利用WebService发布图片文件

服务器端：

1.新建一个Asp.net空网站RGImageServer。

2.新建一个WebService项目ImageService，项目新增文件ImageService.asmx，添加方法GetTile()。

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.Web.Services;
 using System.IO;
 using System.Configuration;

 namespace RGImageServer
 {
     /// <summary>
     /// ImageServices 的摘要说明
     /// </summary>
     [WebService(Namespace = "http://tempuri.org/")]
     [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
     [System.ComponentModel.ToolboxItem(false)]
     // 若要允许使用 ASP.NET AJAX 从脚本中调用此 Web 服务，请取消对下行的注释。
     // [System.Web.Script.Services.ScriptService]
     public class ImageServices : System.Web.Services.WebService
     {

         [WebMethod]
         public string HelloWorld()
         {
             return "Hello World";
         }
         private byte[] Stream2Bytes(Stream theStream)
         {
             int num;
             MemoryStream stream = new MemoryStream();
             while ((num = theStream.ReadByte()) != -1)
             {
                 stream.WriteByte((byte)num);
             }
             theStream.Close();
             return stream.ToArray();
         }
         [WebMethod]
         public void GetTile(string imageName)
         {
             string filename = ConfigurationManager.AppSettings["ImagePath"] + @"\" + imageName;
             HttpContext context = this.Context;
             if (File.Exists(filename))
             {
                 try
                 {
                     FileStream theStream = File.OpenRead(filename);
                     context.Response.ContentType = "image/png";
                     byte[] buffer = Stream2Bytes(theStream);
                     context.Response.OutputStream.Write(buffer, 0, buffer.Length);
                 }
                 catch (Exception)
                 {
                     context.Response.StatusCode = 500;
                 }
             }
         }
     }
 }

3.配置WebConfig文件，发布服务。

 <?xml version="1.0" encoding="utf-8"?>

 <!--
   有关如何配置 ASP.NET 应用程序的详细消息，请访问
   http://go.microsoft.com/fwlink/?LinkId=169433
   -->

 <configuration>
   <system.web>
     <compilation debug="true" targetFramework="4.0" />
     <webServices>
       <protocols>
         <add name="HttpGet" />
         <add name="HttpPost" />
         <add name="HttpSoap" />
       </protocols>
     </webServices>
   </system.web>
   <appSettings>
     <add key="ImagePath" value="E:\"/>
   </appSettings>
 </configuration>

客户端：

1.调用下载图片代码如下：

 public partial class Form1 : Form
     {
         public Form1()
         {
             InitializeComponent();
         }
         Stream ContentStream;
         HttpWebResponse response = null;
         string ContentType;
         string ContentEncoding;
         int ContentLength = ;
         int BytesProcessed;
         private void button1_Click(object sender, EventArgs e)
         {
             ImageServices server = new ImageServices();
             string Url = "http://localhost:6235/ImageServices.asmx/GetTile?imageName=aa.png";
             string SavedFilePath = "D:\\bb.png";
             // Download to file
             string targetDirectory = Path.GetDirectoryName(SavedFilePath);
             if (targetDirectory.Length > )
                 Directory.CreateDirectory(targetDirectory);
             ContentStream = new FileStream(SavedFilePath, FileMode.Create);
             HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
             request.ContentType = "text/xml";
             using (response = request.GetResponse() as HttpWebResponse)
             {
                 // only if server responds 200 OK
                 if (response.StatusCode == HttpStatusCode.OK)
                 {
                     ContentType = response.ContentType;
                     ContentEncoding = response.ContentEncoding;

                     // Find the data size from the headers.
                     string strContentLength = response.Headers["Content-Length"];
                     if (strContentLength != null)
                     {
                         ContentLength = int.Parse(strContentLength);
                     }
                     //缓存字节数组，大小1500byte
                     byte[] readBuffer = new byte[];
                     using (Stream responseStream = response.GetResponseStream())
                     {
                         while (true)
                         {
                             //  Pass do.readBuffer to BeginRead.
                             int bytesRead = responseStream.Read(readBuffer, , readBuffer.Length);
                             if (bytesRead <= )
                                 break;
                             ContentStream.Write(readBuffer, , bytesRead);
                             BytesProcessed += bytesRead;
                         }
                     }
                     ContentStream.Close();
                     ContentStream.Dispose();
                     ContentStream = null;
                 }
             }

         }
     }

以下是一个一般处理程序ImageHandler用于图片发布，添加ImageHandler.ashx：

 using System;
 using System.Web;
 using System.Configuration;
 using System.IO;

 namespace RGImageServer
 {
     /// <summary>
     /// ImageHandler 的摘要说明
     /// </summary>
     public class ImageHandler : IHttpHandler
     {

         public void ProcessRequest(HttpContext context)
         {
             //context.Response.ContentType = "text/plain";
             //context.Response.Write("Hello World");

             string imageName = "aa.png";
             string filename = ConfigurationManager.AppSettings["ImagePath"] + @"\" + imageName;
             if (File.Exists(filename))
             {
                 try
                 {
                     FileStream theStream = File.OpenRead(filename);
                     context.Response.ContentType = "image/png";
                     byte[] buffer = StreamToBytes(theStream);
                     context.Response.OutputStream.Write(buffer, , buffer.Length);
                 }
                 catch (Exception)
                 {

                 }
             }
         }
         private byte[] StreamToBytes(Stream theStream)
         {
             int num;
             MemoryStream stream = new MemoryStream();
             while ((num = theStream.ReadByte()) != -)
             {
                 stream.WriteByte((byte)num);
             }
             theStream.Close();
             return stream.ToArray();
         }
         public bool IsReusable
         {
             get
             {
                 return false;
             }
         }
     }
 }

ImageHandler

通过浏览器可以直接访问：http://localhost:6235/ImageHandler.ashx