Question

我有一个表格视图，当按下其中一个项目时会显示一个新视图。问题是新视图的navigationItem属性未显示。相反，前一个视图（表格视图）导航项似乎显示（表格视图的导航栏动画未更改）。

这是推送新视图的印刷机处理程序：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
  NSLog(@"--- showing asset picker");
  ELCAssetTablePicker *picker = [[ELCAssetTablePicker alloc] initWithNibName:@"ELCAssetTablePicker" bundle: nil];
    picker.parent = self;

  picker.assetGroup = [self.assetGroups objectAtIndex:indexPath.row];
  //[picker.assetGroup setAssetsFilter:[ALAssetsFilter allPhotos]];
  [self.navigationController pushViewController:picker animated:YES];

  [picker release];
}

以下是推送视图的viewDidLoad方法（ELCAssetTablePicker），其中self.navigationItem的标题和按钮已更新：

- (void)viewDidLoad
{
  [super viewDidLoad];
  [self.tableView setSeparatorStyle:UITableViewCellSeparatorStyleNone];
  [self.tableView setAllowsSelection:NO];

  NSMutableArray *tempArray = [[NSMutableArray alloc] init];
  self.elcAssets = tempArray;
  [tempArray release];
  UINavigationItem* navigationItem = self.navigationItem;

  UIBarButtonItem *doneButtonItem = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(doneAction:)] autorelease];

  [navigationItem addBackBarButtonItemWithTitle:@"Back" forController:self];
  [navigationItem addRightBarButtonItem:doneButtonItem];
  [navigationItem setTitle:@"Loading..."];

  [self performSelectorInBackground:@selector(preparePhotos) withObject:nil];
}

为什么在将新视图推送到UINavigationController时，导航栏是否未更新？

Answer 1

让navigationItem全球化。据我所知，它的参考被杀了。为什么不使用简单的self.navigationItem。

- (void)viewDidLoad
{
  [super viewDidLoad];
  [self.tableView setSeparatorStyle:UITableViewCellSeparatorStyleNone];
  [self.tableView setAllowsSelection:NO];

  NSMutableArray *tempArray = [[NSMutableArray alloc] init];
  self.elcAssets = tempArray;
  [tempArray release];

  UIBarButtonItem *doneButtonItem = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(doneAction:)] autorelease];

  [self.navigationItem addBackBarButtonItemWithTitle:@"Back" forController:self];
  [self.navigationItem addRightBarButtonItem:doneButtonItem];
  [self.navigationItem setTitle:@"Loading..."];

  [self performSelectorInBackground:@selector(preparePhotos) withObject:nil];
}

调用pushViewController后，UINavigationController显示错误的navigationItem

1 个答案: