WebClient.DownloadStringAsync Method (Uri, Object)
Downloads the resource at the specified Uri as a string.
Assembly: System.Net (in System.Net.dll)
The address parameter is null.
There is not enough memory to continue the execution of the program.
The execution stack overflowed because it contains too many nested method calls.
A call was made to the Thread.Abort method to destroy a thread.
This method retrieves the specified resource using the GET method. The resource is downloaded asynchronously. When the download is completed, the DownloadStringCompleted event is raised. The downloaded string is available in the Result property of the DownloadStringCompletedEventArgs. You cannot call the DownloadStringAsync method again on the same WebClient object, until the first string download operation is completed. Doing this causes an exception.
You can use the CancelAsync method to cancel asynchronous operations that have not completed.
If the BaseAddress property is not an empty string and the address does not contain an absolute URI, the address must be a relative URI that is combined with BaseAddress to form the absolute URI of the requested data.