Asp.net上传文件后台通过二进制流发送到其他Url保存

网址：https://www.cnblogs.com/tongyi/p/4274354.html

实际情况一般有单独的站点存放静态文件，比如图片、office文档等。A站点的操作需要上传文件到B站点，

下面介绍一种方法通过System.Net.WebClient类的UploadData方法 。

uploadFile.aspx html：

<form id="form1" runat="server">
    <div>
        <asp:FileUpload runat="server" ID="fileUp" AllowMultiple="true" /> 
        <asp:Button runat="server" ID="btnLoad" Text="Upload" OnClick="btnLoad_Click" />
    </div>
    </form>

uploadFile.cs 后台代码

 protected void btnLoad_Click(object sender, EventArgs e)
        {
            if (fileUp.HasFile)
            {
                var list = fileUp.PostedFiles;
                foreach (var item in list)
                {
                    string fileDoc = System.IO.Path.GetExtension(item.FileName).ToLower(); //后缀名
                    int fileLength = (int)item.InputStream.Length;//InputStream.Length;

                    byte[] byteFile = new byte[fileLength];
                    item.InputStream.Read(byteFile, 0, fileLength);
                    item.InputStream.Seek(0, System.IO.SeekOrigin.Begin); //读取流之后设置设置当前流的位置，因为md5加密也需要用到该流

                    string md5Value =  Com.MD5.MyMD5.getMd5Hash(item.InputStream); //得到上传文件流的MD5string url = string.Format("http://localhost:4884/SaveFile.ashx?name=" + md5Value + "&ext=" + fileDoc);  //保存流的处理文件路径

                    System.Net.WebClient wc = new System.Net.WebClient();
                    byte[] bts = wc.UploadData(url, "POST", byteFile);
                    wc.Dispose();
                    string filePath = System.Text.Encoding.UTF8.GetString(bts); //获取SaveFile.ashx返回
                }
            }
        }

方法请看：我的C# MD5摘要算法、哈希算法

SaveFile.ashx 处理程序

/// <summary>
/// SaveFile 的摘要说明
/// </summary>
public class SaveFile : IHttpHandler
{

public void ProcessRequest(HttpContext context)
{
lock (context.Request.InputStream)
{
HttpRequest Request = context.Request;
string path = ""; string filenName = "";
string re = "";
if (Request.HttpMethod.ToLower() == "post")
{
try
{
using (Request.InputStream)
{
string name = Request["name"];
string s = Request["ext"];
byte[] bytes = new byte[Request.InputStream.Length];
Request.InputStream.Read(bytes, 0, bytes.Length);
Request.InputStream.Seek(0, SeekOrigin.Begin);//设置当前流的位置
//Request.InputStream.Position = 0;
Request.InputStream.Flush();
Request.InputStream.Close();
Request.InputStream.Dispose();
Random rnd = new Random();
int n = rnd.Next(1000, 9999);
//filenName = "/file/" + n.ToString() + "-" + DateTime.Now.ToString("yyyyMMddHHmmssss") + s;
filenName = "/file/"+name + s;
path = context.Server.MapPath(filenName);

FileStream fs = new FileStream(path, FileMode.Create);
BinaryWriter bw = new BinaryWriter(fs);
bw.Write(bytes);
bw.Close();
fs.Close();
re = filenName;

//System.Threading.Thread.Sleep(500);
}
}
catch (Exception ex)
{

}
}

context.Response.ContentType = "text/plain";
context.Response.Write(re);
context.Response.End();
}
}

public bool IsReusable
{
get
{
return false;
}
}
}

HttpFileCollection：

void save(HttpRequest Request)
{
var file = Request.Files[0];
var filenName = "/file/" + file.FileName;
var path = HttpContext.Current.Server.MapPath(filenName);
file.SaveAs(path);
}