the combination (logical OR) of BindingFlags.Public, BindingFlags.Static, BindingFlags.NonPublic, BindingFlags.Instance, as shown in the following code example:

using System;
using System.Reflection;
 
public class t {
    public t() {}
    static t() {}
    public t(int i) {}

    public static void Main() {
        ConstructorInfo[] p = typeof(t).GetConstructors(
           BindingFlags.Public | BindingFlags.Static |
           BindingFlags.NonPublic | BindingFlags.Instance);
        Console.WriteLine(p.Length);

        for (int i=0;i<p.Length;i++) {
            Console.WriteLine(p[i].IsStatic);
        }
    }
}

import System.*;
import System.Reflection.*;

public class T
{
    public T() 
    {
    } //T

    static
    {
    } //T

    public T(int i)
    {
    } //T

    public static void main(String[] args)
    {
        ConstructorInfo p[] = T.class.ToType().GetConstructors(
            (BindingFlags.Public | BindingFlags.Static | BindingFlags.NonPublic
            | BindingFlags.Instance)); 
        Console.WriteLine(p.length);
        for (int i=0;i< p.length;i++) {
            Console.WriteLine(p[i].get_IsStatic());
        } 
    } //main
} //T

import System;
import System.Reflection;
 
public class t {
    public function t() {}
    static t {}
    public function t(i : int) {}

    public static function Main() : void  {
        var p : ConstructorInfo[] = t.GetConstructors(
           BindingFlags.Public | BindingFlags.Static |
           BindingFlags.NonPublic | BindingFlags.Instance);
        Console.WriteLine(p.Length);

        for (var i:int=0;i<p.Length;i++) {
            Console.WriteLine(p[i].IsStatic);
        }
    }
}
t.Main();

Now the output is:

3

False

True

False

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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