The type or namespace name `UnityEditor' could not be found

Question

Pls help me correct this problem.

Assets/Menu.cs(97,73): warning CS0618: UnityEditor.EditorUtility.GetAssetPath(UnityEngine.Object)' is obsolete:Use AssetDatabase.GetAssetPath'

Error building Player because scripts had compiler errors

Assets/Menu.cs(2,7): error CS0246: The type or namespace name `UnityEditor' could not be found. Are you missing a using directive or an assembly reference?

using UnityEngine;
using UnityEditor;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System;
using System.Linq;

struct ObjMaterial
{
    public string name;
    public string textureName;
}

public class Menu : MonoBehaviour { 

    public int window; 

    void Start () { 
        window = 1;

    } 

    private static int vertexOffset = 0;
    private static int normalOffset = 0;
    private static int uvOffset = 0;


    //User should probably be able to change this. It is currently left as an excercise for
    //the reader.
    private static string targetFolder = "ExportedObj";


    private static string MeshToString(Component mf, Dictionary<string, ObjMaterial> materialList) 
    {



        Mesh m;
        Material[] mats;

        if(mf is MeshFilter)
        {
            m = (mf as MeshFilter).mesh;
            mats = mf.GetComponent<Renderer>().sharedMaterials;
        }
        else if(mf is SkinnedMeshRenderer)
        {
            m = (mf as SkinnedMeshRenderer).sharedMesh;
            mats = (mf as SkinnedMeshRenderer).sharedMaterials;
        }
        else
        {
            return "";
        }

        StringBuilder sb = new StringBuilder();

        sb.Append("g ").Append(mf.name).Append("\n");
        foreach(Vector3 lv in m.vertices) 
        {
            Vector3 wv = mf.transform.TransformPoint(lv);

            //This is sort of ugly - inverting x-component since we're in
            //a different coordinate system than "everyone" is "used to".
            sb.Append(string.Format("v {0} {1} {2}\n",-wv.x,wv.y,wv.z));
        }
        sb.Append("\n");

        foreach(Vector3 lv in m.normals) 
        {
            Vector3 wv = mf.transform.TransformDirection(lv);

            sb.Append(string.Format("vn {0} {1} {2}\n",-wv.x,wv.y,wv.z));
        }
        sb.Append("\n");

        foreach(Vector3 v in m.uv) 
        {
            sb.Append(string.Format("vt {0} {1}\n",v.x,v.y));
        }

        for (int material=0; material < m.subMeshCount; material ++) {
            sb.Append("\n");
            sb.Append("usemtl ").Append(mats[material].name).Append("\n");
            sb.Append("usemap ").Append(mats[material].name).Append("\n");

            //See if this material is already in the materiallist.
            try
            {
                ObjMaterial objMaterial = new ObjMaterial();

                objMaterial.name = mats[material].name;


                objMaterial.textureName = EditorUtility.GetAssetPath(mats[material].mainTexture);
                //else 
                    //objMaterial.textureName = null;

                materialList.Add(objMaterial.name, objMaterial);
            }
            catch (ArgumentException)
            {
                //Already in the dictionary
            }


            int[] triangles = m.GetTriangles(material);
            for (int i=0;i<triangles.Length;i+=3) 
            {
                //Because we inverted the x-component, we also needed to alter the triangle winding.
                sb.Append(string.Format("f {1}/{1}/{1} {0}/{0}/{0} {2}/{2}/{2}\n", 
                    triangles[i]+1 + vertexOffset, triangles[i+1]+1 + normalOffset, triangles[i+2]+1 + uvOffset));
            }
        }

        vertexOffset += m.vertices.Length;
        normalOffset += m.normals.Length;
        uvOffset += m.uv.Length;

        return sb.ToString();
    }

    private static void Clear()
    {
        vertexOffset = 0;
        normalOffset = 0;
        uvOffset = 0;
    }

    private static Dictionary<string, ObjMaterial> PrepareFileWrite()
    {
        Clear();

        return new Dictionary<string, ObjMaterial>();
    }

    private static void MaterialsToFile(Dictionary<string, ObjMaterial> materialList, string folder, string filename)
    {
        using (StreamWriter sw = new StreamWriter(folder + "/" + filename + ".mtl")) 
        {
            foreach( KeyValuePair<string, ObjMaterial> kvp in materialList )
            {
                sw.Write("\n");
                sw.Write("newmtl {0}\n", kvp.Key);
                sw.Write("Ka  0.6 0.6 0.6\n");
                sw.Write("Kd  0.6 0.6 0.6\n");
                sw.Write("Ks  0.9 0.9 0.9\n");
                sw.Write("d  1.0\n");
                sw.Write("Ns  0.0\n");
                sw.Write("illum 2\n");

                if (kvp.Value.textureName != null)
                {
                    string destinationFile = kvp.Value.textureName;


                    int stripIndex = destinationFile.LastIndexOf('/');//FIXME: Should be Path.PathSeparator;

                    if (stripIndex >= 0)
                        destinationFile = destinationFile.Substring(stripIndex + 1).Trim();


                    string relativeFile = destinationFile;

                    destinationFile = folder + "/" + destinationFile;

                    Debug.Log("Copying texture from " + kvp.Value.textureName + " to " + destinationFile);

                    try
                    {
                        //Copy the source file
                        File.Copy(kvp.Value.textureName, destinationFile);
                    }
                    catch
                    {

                    }   


                    sw.Write("map_Kd {0}", relativeFile);
                }

                sw.Write("\n\n\n");
            }
        }
    }

    private static void MeshToFile(Component mf, string folder, string filename) 
    {
        Dictionary<string, ObjMaterial> materialList = PrepareFileWrite();

        using (StreamWriter sw = new StreamWriter(folder +"/" + filename + ".obj")) 
        {
            sw.Write("mtllib ./" + filename + ".mtl\n");

            sw.Write(MeshToString(mf, materialList));
        }

        MaterialsToFile(materialList, folder, filename);
    }

    private static void MeshesToFile(Component[] mf, string folder, string filename) 
    {
        Dictionary<string, ObjMaterial> materialList = PrepareFileWrite();

        using (StreamWriter sw = new StreamWriter(folder +"/" + filename + ".obj")) 
        {
            sw.Write("mtllib ./" + filename + ".mtl\n");

            for (int i = 0; i < mf.Length; i++)
            {
                sw.Write(MeshToString(mf[i], materialList));
            }
        }

        MaterialsToFile(materialList, folder, filename);
    }

    private static bool CreateTargetFolder()
    {
        try
        {
            System.IO.Directory.CreateDirectory(targetFolder);
        }
        catch
        {
            //EditorUtility.DisplayDialog("Error!", "Failed to create target folder!", "");
            return false;
        }

        return true;
    }



    void OnGUI () { 
        GUI.BeginGroup (new Rect (Screen.width / 2 - 100, Screen.height / 2 - 100, 200, 200)); 
        if(window == 1) 
        { 
            if(GUI.Button (new Rect (10,30,180,30), "Экспортировать")) 
            { 

                if (!CreateTargetFolder())
                    return;

                //GameObject[] gos = GameObject.FindGameObjectsWithTag("Boat");
                //Selection.objects = gos;

                GameObject[] selection = GameObject.FindGameObjectsWithTag("Boat");
                //Transform[] selection = Selection.GetTransforms(SelectionMode.Editable | SelectionMode.ExcludePrefab);

                if (selection.Length == 0)
                {
                    //EditorUtility.DisplayDialog("No source object selected!", "Please select one or more target objects", "");
                    return;
                }

                int exportedObjects = 0;

                ArrayList mfList = new ArrayList();

                for (int i = 0; i < selection.Length; i++)
                {
                    Component[] meshfilter = selection[i].GetComponentsInChildren(typeof(MeshFilter)).Concat(selection[i].GetComponentsInChildren(typeof(SkinnedMeshRenderer))).ToArray();

                    for (int m = 0; m < meshfilter.Length; m++)
                    {
                        exportedObjects++;
                        mfList.Add(meshfilter[m]);
                    }
                }

                if (exportedObjects > 0) 
                {
                    Component[] mf = new Component[mfList.Count];

                    for (int i = 0; i < mfList.Count; i++) {
                        mf [i] = (Component)mfList [i];
                    }

                    string filename = /*EditorApplication.currentScene +*/ "_" + exportedObjects;

                    int stripIndex = filename.LastIndexOf ('/');//FIXME: Should be Path.PathSeparator

                    if (stripIndex >= 0)
                        filename = filename.Substring (stripIndex + 1).Trim ();

                    MeshesToFile (mf, targetFolder, filename);

                }

            } 

            if(GUI.Button (new Rect (10,150,180,30), "Выход")) 
            { 
                window = 5; 
            } 
        } 

        if(window == 5) 
        { 
            GUI.Label(new Rect(50, 10, 180, 30), "Вы уже выходите?");   
            if(GUI.Button (new Rect (10,40,180,30), "Да")) 
            { 
                Application.Quit(); 
            } 
            if(GUI.Button (new Rect (10,80,180,30), "Нет")) 
            { 
                window = 1; 
            } 
        } 
        GUI.EndGroup (); 
    } 
} 

Answer 1

Before using any Unity API, it is very important to check the API namespace. If the namespace is from UnityEditor then it is only meant to work in the Editor only. This is used to make an Editor plugin. You can't use it in a build and it will throw an error when building for any platform.

According the docs, AssetDatabase and EditorUtility class are from the UnityEditor namespace.

You have to re-design your game to work without the GetAssetPath function. You can definitely make a game without that function. I can't tell what you are doing but you should look into the Resources class. This will help you load your GameObjects during run-time.

To solve your current problem,

Replace

using UnityEditor;

with

#if UNITY_EDITOR
using UnityEditor;
#endif

Then replace

objMaterial.textureName = EditorUtility.GetAssetPath(mats[material].mainTexture);

with

        objMaterial.textureName = "";
#if UNITY_EDITOR
        objMaterial.textureName = EditorUtility.GetAssetPath(mats[material].mainTexture);
#endif

You can also put your Menu script in a folder in the Assets/Editor directory but please understand that this does not solve the problem that your code won't work in a build. It will only allow your project to build without those errors in your question. The classes from the UnityEditor namespace are only used for Editor plugin.

Answer 2

This happens because classes that are using UnityEditor need to be put under a folder called Editor: Assets/Editor If you do that, the problem will be gone