本文介绍了FTP 处理程序页面,从 aspx 调用字符串帮助初始化处理程序页面的方法的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

嘿伙计们,我试图清理我的上一篇文章,所以就这样吧.

Hey guys, tryed to clean up my last post so here it goes.

我的 asp.net 项目中有一个处理程序页面正在尝试"处理 ftp 下载请求.

I have a handler page in my asp.net project that is "trying" to handle a ftp download request.

GetImage.ashx.cs

GetImage.ashx.cs

public class GetImage : IHttpHandler
{

    public void ProcessRequest(HttpContext context)
    {
        {

            // method for calling PhotoPath from Database.aspx.cs
            FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create(new Uri());
            // (new Uri) I would like to just store "photopath" in here as it has the ftp plus the filename in it
            request.Method = WebRequestMethods.Ftp.DownloadFile;

            request.Credentials = new NetworkCredential("username", "password");

            try
            {
                FtpWebResponse response = (FtpWebResponse)request.GetResponse();

                Stream stream = response.GetResponseStream();
                byte[] bytes = new byte[2048];

                int i = 0;
                MemoryStream mStream = new MemoryStream();

                do
                {

                    i = stream.Read(bytes, 0, bytes.Length);

                    mStream.Write(bytes, 0, i);
                } while (i != 0);

                context.Response.ClearHeaders();
                context.Response.ClearContent();
                context.Response.ContentType = "image/jpeg";
// Response.Headers.Add("Content-Type", "image/jpeg"); this is from the database.aspx page not sure if its correct
                    context.Response.BinaryWrite(mStream.GetBuffer());
                }
                catch (WebException wex)
                {

            }
            catch (Exception ex)
            {
                throw new Exception("An error occurred: " + ex);

            }

        }
    }

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

}

在包含我的 gridview 的页面上,我有一种方法可以从我的一个单元格中提取数据,该单元格包含我试图在我的图像控件中显示的图像的 ftp 路径和文件名:

On my page that holds my gridview I have a method to extract data from one of my cells, this cell contains the ftp path and filename of the image im trying to show in my image control:

数据库.aspx.cs

Database.aspx.cs

protected void Page_Load(object sender, EventArgs e){

        Response.Headers.Add("Content-Type", "image/jpeg");

    }

    protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
    {
        string PhotoPath = "";
        // Get the currently selected row. Because the SelectedIndexChanging event
        // occurs before the select operation in the GridView control, the
        // SelectedRow property cannot be used. Instead, use the Rows collection
        // and the NewSelectedIndex property of the e argument passed to this
        // event handler.
        GridViewRow row = GridView1.Rows[GridView1.SelectedIndex];

        PhotoPath = row.Cells[5].Text;
        // how do I send photopath to my handler page?
        //TextBox1.Text = PhotoPath;
    }
}

}

在我的处理程序页面中,我想调用字符串PhotoPath"并将其放置在我的处理程序页面中的 ftwwebrequest 中:

In my handler page I want to call the string "PhotoPath" and place it in my ftwwebrequest in my handler page:

FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create(new Uri(PhotoPath));

我已经将我的图像控件 ImageUrl 设置为 ~/GetImage.ashx 并且需要一些代码帮助以从我的数据库页面调用处理程序?

Ive set my image control ImageUrl to ~/GetImage.ashx and will need some help with code to call the handler from my database page?

有人可以帮忙吗,因为我已经坚持了很长时间了?

Can any one help because ive been stuck on this for ages?

推荐答案

  • 您需要使用查询字符串将 PhotoPath 传递给 ASHX 处理程序.然后您应该从查询字符串中读取参数并将其传递给 WebRequest.Create
  • 你不应该吞下异常
  • 您不需要清除响应
  • 您应该将 FtpWebResponse 直接复制到 HttpResponse;你不需要中间的 MemoryStream
  • ContentType 属性告诉浏览器您发送的文件类型.请参阅http://en.wikipedia.org/wiki/MIME_type
    • You need to pass PhotoPath to the ASHX handler using the querystring. You should then read the parameter from the querystring and pass it to WebRequest.Create
    • You should not swallow exceptions
    • You don't need to clear the response
    • You should copy the FtpWebResponse directly to the HttpResponse; you don't need an intermediate MemoryStream
    • The ContentType property tells the browser what kind of file you're sending. See http://en.wikipedia.org/wiki/MIME_type
    • 这篇关于FTP 处理程序页面,从 aspx 调用字符串帮助初始化处理程序页面的方法的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

09-05 21:34
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