带有提示和活动指示符的UINavigationItem

Question

我想知道Apple如何在标题上方实现包含活动指示符的UINavigationItem(参见下图).Apple的私有API是否允许这样做？如果没有,如何在应用程序中复制.

带有提示和活动指示符的UINavigationItem http://img218.imageshack.us/img218/8819/img0133g.png

谢谢!

Answer 1

使用此代码,我得到的截图与截图完全相同:

 UIView                      *viewContainingSpinner;
    UIActivityIndicatorView     *activityIndicatorView;
    UIBarButtonItem             *activityButtonItem;
    UIBarButtonItem             *rightBarButtonItem;


    // Configuring the title and the prompt title of the navigation bar
    [self.navigationItem setTitle:@"MobileMe"];
    [self.navigationItem setPrompt:@"Vérification du compte MobileMe"];

    // We will create a UIBarButtonItem that has a custom view (viewContainingSpinner).
    // A subview of viewContainingSpinner will be a UIActivityIndicatorView (activityIndicatorView)
    // We need to have this "intermediate" view to position the spinner at the right position (the UIBarButtonItem ignores the origin and height of its custom view)
    viewContainingSpinner = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 60, 85)];
    activityIndicatorView = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(20, 0, 20, 20)];
    [viewContainingSpinner addSubview:activityIndicatorView];
    [activityIndicatorView startAnimating];
    [activityIndicatorView release];

    activityButtonItem = [[UIBarButtonItem alloc] initWithCustomView:viewContainingSpinner];
    self.navigationItem.leftBarButtonItem = activityButtonItem;
    [viewContainingSpinner release];
    [activityButtonItem release];

    // Finally, configuring the right button
    rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Enregistrer" style:UIBarButtonItemStylePlain target:nil action:nil];
    [rightBarButtonItem setEnabled:NO];
    self.navigationItem.rightBarButtonItem = rightBarButtonItem;
    [rightBarButtonItem release];

PS:在实际应用程序中,我建议不要在代码中使用本地化字符串."Vérification"这个词的é可能会给你带来麻烦.看看NSLocalizedString方法.