根据地址下载图片

方法一：根据路径下载图片

 1 /// <summary>
 2 /// 图片另存为
 3 /// </summary>
 4 /// <param name="url">路径</param>
 5 public void ImgSave(string url)
 6 {
 7 　　//http://203.156.245.58/sipgl/index.jsp
 8 　　url = "http://203.156.245.58/sipgl/login/img";
 9 　　WebRequest imgRequest = WebRequest.Create(url);
10 
11 　　HttpWebResponse res;
12 　　try
13 　　{
14 　　　　res = (HttpWebResponse)imgRequest.GetResponse();
15 　　}
16 　　　　catch (WebException ex)
17 　　{
18 
19 　　res = (HttpWebResponse)ex.Response;
20 　　}
21 
22 　　if (res.StatusCode.ToString() == "OK")
23 　　{
24 　　　　System.Drawing.Image downImage = System.Drawing.Image.FromStream(imgRequest.GetResponse().GetResponseStream());
25 
26 　　　　string deerory = string.Format(@"D:img{0}", DateTime.Now.ToString("yyyy-MM-dd"));
27 
28 　　　　string fileName = string.Format("{0}.png", DateTime.Now.ToString("HHmmssffff"));
29 
30 
31 　　if (!System.IO.Directory.Exists(deerory))
32 　　{
33 　　　　System.IO.Directory.CreateDirectory(deerory);
34 　　}
35 　　　　downImage.Save(deerory + fileName);
36 　　　　downImage.Dispose();
37 　　}
38 
39 }
40 
41  

方法二：根据路径下载图片 

 1      /// <summary>
 2         /// 下载图片
 3         /// </summary>
 4         /// <param name="picUrl">图片Http地址</param>
 5         /// <param name="savePath">保存路径</param>
 6         /// <param name="timeOut">Request最大请求时间，如果为-1则无限制</param>
 7         /// <returns></returns>
 8         public  bool DownloadPicture(string picUrl, string savePath, int timeOut)
 9         {
10             picUrl = "http://203.156.245.58/sipgl/login/img";
11             savePath = "D:/img/"+DateTime.Now.ToString("HHmmssffff")+".jpg";
12             bool value = false;
13             WebResponse response = null;
14             Stream stream = null;
15             try
16             {
17                 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(picUrl);
18                 if (timeOut != -1) request.Timeout = timeOut;
19                 response = request.GetResponse();
20                 stream = response.GetResponseStream();
21                 if (!response.ContentType.ToLower().StartsWith("text/"))
22                     value = SaveBinaryFile(response, savePath);
23             }
24             finally
25             {
26                 if (stream != null) stream.Close();
27                 if (response != null) response.Close();
28             }
29             return value;
30         }
31         private static bool SaveBinaryFile(WebResponse response, string savePath)
32         {
33             bool value = false;
34             byte[] buffer = new byte[1024];
35             Stream outStream = null;
36             Stream inStream = null;
37             try
38             {
39                 if (File.Exists(savePath)) File.Delete(savePath);
40                 outStream = System.IO.File.Create(savePath);
41                 inStream = response.GetResponseStream();
42                 int l;
43                 do
44                 {
45                     l = inStream.Read(buffer, 0, buffer.Length);
46                     if (l > 0) outStream.Write(buffer, 0, l);
47                 } while (l > 0);
48                 value = true;
49             }
50             finally
51             {
52                 if (outStream != null) outStream.Close();
53                 if (inStream != null) inStream.Close();
54             }
55             return value;
56         }