UISegmentedControl embedded in a UINavigationBar/Item

问题

I would like to embed a UISegmentedControl somewhere in my UINavigationControllers topbar.

It is no problem embedding it in a UIBarButtonItem and setting it as the left or right barButtonItem.

I can understand this approach when dealing with the screen real-estate of an iPhone. I am, however, doing this in a Popover on an iPad and there is "lots" of vertical space available in the topbar. If I add the segmentedControl as a left or right barButtonItem it gets scaled down so that I can not see the text on my segment button, it gets to be the width of a "Done" button etc. If I try to add it to the navigationItem TitleView it will show up all the way to the right and still scaled down more than my 3 segment control with text can display.

How would I go about adding a UISegmentedControl to the center of the UINavigationController that wraps my popovers content.

Hope someone can help me out:) thanks in advance.

回答1:

Why would you need to put the control in the popover title bar? iPad has much more screen real estate to consider putting it into the view below.

-- EDIT --

I tried it myself and it works. Here is the code setting up the popover controller:

- (IBAction) showPopover: (id) sender
{
    TestController *testController = [[TestController alloc] initWithStyle: UITableViewStylePlain];
    UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController: testController];
    UIPopoverController *controller = [[UIPopoverController alloc] initWithContentViewController: navController];
    [controller presentPopoverFromBarButtonItem: sender permittedArrowDirections: UIPopoverArrowDirectionAny animated: YES];
    controller.delegate = self;
    [testController release];
    [navController release];
}

Here is the implementation of TestController:

- (id) initWithStyle: (UITableViewStyle) style
{
    if ( (self = [super initWithStyle: style]) ) {
        UISegmentedControl *ctrl = [[UISegmentedControl alloc] initWithFrame: CGRectZero];
        ctrl.segmentedControlStyle = UISegmentedControlStyleBar;
        [ctrl insertSegmentWithTitle: @"One" atIndex: 0 animated: NO];
        [ctrl insertSegmentWithTitle: @"Two" atIndex: 0 animated: NO];
        [ctrl insertSegmentWithTitle: @"Three" atIndex: 0 animated: NO];
        [ctrl sizeToFit];
        // Any of the following produces the expected result:
        self.navigationItem.titleView = ctrl;
        //self.navigationItem.leftBarButtonItem = [[[UIBarButtonItem alloc] initWithCustomView: ctrl] autorelease];
        [ctrl release];
    }
    return self;
}

Here is the result: