{
    class FilePathHelper
    {
        /// <summary>
        /// 選擇儲存檔案的名稱以及路徑  取消返回 空"";
        /// </summary>
        /// <param name="fileName"></param>
        /// <param name="filter"></param>
        /// <param name="title"></param>
        /// <returns></returns>
 

        public static string SaveFilePathName(string fileName=null, string filter=null, string title=null)
        {
            string path = "";
            System.Windows.Forms.SaveFileDialog fbd = new System.Windows.Forms.SaveFileDialog();
            if (!string.IsNullOrEmpty(fileName))
            {
                fbd.FileName 
 
= fileName;
            }
            if (!string.IsNullOrEmpty(filter))
            {
                fbd.Filter = filter;// "Excel|*.xls;*.xlsx;";
            }
            if (!string.IsNullOrEmpty(title))
            {
                fbd.Title = title;// "儲存為";
            }
            if (fbd.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                path 
 
= fbd.FileName;
            }
            return path;
        }
        /// <summary>
        /// 選擇一個檔案
        /// </summary>
        /// <param name="filter">如果需要篩選txt檔案（"Files (*.txt)|*.txt"）</param>
        /// <returns></returns>
        private static string SelectFile(string filter=null)
        {
            string path = string.Empty;
            var openFileDialog = new Microsoft.Win32.OpenFileDialog()
            {
                Filter = "Files (*.*)|*.*"//如果需要篩選txt檔案（"Files (*.txt)|*.txt"）
            };
            if (filter!=null)
            {
                openFileDialog.Filter = filter;
            }
            var result = openFileDialog.ShowDialog();
            if (result == true)
            {
                path = openFileDialog.FileName;
            }
            return path;
        }
        
        /// <summary>
        /// 選擇一個路徑
        /// </summary>
        /// <returns></returns>
        public static string SelectPath()
        {
            string path = string.Empty;
            System.Windows.Forms.FolderBrowserDialog fbd = new System.Windows.Forms.FolderBrowserDialog();
            if (fbd.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                path = fbd.SelectedPath;
            }
            return path;
        }
    }
}

轉載：https://blog.csdn.net/a376143220/article/details/79276562