c#.net内部异常捕获问题

public static void Download()
{
int count = 0;
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://img.bimg.126.net/photo/c7bckFJxdJxSwQLIy76HTQ==/1755840904721658663.jpg");
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
byte[] buffer = new byte[64];
string temppath = "g:\\1755840904721658663.jpg";

using (System.IO.Stream downloadStream = response.GetResponseStream())
{
using (FileStream saveFileStream = new FileStream(temppath, FileMode.Create, FileAccess.Write, FileShare.None))
{
int readSize = 0;
while (true)
{
readSize = downloadStream.Read(buffer, 0, buffer.Length);
if (readSize <= 0) break;
saveFileStream.Write(buffer, 0, readSize);
}
Console.WriteLine("弹出");
}
}
}
}
catch (System.Net.Sockets.SocketException ex)
{
Console.WriteLine("网络中断");
}
catch (Exception ex)
{
//throw ex;
Console.WriteLine("异常类型：{0}", ex.GetType());
Console.WriteLine("异常信息：{0}", ex.Message);
Console.WriteLine("异常来源：{0}", ex.Source);
Console.WriteLine("异常堆栈：{0}", ex.StackTrace);
Console.WriteLine("内部异常：{0}", ex.InnerException);
}
}

异常类型：System.IO.IOException
异常信息：无法从传输连接中读取数据: 远程主机强迫关闭了一个现有的连接。。
内部异常：System.Net.Sockets.SocketException (0x80004005): 远程主机强迫关闭了一
个现有的连接。
在 System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size,
SocketFlags socketFlags)
在 System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 s
ize)

IOException.InnerException是因为在读取Stream过程中，网络中断导致。

所以代码中应该加上一个Catch IOException的处理。

...
catch(IOException ex)
{
if(IOException.InnerException is System.Net.Sockets.SocketException)
Console.WriteLine("网络中断");
else
Console.WriteLine(ex.Message);
}
...