WebClient does not support concurrent I/O operations 错误的解决办法
贴出一下自己的出错代码:
WebClient client = new WebClient(); // 这句话应该放到for循环里. for (int i = 0; i < mEmotionUrl.Count; i++) { string a = mEmotionUrl[i].Url; client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted); client.OpenReadAsync(new Uri(a, UriKind.RelativeOrAbsolute)); }
最后,google 了半天,并看了许多资料,发现 只要错误信息含有 does not support concurrent I/O operations 信息的,都是由 一个实例同时在多个地方调用产生的,通俗易懂的说,就是并发引起的。下面摘录一句google到得解释:
I don't think you can use a single WebClient instance to execute several
HTTP requests at the same time. Try to create a WebClient instance per request,
that should work just fine.
原来自己的 client 只有一个实例引发多个调用,就报了上述错误
解决办法 :每个使用到 WebClient 的地方,都 new 一个 WebClient 实例,防止出现并发。同时 does not support concurrent I/O operations 错误的方法,一般也是由于 并发引起的,解决方法请参照上一句。