Type.GetConstructor Method (BindingFlags, Binder, array<Type[], array<ParameterModifier[])

Parameters

• bindingAttr
  Type: System.Reflection.BindingFlags
  A bitmask comprised of one or more BindingFlags that specify how the search is conducted.
  -or-
  Zero, to return nulla null reference (Nothing in Visual Basic).

• binder
  Type: System.Reflection.Binder
  A Binder object that defines a set of properties and enables binding, which can involve selection of an overloaded method, coercion of argument types, and invocation of a member through reflection.
  -or-
  A null reference (Nothing in Visual Basic), to use the DefaultBinder.

• types
  Type: array<System.Type[]
  An array of Type objects representing the number, order, and type of the parameters for the constructor to get.
  -or-
  An empty array of the type Type (that is, Type[] types = new Type[0]) to get a constructor that takes no parameters.
  -or-
  EmptyTypes .

• modifiers
  Type: array<System.Reflection.ParameterModifier[]
  An array of ParameterModifier objects representing the attributes associated with the corresponding element in the parameter type array. The default binder does not process this parameter.

Return Value

Type: System.Reflection.ConstructorInfo
A ConstructorInfo object representing the constructor that matches the specified requirements, if found; otherwise, nulla null reference (Nothing in Visual Basic).

Public Class Example
    Public Sub New(ByVal i As Integer)
    End Sub

    Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

         Dim myType As Type = GetType(Example)
         Dim parameters() As Type = { GetType(Int32) }

         ' Get the public instance constructor that takes an integer parameter.
         Dim ctor As ConstructorInfo = myType.GetConstructor( _
             BindingFlags.Instance Or BindingFlags.Public, _
             Type.DefaultBinder, _
             parameters, _
             Nothing)

         If ctor Is Nothing Then
             outputBlock.Text &= _
                 "There is no public instance constructor of MyClass " & _
                 "that takes an integer as a parameter." & vbCrLf
         Else
             outputBlock.Text &= _
                 "The public constructor of MyClass that takes an integer " & _
                 "as a parameter is: " & vbCrLf
             outputBlock.Text &= ctor.ToString() & vbCrLf
         End If

    End Sub 
End Class 

' This example produces the following output:
'
'The public constructor of MyClass that takes an integer as a parameter is:
'Void .ctor(Int32)

using System;
using System.Reflection;
using System.Security;

public class Example
{
    public Example(int i) { }

    public static void Demo(System.Windows.Controls.TextBlock outputBlock)
    {
        Type myType = typeof(Example);
        Type[] parameters = { typeof(int) };

        // Get the constructor that takes an integer as a parameter.
        ConstructorInfo ctor = myType.GetConstructor(
            BindingFlags.Instance | BindingFlags.Public, 
            Type.DefaultBinder,
            parameters,
            null);

        if (ctor == null)
        {
            outputBlock.Text += 
                "There is no public constructor of MyClass that takes an integer as a parameter.\n";
        }
        else
        {
            outputBlock.Text += 
                "The public constructor of MyClass that takes an integer as a parameter is:\n"; 
            outputBlock.Text += ctor.ToString() + "\n";
        }
    }
}

/* This example produces the following output:

The public constructor of MyClass that takes an integer as a parameter is:
Void .ctor(Int32)
 */