此文记录的是下载网络文件的操作类。
/***网络文件下载器Austin Liu 刘恒辉Project Manager and Software DesignerE-Mail: lzhdim@163.comBlog: http://lzhdim.cnblogs.comDate: 2024-01-15 15:18:00使用方法：DownloadWebFileUtil.DownloadFile("https://lzhdim.cnblogs.com/default.html","d:\default.html"):***/namespace Lzhdim.LPF.Utility
{using System;using System.IO;using System.Net;using System.Text;using System.Net.Security;using System.Security.Cryptography.X509Certificates;/// <summary>/// 下载网页操作类/// </summary>public static class DownloadWebFileUtil{/// <summary>/// 同步下载方法，支持断点续传，计算下载速度，下载进度/// </summary>/// <param name="url">下载链接</param>/// <param name="savePath">文件保存路径，C://xxx.zip</param>/// <param name="progressCallBack">进度回调</param>/// <param name="downloadMsgCallBack">速度回调</param>/// <returns>true:下载成功，false:下载失败</returns>public static bool DownloadFile(string url, string savePath, Action<double> progressCallBack = null, Action<string> downloadMsgCallBack = null){ServicePointManager.DefaultConnectionLimit = 50;string responseContent = "";HttpWebRequest httpWebRequest = null;try{if (string.IsNullOrEmpty(savePath))return false;long rangeBegin = 0;//记录已经下载了多少if (File.Exists(savePath))rangeBegin = new FileInfo(savePath).Length;if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase)){ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);ServicePointManager.Expect100Continue = true;ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;httpWebRequest = WebRequest.Create(url) as HttpWebRequest;}elsehttpWebRequest = (HttpWebRequest)WebRequest.Create(url);//httpWebRequest.Timeout = 300000;//httpWebRequest.ReadWriteTimeout = 60 * 1000;httpWebRequest.Method = "GET";httpWebRequest.KeepAlive = false;httpWebRequest.ServicePoint.Expect100Continue = false;httpWebRequest.Proxy = null;if (rangeBegin > 0)httpWebRequest.AddRange(rangeBegin);using (HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse()){using (Stream responseStream = httpWebResponse.GetResponseStream()){if (responseStream == null)return false;long totalLength = httpWebResponse.ContentLength;if (totalLength == rangeBegin){progressCallBack?.Invoke(100);return true;}if (totalLength == 0 || rangeBegin > totalLength){progressCallBack?.Invoke(0);return false;}long offset = rangeBegin;long oneSecondDonwload = 0;var beginSecond = DateTime.Now.Second;//savePath = Path.Combine(savePath,
httpWebResponse.ResponseUri.LocalPath.Substring(
httpWebResponse.ResponseUri.LocalPath.LastIndexOf('/') + 1)); //自动获取文件名using (Stream stream = new FileStream(savePath, FileMode.Append, FileAccess.Write)){byte[] bArr = new byte[1024 * 8 * 1024];int size = 0;while ((size = responseStream.Read(bArr, 0, (int)bArr.Length)) > 0){try{stream.Write(bArr, 0, size);oneSecondDonwload += size;offset = offset + size;var endSencond = DateTime.Now.Second;if (beginSecond != endSencond){string outSize = GetFileSizeTypeBySize(oneSecondDonwload / (endSencond - beginSecond));downloadMsgCallBack?.Invoke($"{outSize}/S");beginSecond = DateTime.Now.Second;oneSecondDonwload = 0;}progressCallBack?.Invoke(Math.Round((offset / (totalLength * 1.0)) * 100, 2));}catch{return false;}}responseContent = savePath;}}httpWebResponse?.Close();}}catch{responseContent = "";return false;}finally{httpWebRequest?.Abort();}return true;}/// <summary>/// 根据URL获取XML文档文本内容/// </summary>/// <param name="URL">XML文件网址</param>/// <returns>XML文本内容</returns>internal static string GetWebXMLFile(string URL){try{start:HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(URL);req.Method = "GET";req.Timeout = 60000;req.KeepAlive = true;req.AllowAutoRedirect = true;HttpWebResponse rps = (HttpWebResponse)req.GetResponse();if (rps.StatusCode != HttpStatusCode.OK){goto start;}Stream respStream = rps.GetResponseStream();using (StreamReader reader = new StreamReader(respStream, Encoding.GetEncoding("utf-8"))){//ReadToEnd方法不好使，有时候抛异常：无法从传输连接中读取数据: 远程主机强迫关闭了一个现有的连接//string text = reader.ReadToEnd();string text = string.Empty;string line = string.Empty;while ((line = reader.ReadLine()) != null){text += line;}reader.Close();return text;}}catch{return string.Empty;}}#region 私有函数/// <summary>/// 临时返回函数/// </summary>/// <param name="sender"></param>/// <param name="certificate"></param>/// <param name="chain"></param>/// <param name="sslPolicyErrors"></param>/// <returns></returns>private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors){return true;}/// <summary>/// 获取文件大小/// </summary>/// <param name="fileSize">文件大小</param>/// <returns>格式化后的文本</returns>private static string GetFileSizeTypeBySize(long fileSize){if (fileSize < 1024)return $"{fileSize}B";if (fileSize / 1024 < 1024)return $"{fileSize / 1024}KB";if (fileSize / (1024 * 1024) < 1024)return $"{fileSize / (1024 * 1024)}MB";elsereturn $"{fileSize / (1024 * 1024 * 1024)}GB";}#endregion 私有函数}
}
)
