在通用处理程序.ashx中，保存为提示“图像名称”？

Question

当我使用Handler.ashx从文件夹中显示图像，然后尝试通过右键单击它保存图像时，它会一直给我提供“另存为类型”选项的ASP.NET通用处理程序和处理程序名称作为文件名。

Bitmap target = new Bitmap(width, height);
    using (Graphics graphics = Graphics.FromImage(target)) {
        graphics.CompositingQuality = CompositingQuality.HighSpeed;
        graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
        graphics.CompositingMode = CompositingMode.SourceCopy;
        graphics.DrawImage(photo, 0, 0, width, height);
        using (MemoryStream memoryStream = new MemoryStream()) {
            target.Save(memoryStream, ImageFormat.Png);
            OutputCacheResponse(context, File.GetLastWriteTime(photoPath));
            using (FileStream diskCacheStream = new FileStream(cachePath, FileMode.CreateNew))
            {
                memoryStream.WriteTo(diskCacheStream);
            }
            memoryStream.WriteTo(context.Response.OutputStream);
        }
    }

以上是处理器。

ImageTiff.ImageUrl = "Handler.ashx?p=" + Parameter; 

这是代码的实现。

我需要将其保存为图像名称，而不是handler.ashx处理程序。

- Fhd.ashraf

Answer 1

在发送数据之前，您应该设置ContentType和Content-Disposition HTTP头：

context.Response.ContentType = "image/png";
context.Response.Headers["Content-Disposition"] = "attachment; filename=yourfilename.png";

- driis

---

我已经尝试了所有的方法，仍然得到相同的错误！已经浪费了近两个小时！ - Fhd.ashraf

@Fhd，但我在您发布的成本中没有看到这一点。 - Joel Coehoorn

文件名应该放在引号中：filename=\"yourfilename.png\"，否则Firefox可能会出现问题。至于使右键单击=>“另存为”起作用-没有机会这样做。 - Michael Stum

Answer 2

          context.Response.ContentType = "image/pjpeg"; 
          context.Response.AddHeader("Content-Disposition", "attachment; filename=\"" + photoName  + "\"");

          OutputCacheResponse(context, File.GetLastWriteTime(photoPath));

           context.Response.Flush();


           using (FileStream diskCacheStream = new FileStream(cachePath, FileMode.CreateNew))
           {
               memoryStream.WriteTo(diskCacheStream);
           }
            memoryStream.WriteTo(context.Response.OutputStream);

晚上好的睡眠和你们的帮助解决了问题，谢谢大家！

- Fhd.ashraf

Answer 3

当您希望用户保存文件时，需要发送“application/octet-stream”的ContentType。

以下是我们使用的代码（使用vb.net编写，抱歉）（我刚刚验证了，当从ashx请求时，确实会为用户生成正确的文件名）：

    With context
        Try
            ' Remove what other controls may have been put on the page
            .ClearContent()
            ' Clear any headers
            .ClearHeaders()
        Catch theException As System.Web.HttpException
            ' Ignore this exception, which could occur if there were no HTTP headers in the response
        End Try

        .ContentType = "application/octet-stream"
        .AddHeader("Content-Disposition", "attachment; filename=" & sFileNameForUser)

        .TransmitFile(sFileName)

        ' Ensure the file is properly flushed to the user
        .Flush()

        ' Ensure the response is closed
        .Close()

        Try
            .End()
        Catch
        End Try

    End With

C# 翻译：

try
{
        // Remove what other controls may have been put on the page
    context.ClearContent();
        // Clear any headers
    context.ClearHeaders();
}
catch (System.Web.HttpException theException)
{
        // Ignore this exception, which could occur if there were no HTTP headers in the response
}

context.ContentType = "application/octet-stream";
context.AddHeader("Content-Disposition", "attachment; filename=" + sFileNameForUser);

context.TransmitFile(sFileName);

    // Ensure the file is properly flushed to the user
context.Flush();

    // Ensure the response is closed
context.Close();

try
{
    context.End();
}
catch
{
}

- competent_tech