alertView不能自动隐藏——谈多线程执行延迟对应用程序的影响

当CommonAlert.m中的方法执行的快时，alertView的显示和消失是正常的。如下所示：

2013-01-24 23:31:59.978 点餐系统[5649:707] 进入OrderListViewController.m的-(IBAction)btnTaocanMenuClicked:(id)sender

2013-01-24 23:31:59.982 点餐系统[5649:707] 进入CommonAlert.m的startAlertView

2013-01-24 23:31:59.986 点餐系统[5649:5e0b] 进入CommonAlert.m的startAlertProcess

2013-01-24 23:31:59.989 点餐系统[5649:5f07] 进入CommonAlert.m的presentAlert

2013-01-24 23:31:59.995 点餐系统[5649:707] 进入OrderListViewController.m的-(void)ShowOrderMenu

2013-01-24 23:31:59.997 点餐系统[5649:707] 进入OrderListViewController.m的-(void)clearSmallOrderList:(NSString *)code

2013-01-24 23:32:00.003 点餐系统[5649:707] 进入OrderListViewController.m的-(void)getFoodByType:(NSString *)typeCode Type:(NSInteger) type PackageId:(NSString *)packageid

2013-01-24 23:32:00.042 点餐系统[5649:5f07] 进入JKCustomAlert.m的- (void) show

2013-01-24 23:32:00.054 点餐系统[5649:5f07] 进入JKCustomAlert.m的- (void) layoutSubviews

2013-01-24 23:32:00.063 点餐系统[5649:5f07] 进入JKCustomAlert.m的- (void) layoutSubviews

2013-01-24 23:32:00.066 点餐系统[5649:5f07] 进入JKCustomAlert.m的- (void)drawRect:(CGRect)rect      

2013-01-24 23:32:00.085 点餐系统[5649:707] 进入OrderListViewController.m的-(void)parserTaocan:(NSMutableArray *)foodlist

2013-01-24 23:32:00.089 点餐系统[5649:707] smallPic:

2013-01-24 23:32:00.093 点餐系统[5649:707] 进入OrderListViewController.m的-(NSString *)documentsFolder

2013-01-24 23:32:00.101 点餐系统[5649:707] smallPic:

2013-01-24 23:32:00.105 点餐系统[5649:707] 进入OrderListViewController.m的-(NSString *)documentsFolder

2013-01-24 23:32:00.134 点餐系统[5649:707] smallPic:

2013-01-24 23:32:00.137 点餐系统[5649:707] 进入OrderListViewController.m的-(NSString *)documentsFolder

2013-01-24 23:32:00.148 点餐系统[5649:707] 进入OrderListViewController.m的-(void)animationOglFlip

2013-01-24 23:32:00.151 点餐系统[5649:707] 进入CommonAlert.m的dismissAlertView

2013-01-24 23:32:00.739 点餐系统[5649:707] 进入JKCustomAlert.m的- (void)dealloc 

当CommonAlert.m中的方法执行的慢时，alertView的就无法正常消失。因为，当我们调用dismissAlertView方法时，alertView还没有绘制出来呢！而当alertView绘制出来时，dismissAlertView方法早已错过。

2013-01-24 23:35:03.687 点餐系统[5649:707] 进入OrderListViewController.m的-(IBAction)btnTaocanMenuClicked:(id)sender

2013-01-24 23:35:03.690 点餐系统[5649:707] 进入CommonAlert.m的startAlertView

2013-01-24 23:35:03.693 点餐系统[5649:442f] 进入CommonAlert.m的startAlertProcess

2013-01-24 23:35:03.696 点餐系统[5649:690f] 进入CommonAlert.m的presentAlert

2013-01-24 23:35:03.702 点餐系统[5649:707] 进入OrderListViewController.m的-(void)ShowOrderMenu

2013-01-24 23:35:03.704 点餐系统[5649:707] 进入OrderListViewController.m的-(void)clearSmallOrderList:(NSString *)code

2013-01-24 23:35:03.709 点餐系统[5649:707] 进入OrderListViewController.m的-(void)getFoodByType:(NSString *)typeCode Type:(NSInteger) type PackageId:(NSString *)packageid

2013-01-24 23:35:03.746 点餐系统[5649:707] 进入OrderListViewController.m的-(void)parserTaocan:(NSMutableArray *)foodlist

2013-01-24 23:35:03.748 点餐系统[5649:707] smallPic:

2013-01-24 23:35:03.751 点餐系统[5649:707] 进入OrderListViewController.m的-(NSString *)documentsFolder

2013-01-24 23:35:03.759 点餐系统[5649:707] smallPic:

2013-01-24 23:35:03.763 点餐系统[5649:707] 进入OrderListViewController.m的-(NSString *)documentsFolder

2013-01-24 23:35:03.770 点餐系统[5649:707] smallPic:

2013-01-24 23:35:03.773 点餐系统[5649:707] 进入OrderListViewController.m的-(NSString *)documentsFolder

2013-01-24 23:35:03.780 点餐系统[5649:707] 进入OrderListViewController.m的-(void)animationOglFlip

2013-01-24 23:35:03.783 点餐系统[5649:707] 进入CommonAlert.m的dismissAlertView

2013-01-24 23:35:03.793 点餐系统[5649:690f] 进入JKCustomAlert.m的- (void) show

2013-01-24 23:35:03.805 点餐系统[5649:690f] 进入JKCustomAlert.m的- (void) layoutSubviews

2013-01-24 23:35:03.817 点餐系统[5649:690f] 进入JKCustomAlert.m的- (void) layoutSubviews

2013-01-24 23:35:03.824 点餐系统[5649:690f] 进入JKCustomAlert.m的- (void)drawRect:(CGRect)rect

解决方案： 在执行dismissAlertView前让线程暂停0.5秒，如：    [NSThreadsleepForTimeInterval:0.5];