ArcGIS - ICommandBars exception

Question

Testing my VB.NET 2010 app in ArcMap an exception occurs when ICommandBars is instantiated.

' zoom to selected
Dim mxApp As ESRI.ArcGIS.Framework.IApplication
Dim numUID As UID = New ESRI.ArcGIS.esriSystem.UID
numUID.Value = "{AB073B49-DE5E-11D1-AA80-00C04FA37860}"
Dim commandBars As ICommandBars = mxApp.Document.CommandBars   '>>> error here!!!!!!!!
Dim cmdItem As ICommandItem = CommandBars.Find(numUID, False, False)
If Not (cmdItem Is Nothing) Then
    cmdItem.Execute()
End If

Message: Exception first-chance type 'System.NullReferenceException' in LUCAS.dll.

P.S. ArcGIS 10 SP1 on Windows 7, VS2010.

Answer 1

You've declared mxApp, but you haven't actually set it to anything. If you're using an addin, you can set that with the line

mxApp = My.ArcMap.Application