iOS development, the child thread is not able to update the UI

Today, a strange problem is found, when using Nsnotification, TableView in the callback function Reloaddata, and can not update the UI, but also will not be updated later. Later, we found out that the callback function was called after postnotification, which is equivalent to opening a child thread, and the UI cannot be updated in the child thread. So to update the UI in the notification callback, you must use the

Dispatch_async (Dispath_get_main_queue (), ^{

[TableView Reloaddata];

}];

iOS development, the child thread is not able to update the UI