C#未将对象引用设置到对象的实例

namespace ConnectionAccess

{

    public partial class Frm_Main : Form

    {

        private void Frm_Main_Load()

        {

            string ConStr = string.Format(

                @"Provider=Microsoft.ACE.OleDB.12.0;Data Source='D:\1.accdb'",

                Application.StartupPath);

            OleDbConnection oleCon = new OleDbConnection(ConStr);

            oleCon.Open();

            OleDbDataAdapter oleDap = new OleDbDataAdapter("select * from 物品列表",oleCon);

            DataSet ds = new DataSet();

            oleDap.Fill(ds,"T1");

            if (ds.Tables!= null)

            {                

                dataGridView1.DataSource = ds;

                dataGridView1.DataMember = "T1";                

            }



oleCon.Close();

            oleCon.Dispose();

        }

        public Frm_Main()

        {

            Frm_Main_Load();

            InitializeComponent();

        }

    }

}

程序执行到这一句  dataGridView1.DataSource = ds;
一直提示我ds没有引用到实例  请问以上的代码哪里有错误啊?应该如何改正?
------解决方案--------------------
哦错了, 你把
Frm_Main_Load();
            InitializeComponent();

这两行换下顺序. DataGridView在initialize方法里才New出来