/// <summary>
/// Loads user settings from isolated storage.
/// </summary>
/// <remarks>
/// Non-critical exceptions are handled by writing an error message in the output window and
/// returning null.
/// </remarks>
public static async Task <T> LoadAsync <T>(string providerId, string name, Action <T> onLoaded, ConnectedServiceLogger logger) where T : class
{
var fileName = UserSettingsPersistenceHelper.GetStorageFileName(providerId, name);
T result = null;
await UserSettingsPersistenceHelper.ExecuteNoncriticalOperationAsync(
() =>
{
using (var file = UserSettingsPersistenceHelper.GetIsolatedStorageFile())
{
if (file.FileExists(fileName))
{
IsolatedStorageFileStream stream = null;
try
{
stream = file.OpenFile(fileName, FileMode.Open);
var settings = new XmlReaderSettings()
{
XmlResolver = null
};
using (var reader = XmlReader.Create(stream, settings))
{
stream = null;
var dcs = new DataContractSerializer(typeof(T));
result = dcs.ReadObject(reader) as T;
}
}
finally
{
stream?.Dispose();
}
if (onLoaded != null && result != null)
{
onLoaded(result);
}
}
}
},
logger,
"Failed loading the {0} user settings",
fileName);
return(result);
}
/// <summary>
/// Saves user settings to isolated storage. The data is stored with the user's roaming profile.
/// </summary>
/// <remarks>
/// Non-critical exceptions are handled by writing an error message in the output window.
/// </remarks>
public static async Task SaveAsync(object userSettings, string providerId, string name, Action onSaved, ConnectedServiceLogger logger)
{
var fileName = UserSettingsPersistenceHelper.GetStorageFileName(providerId, name);
await UserSettingsPersistenceHelper.ExecuteNoncriticalOperationAsync(
() =>
{
using (var file = UserSettingsPersistenceHelper.GetIsolatedStorageFile())
{
IsolatedStorageFileStream stream = null;
try
{
// note: this overwrites existing settings file if it exists
stream = file.OpenFile(fileName, FileMode.Create);
using (var writer = XmlWriter.Create(stream))
{
stream = null;
var dcs = new DataContractSerializer(userSettings.GetType());
dcs.WriteObject(writer, userSettings);
writer.Flush();
}
}
finally
{
stream?.Dispose();
}
}
onSaved?.Invoke();
},
logger,
"Failed loading the {0} user settings",
fileName);
}