/// <summary>
/// Takes a new snapshot image.
/// </summary>
/// <param name="token">The token that can be used to cancel the operation.</param>
/// <remarks>Requires Visitor privileges.</remarks>
/// <returns>The current snapshot image.</returns>
public async Task <GetSnapshotResult> GetSnapshotAsync(CancellationToken token)
{
// Input validation.
Contract.Ensures(Contract.Result <GetSnapshotResult>() != null);
const string commandName = "snapPicture2";
GetSnapshotResult result;
// Build the command URL.
string url = this.BuildCommandUrl(commandName);
// Execute the command and download the raw XML result string.
using (HttpClient client = new HttpClient())
{
// NOTE: ConfigureAwait is added to avoid blocking UI threads. See: http://blog.stephencleary.com/2012/07/dont-block-on-async-code.html
HttpResponseMessage response = await client.GetAsync(url, token).ConfigureAwait(false);
string contentType = response.Content.Headers.ContentType.MediaType;
// In case of error the standard XML result structure is returned, and the HTTP status code remains 200 OK.
if (contentType.Equals("text/plain", StringComparison.OrdinalIgnoreCase))
{
string content = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
// Convert the raw XML content string to the expected result type.
TextReader reader = new StringReader(content);
XmlSerializer serializer = new XmlSerializer(typeof(GetSnapshotResult));
result = (GetSnapshotResult)serializer.Deserialize(reader);
}
else
{
// In case of success the body of the HTTP response contains the snapshot image.
byte[] content = await response.Content.ReadAsByteArrayAsync().ConfigureAwait(false);
result = new GetSnapshotResult
{
Result = CommandResult.Success,
MediaType = contentType,
Image = content
};
}
return(result);
}
}
/// <summary>
/// Takes a new snapshot image.
/// </summary>
/// <param name="token">The token that can be used to cancel the operation.</param>
/// <remarks>Requires Visitor privileges.</remarks>
/// <returns>The current snapshot image.</returns>
public async Task<GetSnapshotResult> GetSnapshotAsync( CancellationToken token )
{
// Input validation.
Contract.Ensures( Contract.Result<GetSnapshotResult>() != null );
const string commandName = "snapPicture2";
GetSnapshotResult result;
// Build the command URL.
string url = this.BuildCommandUrl( commandName );
// Execute the command and download the raw XML result string.
using( HttpClient client = new HttpClient() )
{
// NOTE: ConfigureAwait is added to avoid blocking UI threads. See: http://blog.stephencleary.com/2012/07/dont-block-on-async-code.html
HttpResponseMessage response = await client.GetAsync( url, token ).ConfigureAwait( false );
string contentType = response.Content.Headers.ContentType.MediaType;
// In case of error the standard XML result structure is returned, and the HTTP status code remains 200 OK.
if( contentType.Equals( "text/plain", StringComparison.OrdinalIgnoreCase ) )
{
string content = await response.Content.ReadAsStringAsync().ConfigureAwait( false );
// Convert the raw XML content string to the expected result type.
TextReader reader = new StringReader( content );
XmlSerializer serializer = new XmlSerializer( typeof( GetSnapshotResult ) );
result = (GetSnapshotResult) serializer.Deserialize( reader );
}
else
{
// In case of success the body of the HTTP response contains the snapshot image.
byte[] content = await response.Content.ReadAsByteArrayAsync().ConfigureAwait( false );
result = new GetSnapshotResult
{
Result = CommandResult.Success,
MediaType = contentType,
Image = content
};
}
return result;
}
}
