private static Session LoadSession(Windows.Storage.Streams.DataReader dr) {
Session rv = new Session();
rv.SessionId = dr.ReadGuid();
rv.SessionDate = dr.ReadDateTime();
int numberOfReadings = dr.ReadInt32();
rv.Readings = new List<Reading>(numberOfReadings);
for (int x = 0; x < numberOfReadings; x++) {
rv.Readings.Add(Reading.LoadReading(dr));
}
return rv;
}
/// <summary>
/// Writes an array of Session objects to local storage.
/// </summary>
/// <param name="sessions">The Session objects to write. This is an array to force it to be a fixed collection by the time it gets here.</param>
/// <returns>A task that can be awaited until the storage completes.</returns>
public static async Task SerializeLocalSessions(Session[] sessions) {
var fileList = await ApplicationData.Current.LocalFolder.GetFilesAsync();
var scratchFile = await ApplicationData.Current.LocalFolder.CreateFileAsync(localScratchSessionsFileName, CreationCollisionOption.ReplaceExisting);
using (var storageTransaction = await scratchFile.OpenTransactedWriteAsync()) {
using (var dw = new Windows.Storage.Streams.DataWriter(storageTransaction.Stream)) {
dw.WriteInt32(sessions.Length);
for (int x = 0; x < sessions.Length; x++) {
sessions[x].WriteSession(dw);
}
storageTransaction.Stream.Size = await dw.StoreAsync();
await storageTransaction.CommitAsync();
}
}
await scratchFile.RenameAsync(localSessionsFileName, NameCollisionOption.ReplaceExisting);
}