public Task createTask(string url, string dir, string fileName)
{
DownloadTask task = new DownloadTask(url, dir, fileName);
task.setStatus(TaskStatus.Waiting);
task.onTaskStatusChanged += this.OnTaskStatusChanged;
task.id = currId+"";
currId++;
lock(lockObj){
waittingTasks.Add(task);
allTasks.Add(task);
}
return task;
}