ArcObjects C#

[martywalters]

I'm coverting Hussein Nasser VB code to C# but I'm having problems.

it's from his session:

Extending ArcObjects with .NET (IGeometry) - 02 - Working with Layers

The Vb code works but my converted C# crashes

here is my onclick code from form1 : Form

ERROR ->

System.NullReferenceException: Object reference not set to an instance of

OCCURS during the Assignment of pMap.

        private void button1_Click(object sender, EventArgs e)

        {

            IMxDocument pMxDoc = (IMxDocument)_application.Document;

            IMap pMap = pMxDoc.FocusMap;

        }

vb code : 

Private _application As IApplication

    Public Property ArcMapApplication() As IApplication

        Get

            Return _application

        End Get

        Set(ByVal value As IApplication)

            _application = value

        End Set

    End Property

c# code:

        private IApplication _application;

        public IApplication ArcMapApplication

        {

            get { return _application; }

            set { _application = value; }

        }

[martywalters · Accepted solution]

Hussein Nasser himself solved it for me

Hussein, thanks for the Great Video series on Extending ArcObjects.

Double Thanks for providing me help.

[OwenEarley]

In what context are you running this code? - for example within an Add-In, old style COM extension, etc.

Has your _application object already been set or is it null?

EDIT - I got side-tracked and should have refreshed before posting to see if an answer had already been posted