Type.GetMethod Method (String, BindingFlags)

 

Searches for the specified method, using the specified binding constraints.

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

public MethodInfo GetMethod(
	string name,
	BindingFlags bindingAttr
)

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 null.

Return Value

Type: System.Reflection.MethodInfo

An object representing the method that matches the specified requirements, if found; otherwise, null.

Exception Condition
AmbiguousMatchException

More than one method is found with the specified name and matching the specified binding constraints.

ArgumentNullException

name is null.

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

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

See System.Reflection.BindingFlags for more information.

If a method is overloaded and more than one overload meets the constraints specified by the bindingAttr argument, the method throws an AmbiguousMatchException exception. In the following example, an exception is thrown because:

  • The TestClass type has two public instance overloads of the DisplayValue method, DisplayValue(String) and DisplayValue(String, Object[]).

  • The TestClass type has two public instance overloads of the Equals method, one of which is inherited from Object: Equals(TestClass) and Equals(Object).

using System;
using System.Reflection;

public class TestClass
{
   public void DisplayValue(String s)
   {
      Console.WriteLine(s);
   }

   public void DisplayValue(String s, params Object[] values)
   {
      Console.WriteLine(s, values);
   }

   public static bool Equals(TestClass t1, TestClass t2)
   {
      return Object.ReferenceEquals(t1, t2);
   }

   public bool Equals(TestClass t) 
   {
      return Object.ReferenceEquals(this, t);
   }          
}

public class Example
{
   public static void Main()
   {
      Type t = typeof(TestClass);

      RetrieveMethod(t, "DisplayValue", BindingFlags.Public | BindingFlags.Instance);

      RetrieveMethod(t, "Equals", BindingFlags.Public | BindingFlags.Instance);

      RetrieveMethod(t, "Equals", BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly);

      RetrieveMethod(t, "Equals", BindingFlags.Public | BindingFlags.Static);
   }

   private static void RetrieveMethod(Type t, String name, BindingFlags flags)
   {
      try {
         MethodInfo m = t.GetMethod(name, flags);
         if (m != null) {
            Console.Write("{0}.{1}(", t.Name, m.Name);
            ParameterInfo[] parms= m.GetParameters();
            for (int ctr = 0; ctr <parms.Length; ctr++) {
               Console.Write(parms[ctr].ParameterType.Name);
               if (ctr < parms.Length - 1) 
                  Console.Write(", ");

            }
            Console.WriteLine(")");
         }
         else {
            Console.WriteLine("Method not found");
         }
      }
      catch (AmbiguousMatchException) {
         Console.WriteLine("The following duplicate matches were found:");
         MethodInfo[] methods = t.GetMethods(flags);
         foreach (var method in methods) {
            if (method.Name != name) continue;

            Console.Write("   {0}.{1}(", t.Name, method.Name);
            ParameterInfo[] parms = method.GetParameters();
            for (int ctr = 0; ctr < parms.Length; ctr++) {
               Console.Write(parms[ctr].ParameterType.Name);
               if (ctr < parms.Length - 1) 
                  Console.Write(", ");

            }
            Console.WriteLine(")");
         } 
      }         
      Console.WriteLine();
   }
}
// The example displays the following output:
//       The following duplicate matches were found:
//          TestClass.DisplayValue(String)
//          TestClass.DisplayValue(String, Object[])
//       
//       The following duplicate matches were found:
//          TestClass.Equals(TestClass)
//          TestClass.Equals(Object)
//       
//       TestClass.Equals(TestClass)
//       
//       TestClass.Equals(TestClass, TestClass)

You can do one of the following to retrieve a specific method:

  • Change the binding constraints. In the previous example, attempting to retrieve a public instance Equals method that is declared by the type and not inherited successfully retrieves Equals(TestClass).

  • Call an overload of the GetMethod method that includes a types parameter which defines the types of the method's parameters.

  • Call the GetMethods(BindingFlags) method to retrieve an array containing all of the methods belonging to a type that have the specified binding attributes. You can then iterate it to identify the duplicate methods named name. This approach is illustrated in the previous example's handler for the AmbiguousMatchException exception.

If the current 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.

System_CAPS_noteNote

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.

The following example gets the method that matches the specified binding flags.


using System;
using System.Reflection;

class Program
{

    // Method to get:
    public void MethodA() { }


    static void Main(string[] args)
    {

        // Get MethodA()
        MethodInfo mInfo = typeof(Program).GetMethod("MethodA",
            BindingFlags.Public | BindingFlags.Instance);
        Console.WriteLine("Found method: {0}", mInfo);

    }
}

.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
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