ios - 调度不能正常工作

Question

我尝试在后台获取一些数据并在搜索栏中输入时刷新表格 View ，这是我当前的代码:

- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText {
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        Games * game = [[Games alloc] init];
        NSArray * temp = [game comingSoonWithPlatform:@"pc" header:[game gameHeader] parseLink:[game gameComingSoonListLinkWithPlatform:@"pc"]];
        self.searchArray = [temp valueForKey:@"results"];
        [self.tableView reloadData];
    });
}

我究竟做错了什么？如果我在搜索栏中再输入一个词，或者如果我点击取消按钮，它会刷新并且数据会出现在 tableview 中。

Answer 1

您正在从主线程创建后台线程，在进行任何处理后，您需要切换到主线程以更新 UI。

例如，你可以在下面的方法中做你的编码工作——

- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
{
    // [activityIndicator startAnimating];
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

        // do your background code here
        Games * game = [[Games alloc] init];
        NSArray * temp = [game comingSoonWithPlatform:@"pc" header:[game gameHeader] parseLink:[game gameComingSoonListLinkWithPlatform:@"pc"]];
        self.searchArray = [temp valueForKey:@"results"];

        dispatch_sync(dispatch_get_main_queue(), ^{
            // you are now on the main queue again, update ui here  
        //[activityIndicator stopAnimating];
        [self.tableView reloadData];
        });
    });
}