/// <summary>
/// Opens a readable stream to the specified resource
/// </summary>
public static Task <ArcGISWebClient.OpenReadCompletedEventArgs> OpenReadTaskAsync(
this ArcGISWebClient client, Uri uri, IDictionary <string, string> parameters = null,
ArcGISWebClient.HttpMethods httpMethod = ArcGISWebClient.HttpMethods.Auto, object userState = null)
{
TaskCompletionSource <ArcGISWebClient.OpenReadCompletedEventArgs> tcs =
new TaskCompletionSource <ArcGISWebClient.OpenReadCompletedEventArgs>();
EventHandler <ArcGISWebClient.OpenReadCompletedEventArgs> openReadHandler = null;
openReadHandler = (o, e) =>
{
client.OpenReadCompleted -= openReadHandler;
if (e != null)
{
tcs.TrySetResult(e);
}
else
{
tcs.TrySetException(new Exception(Strings.ExceptionNoResult));
}
};
client.OpenReadCompleted += openReadHandler;
client.OpenReadAsync(uri, parameters, httpMethod, userState);
return(tcs.Task);
}
/// <summary>
/// Issues a GET request to the specified URI and returns the result
/// </summary>
public static Task <ArcGISWebClient.DownloadStringCompletedEventArgs> DownloadStringTaskAsync(
this ArcGISWebClient client, Uri uri, IDictionary <string, string> parameters,
ArcGISWebClient.HttpMethods httpMethod, object userState = null)
{
TaskCompletionSource <ArcGISWebClient.DownloadStringCompletedEventArgs> tcs =
new TaskCompletionSource <ArcGISWebClient.DownloadStringCompletedEventArgs>();
EventHandler <ApplicationUnhandledExceptionEventArgs> unhandledExceptionHandler = null;
EventHandler <ArcGISWebClient.DownloadStringCompletedEventArgs> downloadHandler = null;
// Handle application unhandled exception due to issue with API where uncatchable deserialization
// exception is sometimes thrown for requests that return an error
unhandledExceptionHandler = (o, e) =>
{
DownloadStringTaskInProgress = false;
Application.Current.UnhandledException -= unhandledExceptionHandler;
client.DownloadStringCompleted -= downloadHandler;
e.Handled = true;
tcs.TrySetException(new Exception(Strings.ExceptionNoResult));
};
downloadHandler = (o, e) =>
{
DownloadStringTaskInProgress = false;
if (Application.Current != null)
{
Application.Current.UnhandledException -= unhandledExceptionHandler;
}
client.DownloadStringCompleted -= downloadHandler;
if (e != null)
{
tcs.TrySetResult(e);
}
else
{
tcs.TrySetException(new Exception(Strings.ExceptionNoResult));
}
};
client.DownloadStringCompleted += downloadHandler;
if (Application.Current != null)
{
Application.Current.UnhandledException += unhandledExceptionHandler;
}
DownloadStringTaskInProgress = true;
client.DownloadStringAsync(uri, parameters, httpMethod, userState);
return(tcs.Task);
}
