线程是否会干扰程序的正常工作行为？
我有一个视图控制器，它是 UIViewController 的子类，其中包含表视图，并且表视图中的每一行都链接到不同的 xml url。我创建了一个解析器类，它是 NSOperation 的子类，并实现了在选择每一行时解析 XML 文件的方法，
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
[self performSelectorOnMainThread:@selector(pushView) withObject:nil waitUntilDone:NO];
[self performSelectorInBackground:@selector(parseOperation:) withObject:indexPath];
}
-(void)pushView{
detailView = [[viewDetailsController alloc] initWithNibName:@"viewDetailsController" bundle:nil];
[self.navigationController pushViewController:detailView animated:YES];
}
-(void)parseOperation:(NSIndexPath *)indexPath{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
self.queue = [[NSOperationQueue alloc] init];
parserClass *parser = [[parserClass alloc] initWithParseUrl:[[self.arrayOfUrls objectAtIndex:indexPath.row]delegate:self];
[queue addOperation:parser];
[parser release];
[pool release];
}
解析器工作得很好，但在其自定义委托方法中，我调用了将视图控制器推送到导航控制器堆栈的顶部，视图控制器正确初始化，但新的视图控制器未推送到屏幕中。 我不知道为什么这不起作用。
I have a view controller that is sub class of UIViewController which has table view into it and each rows in table view is linked to distinct xml url. I made a parser class that is sub class of NSOperation and implemented methods to parse the XML file on selection of each row as,
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
[self performSelectorOnMainThread:@selector(pushView) withObject:nil waitUntilDone:NO];
[self performSelectorInBackground:@selector(parseOperation:) withObject:indexPath];
}
-(void)pushView{
detailView = [[viewDetailsController alloc] initWithNibName:@"viewDetailsController" bundle:nil];
[self.navigationController pushViewController:detailView animated:YES];
}
-(void)parseOperation:(NSIndexPath *)indexPath{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
self.queue = [[NSOperationQueue alloc] init];
parserClass *parser = [[parserClass alloc] initWithParseUrl:[[self.arrayOfUrls objectAtIndex:indexPath.row]delegate:self];
[queue addOperation:parser];
[parser release];
[pool release];
}
Parser works great but in its custom delegate method I have called to push view controller on the top of the navigation controller stack, the view controller initializes correctly but the new view controller is not pushed into the screen.
I dont have any idea about why this is not working.
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（2）
所有 UI 调用都必须从主线程进行，其中可能包括分配/初始化 UI 类。听起来您在自定义委托方法中违反了该规则。
All UI calls must be made from the main thread, which may include allocating/initializing UI classes. It sounds like you are breaking that rule in your custom delegate method.
您应该仅从主线程使用 UI。
所以在你的委托方法中你必须添加类似的东西
或者你可以直接调用tableView的方法：
You should work with UI only from the main thread.
So in your delegate method you have to add something like
Or you can call a method of tableView directly: