C# 控制台应用程序使用”WebClient“下载文件

遇到个需求，调用第三方Api获取文件并读取文件内容插入到数据库，记录一下：

class Program
    {
        static void Main(string[] args)
        {
            #region  下载文件
            var url = "Api地址";
            var download = new WebClient();
            ServicePointManager.Expect100Continue = true;
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
            ServicePointManager.ServerCertificateValidationCallback = (sender, certificate, chain, errors) => true;
            string saveDirpath = AppSetting.FilePtah;//设置的地址，例：D:\
            string fileName = Guid.NewGuid().ToString();
            string saveFilePath = $"{saveDirpath}\\{fileName}.csv";
            if (!Directory.Exists(saveDirpath))
            {
                Directory.CreateDirectory(saveDirpath);
            }
            download.DownloadFile(url, saveFilePath);
            #endregion

            #region  读取文件并插入数据库
            FileStream fs = new FileStream(saveFilePath, FileMode.Open, FileAccess.Read);
            StreamReader sr = new StreamReader(fs, Encoding.Default);
            DataTable dt = new DataTable();
            //记录每次读取的一行记录
            string strLine = "";
            //记录每行记录中的各字段内容
            string[] aryLine = null;
            string[] tableColumn = null;
            //标示是否是读取的第一行
            bool IsFirst = true;
            //逐行读取CSV中的数据
            while ((strLine = sr.ReadLine()) != null)
            {
                if (IsFirst == true)
                {
                    tableColumn = strLine.Split(',');
                    IsFirst = false;
                }
                else
                {
                    aryLine = strLine.Split(',');
                    SortedList pairs = new SortedList();
                    for (int i = 0; i < tableColumn.Length; i++)
                    {
                        pairs.Add(tableColumn[i], aryLine[i]);
                    }
                    DBHelper.Default.Insert("表名", pairs);//插入数据库操作
                }
            }
            sr.Close();
            fs.Close();
            #endregion

            #region  读取完成，删除文件
            if (File.Exists(saveFilePath))
            {
                File.Delete(saveFilePath);
            }
            #endregion
        }
    }

public int Insert(string TableName, SortedList Insert_ColumnsNameAndValue)
{
        string sql = "INSERT INTO " + TableName;
        sql += "(";
        for (int i = 0; i < Insert_ColumnsNameAndValue.Count; i++)
        {
            sql += i > 0 ? "," : "";
            sql += Insert_ColumnsNameAndValue.GetKey(i);
        }
        sql += ")";
        sql += " values ";
        sql += "(";
        for (int i = 0; i < Insert_ColumnsNameAndValue.Count; i++)
        {
            sql += i > 0 ? "," : "";
            sql += "'" + Insert_ColumnsNameAndValue.GetByIndex(i) + "'";
        }
        sql += ")";
        int count = this.ExecuteNonQuery(sql);
        return count;
}