iphone 疑问： 内存管理经常碰到的问题

1：问题1：使用 removeFromSuperview   时，retainCount的问题

                NSLog(@"before remove the cameraViewController's retaincount is %d",[cameraViewController retainCount]);

                                 [cameraViewController.view removeFromSuperview];

                NSLog(@"after remove the cameraViewController's retaincount is %d",[cameraViewController retainCount]);

       

 以上代码输出：

          before remove the cameraViewController's retaincount is 2

         before remove the cameraViewController's retaincount is 4

问题疑惑：为什么cameraViewController的retainCount的值会从2变到4呢。 

 

 求解答： 

 

 

 

2:问题1: 两个nslog之间没有任何代码，但是这第一个nslog的%d的值为2，第二个nslog的%d的值为3，太神奇了，不知道为什么？

 

                                             NSLog(@"before remove the cameraViewController's retaincount is %d",[cameraViewController retainCount]);

                                             NSLog(@"after remove the cameraViewController's retaincount is %d",[cameraViewController retainCount]);

 

 3:  下面这段代码的执行结果很让人意外，请看

   

cameraViewController = nil;

cameraViewController = [[IPhoneConnectTestViewController alloc] initWithNibName:@"IPhoneConnectTestViewController" bundle:nil];

                NSLog(@"after alloc the cameraViewController's retaincount is %d",[cameraViewController retainCount]);

[cameraViewController loadCamera: (CameraDO *)obj];

                NSLog(@"after loadCamera the cameraViewController's retaincount is %d",[cameraViewController retainCount]);

                self.title = camera.cameraName;

                [self.view addSubview:cameraViewController.view];

                NSLog(@"after addSubview the cameraViewController's retaincount is %d",[cameraViewController retainCount]); 

 

 

输出结果是：

2011-11-11 16:23:53.065 vsstoo[8755:11f03] after alloc the cameraViewController's retaincount is 1

2011-11-11 16:23:53.066 vsstoo[8755:11f03] after loadCamera the cameraViewController's retaincount is 1

2011-11-11 16:23:53.070 vsstoo[8755:11f03] after addSubview the cameraViewController's retaincount is 3

2011-11-11 16:23:53:250 vsstoo[8755:11f03] socket:0x849bf80 didConnectToHost:121.205.90.83 port:30016

 

[swscaler @ 0x9184c00]No accelerated colorspace conversion found. 

 

 不是道为什么吗？

 

 

转载于:https://www.cnblogs.com/85538649/archive/2011/11/11/2245741.html