Editor拡張でドラッグ＆ドロップした時のファイルパスを取得する

DragAndDropTest.cs

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

public class DragAndDropTest : EditorWindow
{
  
	// Add menu item to the Window menu
	[MenuItem("Window/DragAndDrop")]
	static void Init () {
		// Get existing open window or if none, make a new one:
		EditorWindow.GetWindow<DragAndDropTest>(false, "DragAndDrop");
	}



	GUIContent btnCntent = new GUIContent();
	private SerializedObject m_Object;
	private SerializedProperty m_FilePath;
	private string[] m_paths = new string[0];

	// Implement your own editor GUI here.
	void OnGUI () {


		#region Horizontal
		GUILayout.BeginHorizontal(GUILayout.Width(this.position.width - 20));

		btnCntent.text = "新しく開き直す";
		btnCntent.tooltip = "このウインドウを開きなおす";


		if (GUILayout.Button(btnCntent, GUI.skin.button, GUILayout.Height(20)))
		{
			this.Close();
			Init();
		}


		GUILayout.EndHorizontal();
		#endregion Horizontal


		var evt = Event.current;

		var dropArea = GUILayoutUtility.GetRect(0.0f, 50.0f, GUILayout.ExpandWidth(true));
		GUI.Box(dropArea, "Drag & Drop");
		switch (evt.type)
		{
			case EventType.DragUpdated:
			case EventType.DragPerform:
				if (!dropArea.Contains(evt.mousePosition)) break;


				//マウスの形状
				DragAndDrop.visualMode = DragAndDropVisualMode.Copy;

				if (evt.type == EventType.DragPerform)
				{
					DragAndDrop.AcceptDrag();

					m_paths = DragAndDrop.paths;

					foreach (string path in DragAndDrop.paths)
					{
						//GetFullPath(path);
					}

					foreach (var draggedObject in DragAndDrop.objectReferences)
					{
						Debug.Log(draggedObject);
					}
					DragAndDrop.activeControlID = 0;
				}
				Event.current.Use();
				break;
		}


		foreach (string path in m_paths)
		{
			EditorGUILayout.TextField("DragAndDrop.path", path);
			EditorGUILayout.TextField("FullPath", GetFullPath(path));
			EditorGUILayout.Space();
		}

	}


	private bool IsMyAssetsPath(string path)
	{
		if (path.IndexOf("Assets/") == 0)
		{
			return true;
		}
		return false;
	}


	private string GetFullPath(string path)
	{
		if (IsMyAssetsPath(path))
		{
			path = path.Substring("Assets/".Length);
			path = Application.dataPath + "/" + path;
		}
		else if (Path.GetFileName(path) == path)
		{
			path = Application.dataPath + "/../" + path;
			path = Path.GetFullPath(path);
		}
		return path;
	}

	
}