Question

忙着写一些遗留代码写入csv / xls：

// Set up response
string filename = "ErrorControlExport";
string attachment = "attachment; filename=" + filename + "_" + DateTime.UtcNow.ToFileTime() + "." + extension;
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.ClearHeaders();
HttpContext.Current.Response.ClearContent();
HttpContext.Current.Response.AddHeader("content-disposition", attachment);
HttpContext.Current.Response.ContentType = contentType;
HttpContext.Current.Response.AddHeader("Pragma", "public");
// Clear any settings (such as GZip)
HttpContext.Current.Response.Filter = null;//exception occurs here

// Add BOM to force recognition of UTF-8
byte[] bom = new byte[] { 0xef, 0xbb, 0xbf };
HttpContext.Current.Response.BinaryWrite(bom);

但是当代码到达时：

// Clear any settings (such as GZip)
HttpContext.Current.Response.Filter = null;//exception occurs here

它会抛出HttpException

响应过滤器无效。

所以我的问题是：

1）如何将过滤器设置为空过滤器或默认过滤器？

2）是否有必要？

提前感谢您的帮助

Answer 1

检查此post。即使它谈论ASp.Net 3.5，我尝试了它，它的工作原理。我刚刚阅读过滤器var filter = Response.Filter，然后为其分配了空Response.Filter = null

Answer 2

除了@ Nileshs＆＃39;评论/答案（我使用此方法时为+1）

另一种选择是创建一个空过滤器：

/// <summary>
/// Creates and empty filter for HttpResponse.Filter (i.e no proessing is done on the text before writting to the stream)
/// </summary>
class EmptyFilter : MemoryStream
{
    private string source = string.Empty;
    private readonly Stream filter;


    public EmptyFilter(HttpResponse httpResponseBase)
    {
        this.filter = httpResponseBase.Filter;
    }


    public override void Write(byte[] buffer, int offset, int count)
    {
        this.source = Encoding.UTF8.GetString(buffer);

        this.filter.Write(Encoding.UTF8.GetBytes(this.source), offset, Encoding.UTF8.GetByteCount(this.source));
    }
}

而不是简单地设置为：

HttpContext.Current.Response.Filter = new EmptyFilter(HttpContext.Current.Response);

Answer 3

尝试清理您的解决方案并删除旧的DLL（可能是从项目重命名中遗留下来的）。那为我排序了。

HttpContext.Current.Response.Filter：响应过滤器无效

3 个答案: