garden_client/Assets/Script/Editor/EdiotExcelExport.cs

using UnityEngine;

using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Data.OleDb;
using UnityEditor;

[CustomEditor(typeof(ExcelExport))]
public class EdiotExcelExport : Editor
{
    [MenuItem("DashGame/Design Tools/ExportSignConfig")]
    public static void ExportSignConfig()
    {
        string connStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Assets/XlsxSource/signin_config.xls;" + "Extended Properties='Excel 8.0'";

        OleDbConnection connection = new OleDbConnection(connStr);
        connection.Open();

        DataSet dataSet = new DataSet();
        OleDbDataAdapter adapter = new OleDbDataAdapter("select * from [Sheet1$]", connection);

        adapter.Fill(dataSet);

        Debug.Log(dataSet.Tables[0].Columns);
    }
}