ios 卡顿，push多次同一个页面

场景：快速多次点击cell跳转到另一个页面，另一个页面被push多次。

原因：push后的页面有耗时操作或者刚好push到另一个页面时，另一个页面正好在reloadData卡住主线程。造成点击cell时卡住了。

解决方法：

重写导航控制器的push方法。

#import "DemoNavViewController.h"  
  
  
@interface DemoNavViewController () <UINavigationControllerDelegate>  
// 记录push标志  
@property (nonatomic, getter=isPushing) BOOL pushing;  
  
@end  
  
  
@implementation DemoNavViewController  
  
  
- (void)viewDidLoad {  
    [super viewDidLoad];  
      
    self.delegate = self;  
}  
  
  
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated  
{  
    if (self.pushing == YES) {  
        NSLog(@"被拦截");  
        return;  
    } else {  
        NSLog(@"push");  
        self.pushing = YES;  
    }  
      
    [super pushViewController:viewController animated:animated];  
}  
  
  
#pragma mark - UINavigationControllerDelegate  
-(void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated  
{  
    self.pushing = NO;  
}  
  
  
@end