winform 下载网络资源

调用

//网络地址 文件的名字 存放本地路径 DownLoadFile.HttpDownload(@"http://39.127.0.1:8092/" + readerppp.GetString(2), "./img/" + readerppp.GetString(2));

工具

using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Net; using System.Text; using System.Windows.Forms; namespace TextWinform1 { class DownLoadFile { /// <summary> /// 专门的下载文件类 /// </summary> /// <summary> /// http下载文件 /// </summary> /// <param name="url"></param> /// <param name="path"></param> /// </summary> /// <param name="url">下载文件地址</param> /// <param name="path">文件存放地址，包含文件名</param> /// <param name="progressBar1"></param> /// <param name="label_Info">提示信息 ，时时提示下载多少K的 </param> /// <returns></returns> public static bool HttpDownload(string url, string path) { string tempPath = System.IO.Path.GetDirectoryName(path); if (!System.IO.Directory.Exists(tempPath)) System.IO.Directory.CreateDirectory(tempPath); string tempFile = tempPath + "/" + System.IO.Path.GetFileName(path); try { FileStream fs = new FileStream(tempFile, FileMode.Append, FileAccess.Write, FileShare.ReadWrite); // 设置参数 HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest; //发送请求并获取相应回应数据 HttpWebResponse response = request.GetResponse() as HttpWebResponse; //直到request.GetResponse()程序才开始向目标网页发送Post请求 Stream responseStream = response.GetResponseStream(); //创建本地文件写入流 //Stream stream = new FileStream(tempFile, FileMode.Create); byte[] bArr = new byte[1024]; int size = responseStream.Read(bArr, 0, (int)bArr.Length); if (response.ContentLength != 0) { if (request.ContentLength > int.MaxValue) { MessageBox.Show("要下载的文件太大，超出范围！"); return false; } } while (size > 0) { //stream.Write(bArr, 0, size); fs.Write(bArr, 0, size); size = responseStream.Read(bArr, 0, (int)bArr.Length); /*progressBar1.Invoke(new Action(() => { progressBar1.Value += size; }));*/ } fs.Close(); responseStream.Close(); //if (System.IO.File.Exists(path)) //{ // System.IO.File.Delete(path); //存在则删除 //} //System.IO.File.Move(tempFile, path); //if (System.IO.File.Exists(tempFile)) //{ // System.IO.File.Delete(tempFile); //存在则删除 //} return true; } catch (Exception ex) { return false; } } delegate void SetTextCallBack(string text, Label txt_a); private static void SetText(string text, Label txt_a) { if (txt_a.InvokeRequired) { SetTextCallBack stcb = new SetTextCallBack(SetText); txt_a.Invoke(stcb, new object[] { text, txt_a }); } else { txt_a.Text = text; } } public static string SendGetRequest(string url) { try { HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); request.Method = "get"; //if (CookiesContainer == null) //{ // CookiesContainer = new CookieContainer(); //} //request.CookieContainer = CookiesContainer; //启用cookie HttpWebResponse response = (HttpWebResponse)request.GetResponse(); Stream response_stream = response.GetResponseStream(); int count = (int)response.ContentLength; int offset = 0; byte[] buf = new byte[count]; while (count > 0) //读取返回数据 { int n = response_stream.Read(buf, offset, count); if (n == 0) break; count -= n; offset += n; } return Encoding.UTF8.GetString(buf); } catch { return null; } } } }