ConstructorInfo
Class
Definition
Discovers the attributes of a class constructor and provides access to constructor metadata.
[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class ConstructorInfo : System.Reflection.MethodBase, System.Runtime.InteropServices._ConstructorInfo
- Inheritance
- Derived
- Attributes
- Implements
Inherited Members
System.Object
System.Reflection.MemberInfo
System.Reflection.MethodBase
Examples
The following example uses ConstructorInfo with GetConstructor and BindingFlags to find the constructors that match the specified search criteria.
using namespace System;
using namespace System::Reflection;
using namespace System::Security;
public ref class MyClass1
{
public:
MyClass1( int i ){}
};
int main()
{
try
{
Type^ myType = MyClass1::typeid;
array<Type^>^types = gcnew array<Type^>(1);
types[ 0 ] = int::typeid;
// Get the public instance constructor that takes an integer parameter.
ConstructorInfo^ constructorInfoObj = myType->GetConstructor( static_cast<BindingFlags>(BindingFlags::Instance | BindingFlags::Public), nullptr, CallingConventions::HasThis, types, nullptr );
if ( constructorInfoObj != nullptr )
{
Console::WriteLine( "The constructor of MyClass1 that is a public instance method and takes an integer as a parameter is: " );
Console::WriteLine( constructorInfoObj );
}
else
{
Console::WriteLine( "The constructor of MyClass1 that is a public instance method and takes an integer as a parameter is not available." );
}
}
catch ( ArgumentNullException^ e )
{
Console::WriteLine( "ArgumentNullException: {0}", e->Message );
}
catch ( ArgumentException^ e )
{
Console::WriteLine( "ArgumentException: {0}", e->Message );
}
catch ( SecurityException^ e )
{
Console::WriteLine( "SecurityException: {0}", e->Message );
}
catch ( Exception^ e )
{
Console::WriteLine( "Exception: {0}", e->Message );
}
}
using System;
using System.Reflection;
using System.Security;
public class MyClass1
{
public MyClass1(int i){}
public static void Main()
{
try
{
Type myType = typeof(MyClass1);
Type[] types = new Type[1];
types[0] = typeof(int);
// Get the public instance constructor that takes an integer parameter.
ConstructorInfo constructorInfoObj = myType.GetConstructor(
BindingFlags.Instance | BindingFlags.Public, null,
CallingConventions.HasThis, types, null);
if(constructorInfoObj != null)
{
Console.WriteLine("The constructor of MyClass1 that is a public " +
"instance method and takes an integer as a parameter is: ");
Console.WriteLine(constructorInfoObj.ToString());
}
else
{
Console.WriteLine("The constructor of MyClass1 that is a public instance " +
"method and takes an integer as a parameter is not available.");
}
}
catch(ArgumentNullException e)
{
Console.WriteLine("ArgumentNullException: " + e.Message);
}
catch(ArgumentException e)
{
Console.WriteLine("ArgumentException: " + e.Message);
}
catch(SecurityException e)
{
Console.WriteLine("SecurityException: " + e.Message);
}
catch(Exception e)
{
Console.WriteLine("Exception: " + e.Message);
}
}
}
Public Class MyClass1
Public Sub New(ByVal i As Integer)
End Sub
Public Shared Sub Main()
Try
Dim myType As Type = GetType(MyClass1)
Dim types(0) As Type
types(0) = GetType(Integer)
' Get the public instance constructor that takes an integer parameter.
Dim constructorInfoObj As ConstructorInfo = _
myType.GetConstructor(BindingFlags.Instance Or _
BindingFlags.Public, Nothing, _
CallingConventions.HasThis, types, Nothing)
If Not (constructorInfoObj Is Nothing) Then
Console.WriteLine("The constructor of MyClass1 that " + _
"is a public instance method and takes an " + _
"integer as a parameter is: ")
Console.WriteLine(constructorInfoObj.ToString())
Else
Console.WriteLine("The constructor MyClass1 that " + _
"is a public instance method and takes an " + _
"integer as a parameter is not available.")
End If
Catch e As ArgumentNullException
Console.WriteLine("ArgumentNullException: " + e.Message)
Catch e As ArgumentException
Console.WriteLine("ArgumentException: " + e.Message)
Catch e As SecurityException
Console.WriteLine("SecurityException: " + e.Message)
Catch e As Exception
Console.WriteLine("Exception: " + e.Message)
End Try
End Sub
End Class
Remarks
ConstructorInfo is used to discover the attributes of a constructor as well as to invoke a constructor. Objects are created by calling Invoke on a ConstructorInfo returned by either the GetConstructors or GetConstructor method of a Type object.
Note
ConstructorInfo inherits from MethodBase several members, such as IsGenericMethod, that can be used to examine generic methods. In the .NET Framework version 2.0 constructors cannot be generic, so these members return false or null.
Constructors
| ConstructorInfo() |
Initializes a new instance of the ConstructorInfo class. |
Fields
| ConstructorName |
Represents the name of the class constructor method as it is stored in metadata. This name is always ".ctor". This field is read-only. |
| TypeConstructorName |
Represents the name of the type constructor method as it is stored in metadata. This name is always ".cctor". This property is read-only. |
Properties
| MemberType |
Gets a MemberTypes value indicating that this member is a constructor. |
Methods
| Equals(Object) |
Returns a value that indicates whether this instance is equal to a specified object. |
| GetHashCode() |
Returns the hash code for this instance. |
| Invoke(Object[]) |
Invokes the constructor reflected by the instance that has the specified parameters, providing default values for the parameters not commonly used. |
| Invoke(BindingFlags, Binder, Object[], CultureInfo) |
When implemented in a derived class, invokes the constructor reflected by this |
Operators
| Equality(ConstructorInfo, ConstructorInfo) |
Indicates whether two ConstructorInfo objects are equal. |
| Inequality(ConstructorInfo, ConstructorInfo) |
Indicates whether two ConstructorInfo objects are not equal. |
Explicit Interface Implementations
Extension Methods
Thread Safety
This type is thread safe.