/// <summary>
/// This is the click handler for the 'Copy Strings' button. Here we will parse the
/// strings contained in the ElementsToWrite text block, write them to a stream using
/// DataWriter, retrieve them using DataReader, and output the results in the
/// ElementsRead text block.
/// </summary>
/// <param name="sender">Contains information about the button that fired the event.</param>
/// <param name="e">Contains state information and event data associated with a routed event.</param>
private async void TransferData(object sender, RoutedEventArgs e)
{
// Initialize the in-memory stream where data will be stored.
using (var stream = new Windows.Storage.Streams.InMemoryRandomAccessStream())
{
// Create the data writer object backed by the in-memory stream.
using (var dataWriter = new Windows.Storage.Streams.DataWriter(stream))
{
dataWriter.UnicodeEncoding = Windows.Storage.Streams.UnicodeEncoding.Utf8;
dataWriter.ByteOrder = Windows.Storage.Streams.ByteOrder.LittleEndian;
// Write each element separately.
foreach (string inputElement in inputElements)
{
uint inputElementSize = dataWriter.MeasureString(inputElement);
dataWriter.WriteUInt32(inputElementSize);
dataWriter.WriteString(inputElement);
}
// Send the contents of the writer to the backing stream.
await dataWriter.StoreAsync();
// For the in-memory stream implementation we are using, the flushAsync call is superfluous,
// but other types of streams may require it.
await dataWriter.FlushAsync();
// In order to prolong the lifetime of the stream, detach it from the DataWriter so that it
// will not be closed when Dispose() is called on dataWriter. Were we to fail to detach the
// stream, the call to dataWriter.Dispose() would close the underlying stream, preventing
// its subsequent use by the DataReader below.
dataWriter.DetachStream();
}
// Create the input stream at position 0 so that the stream can be read from the beginning.
stream.Seek(0);
using (var dataReader = new Windows.Storage.Streams.DataReader(stream))
{
// The encoding and byte order need to match the settings of the writer we previously used.
dataReader.UnicodeEncoding = Windows.Storage.Streams.UnicodeEncoding.Utf8;
dataReader.ByteOrder = Windows.Storage.Streams.ByteOrder.LittleEndian;
// Once we have written the contents successfully we load the stream.
await dataReader.LoadAsync((uint)stream.Size);
var receivedStrings = "";
// Keep reading until we consume the complete stream.
while (dataReader.UnconsumedBufferLength > 0)
{
// Note that the call to readString requires a length of "code units" to read. This
// is the reason each string is preceded by its length when "on the wire".
uint bytesToRead = dataReader.ReadUInt32();
receivedStrings += dataReader.ReadString(bytesToRead) + "\n";
}
// Populate the ElementsRead text block with the items we read from the stream.
ElementsRead.Text = receivedStrings;
}
}
}
/// <summary>
/// This is the click handler for the 'Copy Strings' button. Here we will parse the
/// strings contained in the ElementsToWrite text block, write them to a stream using
/// DataWriter, retrieve them using DataReader, and output the results in the
/// ElementsRead text block.
/// </summary>
/// <param name="sender">Contains information about the button that fired the event.</param>
/// <param name="e">Contains state information and event data associated with a routed event.</param>
private async void TransferData(object sender, RoutedEventArgs e)
{
// Initialize the in-memory stream where data will be stored.
using (var stream = new Windows.Storage.Streams.InMemoryRandomAccessStream())
{
// Create the data writer object backed by the in-memory stream.
using (var dataWriter = new Windows.Storage.Streams.DataWriter(stream))
{
dataWriter.UnicodeEncoding = Windows.Storage.Streams.UnicodeEncoding.Utf8;
dataWriter.ByteOrder = Windows.Storage.Streams.ByteOrder.LittleEndian;
// Write each element separately.
foreach (string inputElement in inputElements)
{
uint inputElementSize = dataWriter.MeasureString(inputElement);
dataWriter.WriteUInt32(inputElementSize);
dataWriter.WriteString(inputElement);
}
// Send the contents of the writer to the backing stream.
await dataWriter.StoreAsync();
// For the in-memory stream implementation we are using, the flushAsync call is superfluous,
// but other types of streams may require it.
await dataWriter.FlushAsync();
// In order to prolong the lifetime of the stream, detach it from the DataWriter so that it
// will not be closed when Dispose() is called on dataWriter. Were we to fail to detach the
// stream, the call to dataWriter.Dispose() would close the underlying stream, preventing
// its subsequent use by the DataReader below.
dataWriter.DetachStream();
}
// Create the input stream at position 0 so that the stream can be read from the beginning.
stream.Seek(0);
using (var dataReader = new Windows.Storage.Streams.DataReader(stream))
{
// The encoding and byte order need to match the settings of the writer we previously used.
dataReader.UnicodeEncoding = Windows.Storage.Streams.UnicodeEncoding.Utf8;
dataReader.ByteOrder = Windows.Storage.Streams.ByteOrder.LittleEndian;
// Once we have written the contents successfully we load the stream.
await dataReader.LoadAsync((uint)stream.Size);
var receivedStrings = "";
// Keep reading until we consume the complete stream.
while (dataReader.UnconsumedBufferLength > 0)
{
// Note that the call to readString requires a length of "code units" to read. This
// is the reason each string is preceded by its length when "on the wire".
uint bytesToRead = dataReader.ReadUInt32();
receivedStrings += dataReader.ReadString(bytesToRead) + "\n";
}
// Populate the ElementsRead text block with the items we read from the stream.
ElementsRead.Text = receivedStrings;
}
}
}
/// <summary>
/// 動作ログを出力する.
/// </summary>
/// <param name="taskInstance"></param>
/// <returns></returns>
async Task WriteLogAsync(IBackgroundTaskInstance taskInstance, SetLockscreenResult result)
{
var log = String.Format("{0}: {1} / {2}, {3}{4}",
DateTimeOffset.Now,
taskInstance.Task.Name,
taskInstance.Task.TaskId,
result,
Environment.NewLine);
System.Diagnostics.Debug.WriteLine(log);
var logfile = await Windows.Storage.ApplicationData.Current.LocalFolder.CreateFileAsync("bgtask.log", Windows.Storage.CreationCollisionOption.OpenIfExists);
if (logfile != null)
{
System.Diagnostics.Debug.WriteLine(logfile.Path);
using (var strm = await logfile.OpenAsync(Windows.Storage.FileAccessMode.ReadWrite))
{
strm.Seek(strm.Size);
using (var dw = new Windows.Storage.Streams.DataWriter(strm))
{
dw.UnicodeEncoding = Windows.Storage.Streams.UnicodeEncoding.Utf16LE;
dw.WriteString(log);
await dw.StoreAsync();
await dw.FlushAsync();
}
}
}
}
