C# openFileDialog的使用方法

    /// <summary>        /// 打开文件        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private void button3_Click(object sender, EventArgs e)        {            FileDialog oneFileDialog1 = new OpenFileDialog();            //openFileDialog1.InitialDirectory = "C:\\";//这一段代码能够执行。            openFileDialog1.Filter = "Excel文件（*.xls）|*.xls";            openFileDialog1.FilterIndex = 0;            //openFileDialog1.RestoreDirectory = true;            //openFileDialog1.ShowHelp = true;            //openFileDialog1.Title = "打开文件";            openFileDialog1.ShowDialog();        }