c#文件下载

  1 using System;
  2 using System.Collections.Generic;
  3 using System.ComponentModel;
  4 using System.Data;
  5 using System.Drawing;
  6 using System.IO;
  7 using System.Linq;
  8 using System.Net;
  9 using System.Text;
 10 using System.Threading.Tasks;
 11 using System.Windows.Forms;
 12 
 13 namespace WindowsFormsApp1
 14 {
 15     public partial class Form2 : Form
 16     {
 17         public Form2()
 18         {
 19             InitializeComponent();
 20         }
 21         
 22         private void Form1_Load(object sender, EventArgs e)
 23         {
 24         }
 25 
 26         
 27         private void button3_Click(object sender, EventArgs e)
 28         {
 29             string path;
 30             string FileName;
 31             string Url;
 32             string strName;
 33             string finalName;
 34             Url = "https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=72854971,1442321265&fm=23&gp=0.jpg";
 35             //Url = "http://vjs.zencdn.net/v/oceans.mp4";
 36 
 37 
 38             finalName =Url .Substring(Url .LastIndexOf("."));  //后缀名
 39             strName = DateTime.Now.Ticks.ToString();   //前缀名
 40             path = Environment.CurrentDirectory + "\\images\\";
 41 
 42             if(Directory.Exists(path) == false)
 43             {
 44                 DirectoryInfo directoryInfo = new DirectoryInfo(path);
 45                 directoryInfo.Create();
 46             }
 47 
 48             FileName = path + strName + finalName;
 49             
 50             if (SavePhotoFromUrl(FileName, Url))
 51             {
 52                 MessageBox.Show("文件下载成功");
 53             }
 54             else
 55             {
 56                 MessageBox.Show("文件下载失败");
 57 
 58             }
 59         }
 60      
 61 
 62         public static bool SavePhotoFromUrl(string FileName, string Url)
 63         {
 64             bool Value = false;
 65             WebResponse response = null;
 66             Stream stream = null;
 67 
 68             try
 69             {
 70                 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
 71 
 72                 response = request.GetResponse();
 73                 stream = response.GetResponseStream();
 74 
 75                 if (!response.ContentType.ToLower().StartsWith("text/html"))
 76                 {
 77                     Value = SaveBinaryFile(response, FileName);
 78 
 79                 }
 80 
 81             }
 82             catch (Exception err)
 83             {
 84                 string aa = err.ToString();
 85             }
 86             return Value;
 87         }
 88 
 89         private static bool SaveBinaryFile(WebResponse response, string FileName)
 90         {
 91             bool Value = true;
 92             byte[] buffer = new byte[1024];
 93 
 94             try
 95             {
 96                 if (File.Exists(FileName))
 97                     File.Delete(FileName);
 98                 Stream outStream = System.IO.File.Create(FileName);
 99                 Stream inStream = response.GetResponseStream();
100 
101                 int l;
102                 do
103                 {
104                     l = inStream.Read(buffer, 0, buffer.Length);
105                     if (l > 0)
106                         outStream.Write(buffer, 0, l);
107                 }
108                 while (l > 0);
109 
110                 outStream.Close();
111                 inStream.Close();
112             }
113             catch
114             {
115                 Value = false;
116             }
117             return Value;
118         }
119 
120     }
121 }