Iphone 从';这不是主线吗?
我的想法是让一个视图在幕后计算时显示给用户。这是一个高度为30px的视图,包含一个UIActivityIndicatorView和一个UILabel,显示当前正在计算的内容 我试图通过使用具有以下方法的ActivityHandler来实现它:Iphone 从';这不是主线吗?,iphone,cocoa,cocoa-touch,multithreading,Iphone,Cocoa,Cocoa Touch,Multithreading,我的想法是让一个视图在幕后计算时显示给用户。这是一个高度为30px的视图,包含一个UIActivityIndicatorView和一个UILabel,显示当前正在计算的内容 我试图通过使用具有以下方法的ActivityHandler来实现它: - (void)newActivityStarted{ [self performSelectorOnMainThread:@selector(showActivityViewer) withObject:nil waitUntilDone:NO]
- (void)newActivityStarted{
[self performSelectorOnMainThread:@selector(showActivityViewer) withObject:nil waitUntilDone:NO];
}
- (void)activityStopped{
[self performSelectorOnMainThread:@selector(hideActivityViewer) withObject:nil waitUntilDone:NO];
}
- (void)changeInfoText:(NSString*)infoText{
[activityView.infoLabel performSelectorOnMainThread:@selector(setText:) withObject:infoText waitUntilDone:NO];
}
以下是在主线程上调用的方法:
-(void)hideActivityViewer{
CGContextRef context = UIGraphicsGetCurrentContext();
[UIView beginAnimations:nil context:context];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
[UIView setAnimationDuration:0.2];
[UIView setAnimationDelegate: self];
[UIView setAnimationDidStopSelector:@selector(closeActivityViewer:finished:context:)];
[activityView setFrame:CGRectMake(320, 10, 320, 30)];
[UIView commitAnimations];
}
-(void)closeActivityViewer:(NSString*)id finished:(BOOL)finished context:(id)context{
[activityView removeFromSuperview];
[activityView release];
activityView = nil;
}
-(void)showActivityViewer{
activityView = [[BCActivityView alloc] initWithFrame:CGRectMake(320, 10, 320, 30)];
[activityView.infoLabel setText:NSLocalizedString(@"WorkInProgressKey",nil)];
[[(MyAppDelegate*)[[UIApplication sharedApplication] delegate] window] addSubview: activityView];
CGContextRef context = UIGraphicsGetCurrentContext();
[UIView beginAnimations:nil context:context];
[UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
[UIView setAnimationDuration:0.2];
[activityView setFrame:CGRectMake(0, 10, 320, 30)];
[UIView commitAnimations];
}
正在计算一些耗时数据的后台线程调用newActivityStarted、activityStopped和changeInfoText方法
耗时的线程将按如下方式打开:
NSInvocationOperation* operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(calculateData) object:nil];
[[[NSOperationQueue new] autorelease] addOperation:operation];
[operation release];
-(void) calculateData{
[[ActivityIndicatorHandler instance] newActivityStarted];
[[ActivityIndicatorHandler instance] changeInfoText:NSLocalizedString(@"InitializingForecastKey", nil)];
//Do something time consuming
[[ActivityIndicatorHandler instance] activityStopped];
}
计算如下所示:
NSInvocationOperation* operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(calculateData) object:nil];
[[[NSOperationQueue new] autorelease] addOperation:operation];
[operation release];
-(void) calculateData{
[[ActivityIndicatorHandler instance] newActivityStarted];
[[ActivityIndicatorHandler instance] changeInfoText:NSLocalizedString(@"InitializingForecastKey", nil)];
//Do something time consuming
[[ActivityIndicatorHandler instance] activityStopped];
}
其效果是,在完成整个计算后,将显示并隐藏“活动”视图。我希望GUI显示视图,并在后台进行计算时负责用户交互。但是,即使我在计算中有一个断点,在计算线程完成其工作之前,视图将不可用,并且活动视图也不会显示。。。我不知道怎么了
有人有想法吗?您是否尝试通过执行以下操作来调用计算:
[self performSelectorInBackground:@selector(calculateData) withObject:nil];
在其他方法中,可能是您的应用程序委托,在初始值设定项中设置本地队列:
NSOperaionQueue* aQueue = [[[NSOperationQueue alloc] init] retain]; //release in dealloc
ActivityHandler* myHandler [[[ActivityHandler alloc] init] retain]; //release in dealloc
Have a method to add ops to the queue:
-(void)queueOperation:(NSInvocationOperation*)anOp;
{
[aQueue addOperation:anOp];
}
-(IBAction*)startCalcs:(id)sender;
{
[self queueOperation:[myHandler myOperation]];
}
我想你需要考虑PrimeStudioOnMeNothOn:Objist:WaistunLeDe:方法
不需要在OLAC之后保留消息。这只会造成内存泄漏。当然会。我更改了答案,使myHandler成为应用程序代理的ivar,更好地显示我的意图。感谢您提供详细的答案。如果我比较我们的解决方案,唯一的区别似乎是,您的队列由局部变量引用。我将尝试这个解决方案,然后回来告诉我的结果。但是这会改变什么呢?顺便问一下,为什么在alloc/init之后保留队列和处理程序?我试过了,但遗憾的是它没有改变任何东西。这是同样的现象。计算完成后,该视图将出现并立即消失。