这是我在ViewController.m文件中的代码,

- (void)viewDidAppear:(BOOL)animated
 {
   [super viewDidAppear:animated];

   NSLog(@"%f",[self usedMemory]);
   NSMutableArray *array= [[NSMutableArray alloc]init];
   for (int i = 0; i < 100; i++) {
      NSMutableData *data = [NSMutableData dataWithLength:10000];
       [array addObject:data];
   }
   NSLog(@"%f",[self usedMemory]);

   for (int i = 0; i < 100; i++) {
       [array removeObjectAtIndex:0];
   }
   NSLog(@"%f",[self usedMemory]);
}


这是usedMemory方法:

- (double)usedMemory
{
    task_basic_info_data_t taskInfo;

    mach_msg_type_number_t infoCount = TASK_BASIC_INFO_COUNT;

    kern_return_t kernReturn = task_info(mach_task_self(),

                                     TASK_BASIC_INFO,

                                     (task_info_t)&taskInfo,

                                     &infoCount);
    if (kernReturn != KERN_SUCCESS

       )
    {
        return NSNotFound;
    }
    return taskInfo.resident_size / 1024.0 / 1024.0;
}


结果如下:

2015-01-26 22:39:00.058 audio_memory_test[9050:874963] 25.011719
2015-01-26 22:39:00.060 audio_memory_test[9050:874963] 26.312500
2015-01-26 22:39:00.060 audio_memory_test[9050:874963] 26.312500


删除阵列中的对象时,为什么没有释放内存? removeObjectAtIndex方法做了什么?如何释放此记忆?

最佳答案

在最后一个循环之后调用[self usedMemory]时,对象仍保留在内存中。它们所属的自动释放池尚未耗尽。当您离开源代码的范围并且系统再次控制时,通常会发生这种情况。

07-24 16:15