使用块时"与整数转换不兼容"

Question

我正在为下面的代码收到这些警告.任何想法如何解决？谢谢你的帮助.

• 类型说明符缺失,默认为'int'
• 指向整数转换的指针不兼容,使用'void*'类型的表达式初始化'int';
• 未使用的变量'mymoviePlayerController'

重要的是 "__block mymoviePlayerController = nil;

- (void) moviePlaybackCompleteLightBox:(NSNotification*) notification {

        MPMoviePlayerController *mymoviePlayerController = [notification object];  
        [[NSNotificationCenter defaultCenter] removeObserver:self  
                                                        name:MPMoviePlayerPlaybackDidFinishNotification  
                                                      object:mymoviePlayerController]; 


        // movie fadein transition ====================
        self.moviePlayerController.view.alpha = 1;

        [UIView animateWithDuration:0.3f delay:0.0 options:UIViewAnimationCurveEaseOut
                         animations:^{
                             self.moviePlayerController.view.alpha = 0;   
                         }
                         completion:^(BOOL finished) { 
                             [mymoviePlayerController stop];
                             [mymoviePlayerController.view removeFromSuperview];
                             __block mymoviePlayerController = nil;

                         }];

    }

Answer 1

__block在声明变量时使用,而不是在为其赋值时使用.所以编译器将以下行视为变量声明,这是错误的:

 __block mymoviePlayerController = nil; 

声明变量时应该使用__block属性:

__block MPMoviePlayerController *mymoviePlayerController = [notification object];

PS为什么你在这里使用__block？看起来在这种情况下你不需要它