ParameterInfo.IsOut Property

Definition

Namespace:

System.Reflection

Assembly:

System.Runtime.dll

Source:

ParameterInfo.cs

Gets a value indicating whether this is an output parameter.

public:
 property bool IsOut { bool get(); };

public bool IsOut { get; }

member this.IsOut : bool

Public ReadOnly Property IsOut As Boolean

Property Value

Boolean

true if the parameter is an output parameter; otherwise, false.

Examples

The following example shows how to test method parameters for the ParameterAttributes.In, ParameterAttributes.Out, and ParameterAttributes.Optional attributes.

The example contains a DefineMethod method that does the following:

• Creates a dynamic assembly containing a MyType type.

• Adds a MyMethod method to MyType. MyMethod has three parameters. The first parameter is defined with ParameterAttributes.In, the second with ParameterAttributes.Out, and the third with ParameterAttributes.Optional.

• Calls TypeBuilder.CreateType to complete the type.

After executing DefineMethod, the example searches the assemblies that are currently loaded until it finds the dynamic assembly. It loads MyType from the assembly, gets a MethodInfo object for the MyMethod method, and examines the parameters. The example uses the IsIn, IsOut, and IsOptional properties to display information about the parameters.

using namespace System;
using namespace System::Reflection;
using namespace System::Runtime::InteropServices;
public ref class parminfo
{
public:
   static void mymethod( int int1m, [Out]interior_ptr<String^> str2m, interior_ptr<String^> str3m )
   {
       *str2m = "in mymethod";
   }

};

int main()
{
   Console::WriteLine( "\nReflection.Parameterinfo" );
   
   //Get the ParameterInfo parameter of a function.
   //Get the type.
   Type^ Mytype = Type::GetType( "parminfo" );
   
   //Get and display the method.
   MethodBase^ Mymethodbase = Mytype->GetMethod( "mymethod" );
   Console::Write( "\nMymethodbase = {0}", Mymethodbase );
   
   //Get the ParameterInfo array.
   array<ParameterInfo^>^Myarray = Mymethodbase->GetParameters();
   
   //Get and display the IsOut of each parameter.
   System::Collections::IEnumerator^ enum0 = Myarray->GetEnumerator();
   while ( enum0->MoveNext() )
   {
      ParameterInfo^ Myparam = safe_cast<ParameterInfo^>(enum0->Current);
      Console::Write( "\nFor parameter # {0}, the IsOut is - {1}", Myparam->Position, Myparam->IsOut );
   }

   return 0;
}

/*
This code produces the following output:

Reflection.ParameterInfo

Mymethodbase = Void mymethod (Int32, System.String ByRef, System.String ByRef)
For parameter # 0, the IsOut is - False
For parameter # 1, the IsOut is - True
For parameter # 2, the IsOut is - False
*/

using System;
using System.Reflection;

 class parminfo
 {
    public static void mymethod (
       int int1m, out string str2m, ref string str3m)
    {
       str2m = "in mymethod";
    }

    public static int Main(string[] args)
    {
       Console.WriteLine("\nReflection.Parameterinfo");

       //Get the ParameterInfo parameter of a function.

       //Get the type.
       Type Mytype = Type.GetType("parminfo");

       //Get and display the method.
       MethodBase Mymethodbase = Mytype.GetMethod("mymethod");
       Console.Write("\nMymethodbase = " + Mymethodbase);

       //Get the ParameterInfo array.
       ParameterInfo[] Myarray = Mymethodbase.GetParameters();

       //Get and display the IsOut of each parameter.
       foreach (ParameterInfo Myparam in Myarray)
       {
          Console.Write ("\nFor parameter # "   + Myparam.Position
             + ", the IsOut is - " +  Myparam.IsOut );
       }
       return 0;
    }
 }
 /*
 This code produces the following output:

 Reflection.ParameterInfo

 Mymethodbase = Void mymethod (int, System.String ByRef, System.String ByRef)
 For parameter # 0, the IsOut is - False
 For parameter # 1, the IsOut is - True
 For parameter # 2, the IsOut is - False
 */

Imports System.Reflection

Class parminfo
    
    Public Shared Sub mymethod(int1m As Integer, ByRef str2m As String, _
    ByRef str3m As String)    
        str2m = "in mymethod"
    End Sub
    
    Public Shared Function Main() As Integer
        Console.WriteLine(ControlChars.CrLf + "Reflection.Parameterinfo")
        
        'Get the ParameterInfo parameter of a function.
        'Get the type.
        Dim Mytype As Type = Type.GetType("parminfo")
        
        'Get and display the method.
        Dim Mymethodbase As MethodBase = Mytype.GetMethod("mymethod")
        Console.Write(ControlChars.CrLf + "Mymethodbase = " _
           + Mymethodbase.ToString())
        
        'Get the ParameterInfo array.
        Dim Myarray As ParameterInfo() = Mymethodbase.GetParameters()
        
        'Get and display the IsOut of each parameter.
        Dim Myparam As ParameterInfo
        For Each Myparam In  Myarray
            Console.Write(ControlChars.CrLf _
               + "For parameter # " + Myparam.Position.ToString() _
               + ", the IsOut is - " + Myparam.IsOut.ToString())
        Next Myparam
        Return 0
    End Function
End Class

' This code produces the following output:
'
' Reflection.ParameterInfo
'  
' Mymethodbase = Void mymethod (Int32, System.String ByRef, System.String ByRef)
' For parameter # 0, the IsOut is - False
' For parameter # 1, the IsOut is - True
' For parameter # 2, the IsOut is - False

Remarks

This method depends on an optional metadata flag. This flag can be inserted by compilers, but the compilers are not obligated to do so.

This method utilizes the Out flag of the ParameterAttributes enumerator.

To get the ParameterInfo array, first get the method or the constructor and then call MethodBase.GetParameters.