连接丢失时 BinaryReader.Read 不会抛出 IOException

发布于 2024-11-27 22:45:35 字数 1160 浏览 8 评论 0原文

我使用 HttpWebResponse.BeginGetResponse() 方法向我的服务器发出请求。该请求已将AllowReadStreamBuffering 设置为false，以便数据不会被缓冲。在“请求完成”通知中，我执行以下操作（不包含错误处理代码）：

HttpWebResponse response = (HttpWebResponse)myHttpWebRequest.EndGetResponse(result);
BinaryReader streamReader = new BinaryReader(response.GetResponseStream());

try
{
    while ((readSize = streamReader.Read(buffer, 0, buffer.Length)) > 0)
    {
    ...
    }
}
catch (Exception)
{   // NEVER GET HERE!!
...
}

我的问题是，在从流读取数据期间（在 while 循环期间），我无法检测到连接错误。这种行为非常奇怪：它完成读取操作系统在缓存中的所有数据，然后返回“readSize = 0”，就像“流结束”的情况一样。我原以为streamReader.Read()会抛出IOException异常但它没有！我试图在某处找到 stream failed 标志，但似乎没有（Stream/BinaryReader/HttpWebResponse）。请帮忙！

我使用三种场景进行了测试，所有场景都具有相同的行为：

使用手机到 PC 的 USB 连接
- 使用 PC USB 连接将手机连接到互联网
- 在成功调用几次streamReader.Read()后，我禁用了PC网卡
使用 WIFI 连接
- 手机使用 WIFI 连接到互联网
- 成功调用几次streamReader.Read()后，我关闭了WIFI路由器
使用 WIFI 连接
- 手机使用 WIFI 连接到互联网
- 在成功调用几次streamReader.Read()之后，我移除了WAN电缆（因此它无法访问互联网）。

谢谢你！米哈伊

原文

I use HttpWebResponse.BeginGetResponse() method to make a request to my server. The request has AllowReadStreamBuffering set to false so that the data will not be buffered. In the "Request Complete" notification I do the following (no error handling code included):

HttpWebResponse response = (HttpWebResponse)myHttpWebRequest.EndGetResponse(result);
BinaryReader streamReader = new BinaryReader(response.GetResponseStream());

try
{
    while ((readSize = streamReader.Read(buffer, 0, buffer.Length)) > 0)
    {
    ...
    }
}
catch (Exception)
{   // NEVER GET HERE!!
...
}

My problem is that I cannot detect connection errors during reading data from stream (during the while loop). The behavior is very strange: it finishes to read all data that the OS has in the cache and then returns 'readSize = 0' as in the case of "end of stream".
I was expecting streamReader.Read() to throw an IOException exception but it does not!
I tried to find a stream failed flag somewhere but it seems that there is none (Stream/BinaryReader/HttpWebResponse). Please help!

I tested this by using three scenarios and all had the same behavior:

Using the phone-to-PC USB connection
- Phone connected to Internet using the PC USB connection
- After few streamReader.Read() successful calls I disable the PC network card
Using WIFI connection
- Phone connected to Internet using WIFI connection
- After few streamReader.Read() successful calls I power off the WIFI router
Using WIFI connection
- Phone connected to Internet using WIFI connection
- After few streamReader.Read() successful calls I remove WAN cable (so it has no Internet access).

Thank you!
Mihai

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