/// <summary>
/// 升级缓存
/// </summary>
/// <param name="channels">需要缓存的频道列表</param>
/// <returns></returns>
private async Task AddCacheChannel(params Channel[] channels)
{
var list = channels.Distinct().ToArray();
var localFolder = ApplicationData.Current.LocalFolder;
var file = await localFolder.CreateFileAsync("CacheList.json", CreationCollisionOption.OpenIfExists);
string content = await FileIO.ReadTextAsync(file);
if (string.IsNullOrEmpty(content))
{
content = "[]";
}
var results = JsonConvert.DeserializeObject <List <CacheModel> >(content);
var tasks = new List <Task>();
if (list.Length > 0)
{
foreach (var channel in list)
{
tasks.Add(Task.Run(async() =>
{
var articles = await AppTools.GetSchemaFromUrl(channel.Link, true);
int now = AppTools.DateToTimeStamp(DateTime.Now.ToLocalTime());
if (results.Any(p => p.Channel.Link == channel.Link))
{
var target = results.Where(p => p.Channel.Link == channel.Link).First();
target.Feeds = articles;
target.CacheTime = now;
}
else
{
results.Add(new CacheModel()
{
Channel = channel, Feeds = articles, CacheTime = now
});
}
}));
}
try
{
Task.WaitAll(tasks.ToArray(), new TimeSpan(0, 0, 24));
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
finally
{
content = JsonConvert.SerializeObject(results);
await FileIO.WriteTextAsync(file, content);
}
}
}
/// <summary>
/// 从文件中获取需要通知的源，利用Task的并行，最大限度地获取选取源的更新信息
/// 以获取源的第一篇文章为参照，若该文章已读，说明用户已经打开频道看过了，此时没有通知的必要
/// 若第一篇文章已经出现在已推送列表中，表面该源没有更新文章，同样不推送
/// 若以上条件均不满足，则推送第一篇文章进行简单提醒即可。
/// </summary>
/// <param name="taskInstance"></param>
async void IBackgroundTask.Run(IBackgroundTaskInstance taskInstance)
{
var def = taskInstance.GetDeferral();
var toastList = await GetNeedToastChannels();
var historyList = await GetToastHistory();
var tasks = new List <Task>();
var readList = await GetAlreadyReadFeed();
foreach (var t in toastList)
{
tasks.Add(Task.Run(async() =>
{
try
{
var items = await AppTools.GetSchemaFromUrl(t.Link);
if (items != null && items.Count > 0)
{
string title = t.Name;
string content = string.Empty;
var history = historyList.Where(h => h.ChannelId == t.Id).FirstOrDefault();
var first = items.First();
if (history == null)
{
historyList.Add(new ChannelTarget()
{
ChannelId = t.Id, LastArticleId = first.InternalID
});
if (!readList.Any(p => p == first.InternalID))
{
content = first.Title;
}
}
else
{
if (first.InternalID != history.LastArticleId)
{
if (!readList.Any(p => p == first.InternalID))
{
content = first.Title;
history.LastArticleId = first.InternalID;
}
}
}
if (!string.IsNullOrEmpty(content))
{
SendNotification(title, first);
}
}
}
catch (Exception ex)
{
Debug.WriteLine(ex.InnerException.Message);
}
}));
}
Task.WaitAll(tasks.ToArray(), 24000);
await ReplaceToastHistory(historyList);
def.Complete();
}
