Open an existing map

Question

I'm trying to open a map located in a project folder, however when i try using this code i get Exception Unhandled error System.NullReferenceException: 'Object reference not set to an instance of an object.' mapProjectItem was null. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using ArcGIS.Core.CIM; using ArcGIS.Core.Data; using ArcGIS.Core.Geometry; using ArcGIS.Desktop.Catalog; using ArcGIS.Desktop.Core; using ArcGIS.Desktop.Editing; using ArcGIS.Desktop.Extensions; using ArcGIS.Desktop.Framework; using ArcGIS.Desktop.Framework.Contracts; using ArcGIS.Desktop.Framework.Dialogs; using ArcGIS.Desktop.Framework.Threading.Tasks; using ArcGIS.Desktop.Mapping; namespace AddData { internal class Button4 : Button { protected override void OnClick() { { var mapProjectItems = Project.Current.GetItems<MapProjectItem>(); var mapProjectItem = mapProjectItems.FirstOrDefault(mpi => mpi.Name.Equals("Map1")); Map map = mapProjectItem.GetMap(); ProApp.Panes.CreateMapPaneAsync(map); } } } }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Exception Unhandled.PNG

UmaHarano · Accepted Answer

Hi It would be a good idea to check the map project item exists to be safe. Also, you will have to wrap this code within the context of a QueuedTask.Run. Like this: protected override void OnClick() { QueuedTask.Run( () => { var mapProjectItems = Project.Current.GetItems<MapProjectItem>(); var mapProjectItem = mapProjectItems.FirstOrDefault(mpi => mpi.Name.Equals("Map1")); Map map = mapProjectItem?.GetMap(); //Check if mapProjectItem exists. ProApp.Panes.CreateMapPaneAsync(map); }); }‍‍‍‍‍‍‍‍‍‍