Same WebView on every view

问题:

Basically i have a WebView on SecondViewController and I wish for the WebView to be visible on every view like a tab bar and fully controllable on each view.

Please note the WebView will be on a webpage with a online slideshow so I cannot simply reload on each view

Also in the SecondViewController I have

- (void)webViewDidFinishLoad:(UIWebView *)YouTubePlayer {

回答1:

I'd just set up a singleton UIWebView and add it to each view-controller-view when that view controller is about to become visible. Here's one way to do it:

//.h

@interface SharedWebView : UIWebView
{
}

+ (SharedWebView*) shared;

@end

//.m

SharedWebView* g_sharedWebView;

@implementation SharedWebView


+ (SharedWebView*) shared 
{
    if ( g_sharedWebView == nil )
    {
        g_sharedWebView = [[SharedWebView alloc] init];

        // ... any other intialization you want to do
    }

    return g_sharedWebView;
}

@end


// in your view controller(s)

@property (readonly) UIWebView* webView

- (UIWebView*) webView
{
    return [SharedWebView shared];
}

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

    [self.view addSubview: self.webView ];
    self.webView.frame = CGRectMake(10, 10, 300, 300);

    // want to re-set the delegate?
    // self.webView.delegate = self;
}

回答2:

I would suggest adding the webView on you window after the you add the tabbarcontroller.view just like:

[window addSubview:tabbarController.view];
[window addSubview:webview];
[window makeKeyAndVisible];

and initially make don't make it visible. You should handle all the webview related methods in the app delegate. Now whenever you don't need it you can hide it by calling the methods your wrote in app delegate from your view controllers.

Hope this helps.

回答3:

The simplest approach is to just make all of your view controllers aware of this extra view (make the view available through a singleton PinnedViewController or whatever). During each view controller's -viewWillAppear, just do this:

[self addSubview:[[PinnedViewController sharedController] view]];

This will move the view to whoever is currently active (making a view your subview automatically removes you from your old hierarchy).

If that is cumbersome or otherwise unworkable, there are two other options. First, you can subclass UITabViewController (I assume that's what you're using here from your question), and inject your extra view (resizing the content view to make room). This is undocumented and unsupported, so take heed. But it's not incredibly difficult if you don't do too many other fancy tricks.

The other tricky solution is to create a second UIWindow that you float over the main UIWindow (or resize the main UIWindow to make room for it). This is only semi-documented and is also not really supported. But this approach can work if you're trying to put the extra view below the tabbar for instance.

But if your system is simple enough, I recommend just letting your view controllers all manage the pinned view manually. You'll save a lot of code spelunking that way, and you won't have to rely on any undocumented internal view hierarchies.

回答4:

Sounds like you try to put views on top of this view but not modal. There was this blog entry I once saw that described how you would do something like this. I think it should apply also for your case: semi-modal-transparent-dialogs-on-the-iphone

回答5:

In iOS UIViewControllers are expected to manage an entire "screen" worth of content so it's not normal to try to share a single view across many view controllers. Trying to have UIViewControllers whose views only manage part of their window is problematic and will result in unexpected behavior as UIKit will not send messages like -viewWillAppear to all view controllers with visible views. Instead you would normally create a single UIViewController whose view includes that web view and whatever other views compose your tab like interface. Alternately you could have a hierarchy of many view controllers and add a single web view as a subview of all of them. You would then pull your web view delegate behavior out into some non-UIViewController controller class to manage the behavior of the web view.

回答6:

You can have all your views take up a portion of the screen and have your UIWebView take up the rest. The logic for switching between the other views should remain the same.

For example, in your viewDidLoad method for your UIViewControllers, you could have something like:

self.view.frame = CGRectMake(0, 100, 320, 380);

And in your (say) AppDelegate, you would have your normal call to show the main UIViewController (in your case, it sounds like a UITabBarController?) and also have a call to add the UIWebView. Say, something like:

myWebView.view.frame = CGRectMake(0, 0, 320, 100);

The view controllers and UIWebView would be independent of each other.

You see this pattern, I believe, with apps that have iAds. I've done something just like this with one of my free apps.

Hope this helps!

回答7:

I got the same effect by simply adding it to the navigationController itself(if you don't have one then just add it). works great for me in one of my apps.

回答8:

Could you not use two webviews on your application and simply change the uppermost webview with your more dynamic content?