Type.GetMethod Method (String, BindingFlags, Binder, CallingConventions, array<Type[], array<ParameterModifier[])

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Searches for the specified method whose parameters match the specified argument types and modifiers, using the specified binding constraints and the specified calling convention.

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

Syntax

'Declaration
Public Function GetMethod ( _
    name As String, _
    bindingAttr As BindingFlags, _
    binder As Binder, _
    callConvention As CallingConventions, _
    types As Type(), _
    modifiers As ParameterModifier() _
) As MethodInfo

public MethodInfo GetMethod(
    string name,
    BindingFlags bindingAttr,
    Binder binder,
    CallingConventions callConvention,
    Type[] types,
    ParameterModifier[] modifiers
)

Parameters

• name
  Type: System.String
  The String containing the name of the method to get.

• 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.

• callConvention
  Type: System.Reflection.CallingConventions
  The CallingConventions object that specifies the set of rules to use regarding the order and layout of arguments, how the return value is passed, what registers are used for arguments, and how the stack is cleaned up.

• types
  Type: array<System.Type[]
  An array of Type objects representing the number, order, and type of the parameters for the method to get.
  -or-
  An empty array of Type objects (as provided by the EmptyTypes field) to get a method that takes no parameters.

• modifiers
  Type: array<System.Reflection.ParameterModifier[]
  An array of ParameterModifier objects representing the attributes associated with the corresponding element in the types array. To be only used when calling through COM interop, and only parameters that are passed by reference are handled. The default binder does not process this parameter.

Return Value

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

Exceptions

Exception	Condition
AmbiguousMatchException	More than one method is found with the specified name and matching the specified binding constraints.
ArgumentNullException	name is nulla null reference (Nothing in Visual Basic). -or- types is nulla null reference (Nothing in Visual Basic). -or- One of the elements in types is nulla null reference (Nothing in Visual Basic).
ArgumentException	types is multidimensional. -or- modifiers is multidimensional.

Remarks

Although the default binder does not process ParameterModifier (the modifiers parameter), you can use the abstract System.Reflection.Binder class to write a custom binder that does process modifiers. ParameterModifier is only used when calling through COM interop, and only parameters that are passed by reference are handled.

The following table shows what members of a base class are returned by the GetXXX 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.

Notes:

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.

The types array and the modifiers array have the same length. A parameter specified in the types array can have the following attributes, which are specified in the modifiers array: pdIn, pdOut, pdLcid, pdRetval, pdOptional, and pdHasDefault, which represent [In], [Out], [lcid], [retval], [optional], and a value specifying whether the parameter has a default value. A parameter's associated attributes are stored in the metadata and enhance interoperability.

The following BindingFlags filter flags can be used to define which methods to include in the search:

• You must specify either BindingFlags.Instance or BindingFlags.Static in order to get a return.

• Specify BindingFlags.Public to include public methods in the search.

• Specify BindingFlags.NonPublic to include nonpublic methods (that is, private and protected methods) in the search.

• Specify BindingFlags.FlattenHierarchy to include public and protected static members up the hierarchy; private static members in inherited classes are not included.

The following BindingFlags modifier flags can be used to change how the search works:

• BindingFlags.IgnoreCase to ignore the case of name.

• BindingFlags.DeclaredOnly to search only the methods declared on the Type, not methods that were simply inherited.

See System.Reflection.BindingFlags for more information.

Note:
You cannot omit parameters when looking up constructors and methods. You can only omit parameters when invoking.

If the current T:System.Type represents a constructed generic type, this method returns the MethodInfo with the type parameters replaced by the appropriate type arguments.

If the current Type represents a type parameter in the definition of a generic type or generic method, this method searches the methods of the class constraint, or the methods of Object if there is no class constraint.

Note:
For generic methods, do not include the type arguments in name. For example, the C# code GetMember("MyMethod<int>") searches for a member with the text name "MyMethod<int>", rather than for a method named MyMethod that has one generic argument of type int.

Examples

The following example finds specific overloads of MethodA, specifying binding constraints, calling conventions, and a variety of argument types.

Note:
To run this example, see Building Examples That Use a Demo Method and a TextBlock Control.

Imports System.Reflection
Imports System.Runtime.InteropServices

Class Example

   ' Methods to get:

   Public Overloads Sub MethodA(ByVal i As Integer, ByVal l As Long)

   End Sub

   Public Overloads Sub MethodA(ByVal i() As Integer)

   End Sub

   Public Overloads Sub MethodA(ByRef r As Integer)

   End Sub

   ' Method that takes an integer and an out parameter. Note that an
   ' Imports reference is needed to System.Runtime.InteropServices
   ' for the <OutAttribute>, which can be shortened to <Out>.
   Public Overloads Sub MethodA(ByVal i As Integer, <Out()> ByRef o As Integer)
      o = 100
   End Sub

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

      ' Get MethodA(ByVal i As Integer, ByVal l As Long)
      mInfo = GetType(Example).GetMethod("MethodA", _
          BindingFlags.Public Or BindingFlags.Instance, _
          Nothing, _
          CallingConventions.Any, _
          New Type() {GetType(System.Int32), _
          GetType(System.Int64)}, _
          Nothing)
      outputBlock.Text += String.Format("Found method: {0}", mInfo) & vbCrLf

      ' Get  MethodA(ByVal i() As Integer)
      mInfo = GetType(Example).GetMethod("MethodA", _
          BindingFlags.Public Or BindingFlags.Instance, _
          Nothing, _
          CallingConventions.Any, _
          New Type() {GetType(System.Int32())}, _
          Nothing)
      outputBlock.Text += String.Format("Found method: {0}", mInfo) & vbCrLf

      ' Get MethodA(ByRef r As Integer)
      mInfo = GetType(Example).GetMethod("MethodA", _
      BindingFlags.Public Or BindingFlags.Instance, _
      Nothing, _
      CallingConventions.Any, _
      New Type() {GetType(System.Int32).MakeByRefType}, _
      Nothing)
      outputBlock.Text += String.Format("Found method: {0}", mInfo) & vbCrLf

      ' Get MethodA(ByVal i As Integer, <Out()> ByRef o As Integer)
      mInfo = GetType(Example).GetMethod("MethodA", _
      BindingFlags.Public Or BindingFlags.Instance, _
      Nothing, _
      CallingConventions.Any, _
      New Type() {GetType(System.Int32), GetType(System.Int32).MakeByRefType}, _
      Nothing)
      outputBlock.Text += String.Format("Found method: {0}", mInfo) & vbCrLf

   End Sub
End Class

' This method produces the following output:
'
'Found method: Void MethodA(Int32, Int32)
'Found method: Void MethodA(Int32[])
'Found method: Void MethodA(Int32 ByRef)
'Found method: Void MethodA(Int32, Int32 ByRef)

using System;
using System.Reflection;

class Example
{
   // Methods to get:

   public void MethodA(int i, int j) { }

   public void MethodA(int[] i) { }

   public void MethodA(ref int r) { }

   // Method that takes an out parameter:
   public void MethodA(int i, out int o) { o = 100; }


   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      MethodInfo mInfo;

      // Get MethodA(int i, int j)
      mInfo = typeof(Example).GetMethod("MethodA",
          BindingFlags.Public | BindingFlags.Instance,
          null,
          CallingConventions.Any,
          new Type[] { typeof(int), typeof(int) },
          null);
      outputBlock.Text += String.Format("Found method: {0}", mInfo) + "\n";

      // Get MethodA(int[] i)
      mInfo = typeof(Example).GetMethod("MethodA",
          BindingFlags.Public | BindingFlags.Instance,
          null,
          CallingConventions.Any,
          new Type[] { typeof(int[]) },
          null);
      outputBlock.Text += String.Format("Found method: {0}", mInfo) + "\n";

      // Get MethodA(ref int r)
      mInfo = typeof(Example).GetMethod("MethodA",
          BindingFlags.Public | BindingFlags.Instance,
          null,
          CallingConventions.Any,
          new Type[] { typeof(int).MakeByRefType() },
          null);
      outputBlock.Text += String.Format("Found method: {0}", mInfo) + "\n";

      // Get MethodA(int i, out int o)
      mInfo = typeof(Example).GetMethod("MethodA",
          BindingFlags.Public | BindingFlags.Instance,
          null,
          CallingConventions.Any,
          new Type[] { typeof(int), typeof(int).MakeByRefType() },
          null);
      outputBlock.Text += String.Format("Found method: {0}", mInfo) + "\n";

   }
}

/* This method produces the following output:

Found method: Void MethodA(Int32, Int32)
Found method: Void MethodA(Int32[])
Found method: Void MethodA(Int32 ByRef)
Found method: Void MethodA(Int32, Int32 ByRef)
  */

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

See Also

Reference

Type Class

GetMethod Overload

System Namespace

MethodInfo

String

BindingFlags

Binder

DefaultBinder

CallingConventions

ParameterModifier

GetMethodImpl

GetMethods