Beamer.cs

using UnityEngine;
using System;
using System.Collections.Generic;

namespace BelacCorp
{
    [KSPAddon(KSPAddon.Startup.SpaceCentre, true)]
    public class BeamActionTracker : MonoBehaviour
    {
        public class BeamAction
        {
            private Part toBeamer = null;
            public virtual Part ToBeamer { get { return this.toBeamer; } }
            private ProtoCrewMember kerbal = null;
            public virtual ProtoCrewMember Kerbal { get { return this.kerbal; } }

            public BeamAction(Part toBeamer, ProtoCrewMember kerbal)
            {
                this.toBeamer = toBeamer;
                this.kerbal = kerbal;
            }
        }

        public static BeamAction currentBeamAction = null;
        public static bool doBeam = false;
        public static double crewBeamedTime;
        public const double crewBeamDelay = 0.25;

        public void Start()
        {
            Debug.Log("[BelacCorp]Setting Up event");
            DontDestroyOnLoad(this);
            GameEvents.onFlightReady.Add(CheckForBeamAction);
        }

        public void CheckForBeamAction()
        {
            Debug.Log("[BelacCorp]CheckForBeamAction called");
            if (BeamActionTracker.doBeam == true)
            {
                Debug.Log("[BelacCorp]currentBeamAction != null");
                if (FlightGlobals.ActiveVessel.id == BeamActionTracker.currentBeamAction.ToBeamer.vessel.id)
                {
                    Debug.Log("[BelacCorp]vessel.ids match");
                    GameEvents.onPartUnpack.Add(PutCrewInBeamer);
                }
            }
        }

        public void PutCrewInBeamer(Part part)
        {
            Debug.Log("[BelacCorp]PutCrewInBeamer called");
            if (BeamActionTracker.currentBeamAction.ToBeamer.flightID == part.flightID)
            {
                Debug.Log("[BelacCorp]part.flightIDs match");
                GameEvents.onPartUnpack.Remove(PutCrewInBeamer);
                part.Unpack();
                Debug.Log("[BelacCorp]part.Unpack() called, adding" + BeamActionTracker.currentBeamAction.Kerbal.name);
                BeamActionTracker.currentBeamAction.ToBeamer.AddCrewmember(BeamActionTracker.currentBeamAction.Kerbal);
                crewBeamedTime = Planetarium.GetUniversalTime();
                BeamActionTracker.doBeam = false;
            }
        }
    }

    public class Beamer : PartModule
    {
        private Rect windowPos;
        private bool windowIsActive = false;

        private class ValidBeamerGUIInfo
        {
            public Part beamer;
            public string vesselName;

            public ValidBeamerGUIInfo(Part part, string name)
            {
                this.beamer = part;
                this.vesselName = name;
            }
        }

        private List<ValidBeamerGUIInfo> ValidBeamerList = new List<ValidBeamerGUIInfo>();

		private void WindowGUI(int windowID)
		{
        	GUIStyle mySty = new GUIStyle(GUI.skin.button); 
       		mySty.normal.textColor = mySty.focused.textColor = Color.white;
      		mySty.hover.textColor = mySty.active.textColor = Color.yellow;
      		mySty.onNormal.textColor = mySty.onFocused.textColor = mySty.onHover.textColor = mySty.onActive.textColor = Color.green;
      		mySty.padding = new RectOffset(8, 8, 8, 8);
 
            GUILayout.BeginVertical();
            GUILayout.Label("Note: Vessel Type must be a \"Ship\" for it to appear in this list.", mySty, GUILayout.MinHeight(20));
            if(this.part.protoModuleCrew.Count == 1)
            {
               if(this.ValidBeamerList.Count > 0)
               {
                   this.ValidBeamerList.ForEach(delegate(ValidBeamerGUIInfo beamerInfo)
                    {

                        if (beamerInfo.beamer.protoModuleCrew.Count == 0)
                        {
                            if (GUILayout.Button("Beam to " + beamerInfo.vesselName, mySty, GUILayout.ExpandWidth(true)))
                            {
                                this.BeamKerbal(this.part, beamerInfo.beamer);
                            }
                        }
                        else
                        {
                            GUILayout.Label(beamerInfo.vesselName + " beamer is not emtpy!", mySty, GUILayout.MinHeight(20));
                        }
                   });
                }
                else
                {
                    GUILayout.Label("No Oher Vessesls With a Beamer in Range", mySty, GUILayout.MinHeight(20));
                }
            }
            else
            {
                GUILayout.Label("No Kerbals In Cabin To Beam", mySty, GUILayout.MinHeight(20));
            }

            if (GUILayout.Button("Close Window", mySty, GUILayout.ExpandWidth(true)))
            {
                RenderingManager.RemoveFromPostDrawQueue(3, new Callback(drawGUI));
                windowIsActive = false;
            }

		    GUILayout.EndVertical();
            GUI.DragWindow(new Rect(0, 0, 10000, 20));
 
		}

        private void BeamKerbal(Part FromBeamer, Part ToBeamer)
        {
            //only holds one kerbal
            var kerbal = FromBeamer.protoModuleCrew[0];

            BeamActionTracker.currentBeamAction = new BeamActionTracker.BeamAction(ToBeamer, kerbal);

            FromBeamer.RemoveCrewmember(kerbal);
            RenderingManager.RemoveFromPostDrawQueue(3, new Callback(drawGUI));
            windowIsActive = false;

            if (ToBeamer.vessel.loaded)
            {
                BeamActionTracker.currentBeamAction.ToBeamer.AddCrewmember(BeamActionTracker.currentBeamAction.Kerbal);
                BeamActionTracker.crewBeamedTime = Planetarium.GetUniversalTime();
                BeamActionTracker.doBeam = false;
            }
            
            FlightGlobals.SetActiveVessel(ToBeamer.vessel);
        }

       

		private void drawGUI()
		{
            if ((this.windowPos.x == 0) && (this.windowPos.y == 0))
            {
                this.windowPos = new Rect(Screen.width / 2, Screen.height / 2, 10, 10);
            }
            GUI.skin = HighLogic.Skin;
            this.windowPos = GUILayout.Window(1, this.windowPos, WindowGUI, "Beam Kerbal", GUILayout.MinWidth(400));	 
		}
       
        [KSPEvent(guiActive=true,guiName="Beam Kerbal",active=true,guiActiveEditor=false)]
        private void ShowBeamWindow()
        {
            if(!this.windowIsActive){
                this.ValidBeamerList.Clear();
                if (this.part.protoModuleCrew.Count == 1)
                {
                    FlightGlobals.Vessels.ForEach(delegate(Vessel vessel)
                    {
                        if (vessel != this.part.vessel && vessel.vesselType == VesselType.Ship)
                        {
                            print("[BelacCorp]checking "+vessel.vesselName);
                           
                            if (!vessel.loaded)
                            {
                                print("[BelacCorp]loading "+vessel.vesselName);
                                vessel.Load();
                            }
                           
                            print("[BelacCorp]checking "+vessel.parts.Count+" "+vessel.vesselName+" parts");
                            vessel.parts.ForEach(delegate(Part vesselPart)
                            {
                                //print("[BelacCorp]checking part " + vesselPart.partInfo.name+" == "+this.part.partInfo.name);
                                if (vesselPart.partInfo.name == this.part.partInfo.name &&
                                    this.part.vessel.mainBody == vessel.mainBody)
                                {
                                    this.ValidBeamerList.Add(new ValidBeamerGUIInfo(vesselPart, vessel.vesselName));
                                }
                            });
                        }
                    });
                }
                windowIsActive = true;
                RenderingManager.AddToPostDrawQueue(3,new Callback(drawGUI));
            }
        }
        
        public override void OnUpdate()
        {
            if (BeamActionTracker.crewBeamedTime != 0)
            {
                if (Planetarium.GetUniversalTime() - BeamActionTracker.crewBeamedTime >= BeamActionTracker.crewBeamDelay)
                {
                    FlightGlobals.ActiveVessel.SpawnCrew();
                    BeamActionTracker.crewBeamedTime = 0;
                }
            }
            base.OnUpdate();
        }
    }
}

If you click the "Beam Kerbal" button, then close the window, and click it again, you get:

[BelacCorp]checking Beamer2
[LOG 19:01:15.622] [BelacCorp]loading Beamer2
[WRN 19:01:15.631] HighlightingSystem : Multiple Highlighter components on a single GameObject is not allowed! Highlighter has been disabled on a GameObject with name 'model'.
[WRN 19:01:15.635] ...FlagDecal module found at index 0.
[WRN 19:01:15.636] PartModule is null.

Also, doing a beam to a vessel out of range only removes the kerbal, but never puts them into the switched to vessel.