Tutorial Error: Creator Kit - Beginner Code

Hi Unity,

When I am following your "Creator Kit - Beginner Code" tutorial at https://learn.unity.com/tutorial/customize-the-health-potions. In step 2, I have encountered the following problem:

When I follow Beginner Code > Create Item Effect > Enter a name without spaces (e.g., “AddHealthEffect”) and select Create. I can't create the name, there is no response, instead, I get the following error:

NullReferenceException: Object reference not set to an instance of an object
NameWindow.OnGUI () (at Assets/Creator Kit - Beginner Code/Scripts/Editor/CreateScriptEditor.cs:178)

I am using Unity 2019.3.14f1.
It seems some other users also encounter the same problem.

Many Thanks,
Elijah

 

Here is the code of "CreateScriptEditor.cs"

using System.IO;
using UnityEngine;
using UnityEditor;
using System.CodeDom.Compiler;

public class CreateScriptEditor
{
[MenuItem("Beginner Code/Create Item Effect")]
static void CreateItemEffect()
{
var win = EditorWindow.GetWindow<NameWindow>();
win.Display();

win.OnValidate = s =>
{
string[] asset = AssetDatabase.FindAssets("SampleItemEffect");

if (asset.Length > 0)
{
var textAsset = AssetDatabase.LoadAssetAtPath<TextAsset>(AssetDatabase.GUIDToAssetPath(asset[0]));

string result = textAsset.text.Replace("{EFFECTNAME}", s);

string targetPath = Application.dataPath + "/Scripts/ItemEffect/";
Directory.CreateDirectory(targetPath);

targetPath += s + ".cs";
File.WriteAllText(targetPath, result);
AssetDatabase.Refresh();

Selection.activeObject = AssetDatabase.LoadMainAssetAtPath(targetPath.Replace(Application.dataPath, "Assets"));
EditorWindow.GetWindow(System.Type.GetType("UnityEditor.ProjectBrowser, UnityEditor"));
EditorGUIUtility.PingObject(Selection.activeObject);
}
else
{
Debug.LogError("Couldn't find the sample item effect script file");
}
};
}

[MenuItem("Beginner Code/Create Weapon Attack Effect")]
static void CreateWeaponEffect()
{
var win = EditorWindow.GetWindow<NameWindow>();
win.Display();

win.OnValidate = s =>
{
string[] asset = AssetDatabase.FindAssets("SampleWeaponEffect");

if (asset.Length > 0)
{
var textAsset = AssetDatabase.LoadAssetAtPath<TextAsset>(AssetDatabase.GUIDToAssetPath(asset[0]));

string result = textAsset.text.Replace("{EFFECTNAME}", s);

string targetPath = Application.dataPath + "/Scripts/WeaponEffect/";
Directory.CreateDirectory(targetPath);

targetPath += s + ".cs";
File.WriteAllText(targetPath, result);
AssetDatabase.Refresh();

Selection.activeObject = AssetDatabase.LoadMainAssetAtPath(targetPath.Replace(Application.dataPath, "Assets"));
EditorWindow.GetWindow(System.Type.GetType("UnityEditor.ProjectBrowser, UnityEditor"));
EditorGUIUtility.PingObject(Selection.activeObject);
}
else
{
Debug.LogError("Couldn't find the sample weapon effect script file");
}
};
}

[MenuItem("Beginner Code/Create Equipped Effect")]
static void CreateEquippedEffect()
{
var win = EditorWindow.GetWindow<NameWindow>();
win.Display();

win.OnValidate = s =>
{
string[] asset = AssetDatabase.FindAssets("SampleEquipmentEffect");

if (asset.Length > 0)
{
var textAsset = AssetDatabase.LoadAssetAtPath<TextAsset>(AssetDatabase.GUIDToAssetPath(asset[0]));

string result = textAsset.text.Replace("{EFFECTNAME}", s);

string targetPath = Application.dataPath + "/Scripts/EquippedEffect/";
Directory.CreateDirectory(targetPath);

targetPath += s + ".cs";
File.WriteAllText(targetPath, result);
AssetDatabase.Refresh();

Selection.activeObject = AssetDatabase.LoadMainAssetAtPath(targetPath.Replace(Application.dataPath, "Assets"));
EditorWindow.GetWindow(System.Type.GetType("UnityEditor.ProjectBrowser, UnityEditor"));
EditorGUIUtility.PingObject(Selection.activeObject);
}
else
{
Debug.LogError("Couldn't find the sample equipped effect script file");
}
};
}

[MenuItem("Beginner Code/Create Interactable Object")]
static void CreateInteractableObject()
{
var win = EditorWindow.GetWindow<NameWindow>();
win.Display();

win.OnValidate = s =>
{
string[] asset = AssetDatabase.FindAssets("SampleInteractableObject");

if (asset.Length > 0)
{
var textAsset = AssetDatabase.LoadAssetAtPath<TextAsset>(AssetDatabase.GUIDToAssetPath(asset[0]));

string result = textAsset.text.Replace("{EFFECTNAME}", s);

string targetPath = Application.dataPath + "/Scripts/InteractableObjects/";
Directory.CreateDirectory(targetPath);

targetPath += s + ".cs";
File.WriteAllText(targetPath, result);
AssetDatabase.Refresh();

Selection.activeObject = AssetDatabase.LoadMainAssetAtPath(targetPath.Replace(Application.dataPath, "Assets"));
EditorWindow.GetWindow(System.Type.GetType("UnityEditor.ProjectBrowser, UnityEditor"));
EditorGUIUtility.PingObject(Selection.activeObject);
}
else
{
Debug.LogError("Couldn't find the sample interactable script file");
}
};
}
}

public class NameWindow : EditorWindow
{
public System.Action<string> OnValidate;

string m_EffectName;

CodeDomProvider _provider;

public void Display()
{
var pos = position;
pos.size = new Vector2(400, 300);
position = pos;

m_EffectName = "";

if (_provider == null)
_provider = CodeDomProvider.CreateProvider("CSharp");

ShowModalUtility();
}

void OnGUI()
{
m_EffectName = EditorGUILayout.TextField("Effect Name", m_EffectName);

bool validName = _provider.IsValidIdentifier(m_EffectName);

EditorGUILayout.BeginHorizontal();

GUI.enabled = validName;
if (GUILayout.Button(validName ? "Create" : "Invalid Name"))
{
OnValidate(m_EffectName);
Close();
}

GUI.enabled = true;
if (GUILayout.Button("Cancel"))
{
Close();
}

EditorGUILayout.EndHorizontal();

if (!validName)
{
EditorGUILayout.HelpBox("The name is not valid. It shouldn't contains space, start with a number or contains special character like ; or .", MessageType.Error);
}
}
}

 

This is relevant to getting help: How to report problems correctly in the Unity3D forums:

http://plbm.com/?p=220

ALSO, this is how to fix a NullReferenceException in Unity3D:

http://plbm.com/?p=221

 

I had the same problem. I had to move the win.Display() after the win.OnValidate definition in CreateScriptEditor.cs. I did this for each of the Create* menu items since they probably all had the same issue.

Code (CSharp):

1.     static void CreateItemEffect()
2.     {
3.         var win = EditorWindow.GetWindow<NameWindow>();
4.  
5.         win.OnValidate = s =>
6.         {
7.             ...
8.         }
9.  
10.         win.Display();
11.     }

 

While I was following the tutorial, I suddenly realised that 21 errors appeared. All of these errors had something to do with different scripts. I tried everything I know of, including undoing what I did and restoring. I will post the code here. Can someone please help me?

 

It's always best to start a fresh post rather than hijacking some random half-a-year-old post.

Make your own post please, it's free. And when you do, since none of us are mind readers and cannot imagine what your 21 errors are, follow this simple guideline:

Please use code tags: https://forum.unity.com/threads/using-code-tags-properly.143875/

How to report problems productively in the Unity3D forums:

http://plbm.com/?p=220

Help us to help you.

 

sorry, I will do so now