Level editor – saving/loading levels to file

Now that we have the groundwork all placed and ready, let's get to the real meat of the level editor: saving and loading! Perform the following steps:

1. Open our LevelEditor class in MonoDevelop. The first step will be to include some additional functionality at the beginning of our file:

   //You must include these namespaces
   //to use BinaryFormatter
   using System;
   using System.Runtime.Serialization.Formatters.Binary;
   using System.IO;

2. The first thing we'll want to add is a variable, as follows:

   string levelName = "Level1";

3. Now, we'll need to add the following code to the OnGUI function:

   GUILayout.BeginArea(new Rect(10, 20, 100, 100));
   levelName = GUILayout.TextField(levelName);
   if (GUILayout.Button ("Save"))
   {
     SaveLevel();
   }
   if (GUILayout.Button ("Load"))
   {
     //If we have a file with the name typed in, load it!
     if(File.Exists(Application.persistentDataPath + "/" + levelName + ".lvl"))
     {
       LoadLevelFile(levelName);
       PlayerStart.spawned = false...