Question

我正在使用UISplitViewController，当加载Master VC（UITableViewController）并按下表格单元格时，它会创建Detail VC（带有两个UIWebViews的UIViewController）：


@implementation MasterVC

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    UIViewController  *detailViewController = nil;
    DetailVC *newDetailViewController = [[DetailVC alloc] initWithNibName:@"DetailVC" bundle:nil];
    detailViewController = newDetailViewController;

    // Update the split view controller's view controllers array.
    NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, detailViewController, nil];
    splitViewController.viewControllers = viewControllers;
    [viewControllers release];

    [detailViewController release];
}

如果我模拟内存警告，则释放DetailVC（didReceiveMemoryWarning，viewDidUnload，dealloc被调用）但是我得到了一个“ - [UIView _invalidateSubviewCache]：发送到解除分配实例的消息”错误在MasterVC的行中我发布了viewControllers，因为它试图加载由于内存警告而释放的detailViewController（DetailVC），因此有意义。为什么它必须释放细节vc，因为它的视图是显示的，我不完全理解。

现在，如果不是在didSelectRowAtIndexPath中释放detailViewController，而是在viewWillDisappear中释放它，一切正常：


@implementation MasterVC

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    UIViewController  *detailViewController = nil;
    DetailVC *newDetailViewController = [[DetailVC alloc] initWithNibName:@"DetailVC" bundle:nil];
    detailViewController = newDetailViewController;

    // Update the split view controller's view controllers array.
    NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, detailViewController, nil];
    splitViewController.viewControllers = viewControllers;
    [viewControllers release];

    // Released in viewWillDissapear   
    //[detailViewController release];
}

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

    MyAppDelegate *delegate = [[UIApplication sharedApplication] delegate];
    // Retrieve the detail vc and release it-[UIView _invalidateSubviewCache]: message sent to deallocated instance
    [[delegate.splitViewController.viewControllers objectAtIndex:1] release];
}

对我来说，当主视图控制器消失时，释放详细视图控制器是有意义的，但是，它仍然看起来像是一个黑客（加上静态分析器抱怨不释放详细信息vc） '正确的地点）。还有其他更好的解决方法吗？

UISplitViewController - 处理内存警告

0 个答案: