I created a new project "Single View Application" and designed the mainView with Storyboard. My main view contains a UIButton that opens the camera, the camera scans barcode and automatically goes to a website. Now I created a webView programmatically so that website can open and also created a UIButton inside the webView. Now I want that UIButton to act as home botton and return to mainview. I am unable to do that, please help.
ViewController.m code: http://cl.ly/FKj8
My storyboard looks like:
You really should look into the View Controller Programming Guide -- by switching around the contents of a single view controller, you're making a lot of extra work for yourself with little benefit. By using multiple view controllers when you want to have different "screens" in your app, you can take advantage of storyboarding for easier development, and you automatically get better memory management (read: less potential for crashes), too.
However, to more directly answer your question... if you're putting the WebView into the view hierarchy with [self.view addSubview:webView], you can remove it with [webView removeFromSuperview]. (This means you'll have to keep a reference to the WebView around so you can refer to it when you want to dismiss it.)
I also noticed in the code you posted to cl.ly an unrelated method -deviceModel which uses uname() to get device information. This is a bad idea, for two reasons:
uname() isn't guaranteed to do something useful on an iOS device (even if it currently does). Use the UIDevice class instead if you need this kind of info, or...
Generally, you don't want to test for the device name to enable functionality in your app; instead, you should test for the capabilities you need. (For example, if you look for a device name starting with "iPhone 4" to test for a Retina display, you'll miss the 4th-generation iPod touch, and the iPhone-5-or-whatever-they-call-what's-next. Instead, use the UIScreen class.)
Related
I'm working on an app right now where a tap will be handled identically on the iPhone as on the iPad. I don't have an iPhone, so I'm using the simulator to test for now. I thought I could simply click with my mouse on the screen if the simulator to simulate taps, but that doesn't seem to work.
So I had the thought that maybe the problem was that I started with iPad and created the iPhone interface later (although the project itself was generic from the start).
I copied the gesture recognizers (tap and two swipes) from the storyboard for the iPad and pasted them into the storyboard for the iPhone. I didn't think this was going to work, but I was hopeful that's all I would have to do. In any case, it seems like the same code should be able to be linked from both storyborad gesture recognizers.
When that didn't work, I hooked up the iPhone gesture recognizers using Control-drag just like I did with the iPad. This created new methods. Since the same code could be used, I thought I'd simply call the other:
- (IBAction)tapIphone:(UITapGestureRecognizer *)sender {
[self tapIpad:sender];
}
- (IBAction)tapIpad:(UITapGestureRecognizer *)sender {
omitted code
}
That didn't work either. So next I tried copy/pasting the code from the iPad method to the iPhone method. It still didn't work.
So now I'm wondering if maybe I don't know how to test taps properly on the iPhone simulator. What else could I have missed?
It seems clear that the tapIphone method is not being called at all. You can work that out by adding #NSLog("tapIphone") in the method, see if it logs. In fact put these lines into their respective methods:
#NSLog("tapIphone");
#NSLog("tapIpad");
If tapIphone WAS getting called and the tapIpad method IS in the same class, the expected behaviour should have occurred.
Your first intuition, to copy and paste items from one storyboard to the other, is fine. However you lose all IBAction / IBOutlet connections when you do this (they don't carry over their links to and from the old storyboard, they just go), so you have to rewire them each time. Which is a bit of a pain when you are trying to adapt interface from one device for another. This does not mean that you have to create new code - it just means you have to CRTL-drag from each storyboard item onto the existing IBAction code item you want to reconnect to (you can achieve the same result by CTRL-dragging from the storyboard item to the relevant controlView storyboard icon, which will present you with a list of optional IBAction items to connect to). Same goes for any IBOutlet connections you want to replicate.
This is not an issue with the simulator, you just need to tweak your understanding of storyboard wiring.
I would not recommend your suggestion of separate IBAction methods as a way to handle different behaviours on different devices. This will lead to more wiring complexity which is irritating to debug. There are better ways to do that, for example by checking environment capabilities or using:
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
//iPhone code goes here
} else {
//ipad code goes here
}
I was using Xcode 4.1 and after upgrading to 4.2, things started to become out of date. I am using many examples from different books, such as Big Nerd Ranch Guides, which do not use Storyboards and the Windows-Based Application had been changed to "Empty" Application.
With these new changes, I feel like the books and tutorials I had been using to start have become outdated. In many of these examples, they say to write the methods and variables in the delegate header files for 4.1. With the new 4.2 Xcode, there is an AppDelegate and ViewController. Should I still be writing the methods and class members in the AppDelegate, or should I be now writing them in the Controller file?
I am confused. Does Apple now want us to create our controller and reference it through the delegate?
When your app is run, it creates an instance of UIApplication. You want to know things that only the UIApplication object knows (did we just get switched to the background? did we just open?) so you use the delegate pattern to get it. When you start a new project Apple starts you off with an already-assigned App Delegate. You can open up MainWindow.nib and inspect your App Delegate to see how it is connected to your UIApplication instance (File's Owner, in this case).
In general you only want to put code in there that has to do with the basic functionality of your app. Launch, quit, go to background and come to foreground are when you'll be doing things in the App Delegate.
Most everything else should go in your view controllers or model objects. Since 'delegate' is just a design pattern, your view controllers can be delegates of other objects. For example, if you present a UITableView, you will assign a view controller as it's delegate in order to respond to events such as selection and scrolling. Your app has many delegates, but it only has one App Delegate.
The AppDelegate is really just a "launcher" for your app. Ie: You shouldn't be writing much code in it at all.
If you're concerned with "set up" code, do it in your View Controller, under viewDidLoad.
Now,I gonna Develop an App ,which wants to switch from many different Views irregularly,also the views need to load large resources,AKA,it's hard to manage memory.Are there any good solustion?
PS：I created a ViewController as RootViewController,and When a button was Touch,run the code as
"ViewController=newController"
.The problem came,The new View loaded wrong way,it rotate so that couldn't show in a correct way.
I google for the solution,some one said ,I should replace the rootViewController,just like that,
[UIApplication sharedApplication].delegate.window.rootViewController=newController;
But I can't get/set the rootViewController in other class though it's a singleton.
Why not having a class that handles all the view switches ?
This article describes an architecture that might be helpfull: http://www.mikeziray.com/2010/01/27/handling-your-initial-view-controllers-for-iphone/comment-page-1/#comment-607
I couldn't find a good answer anywhere to this. I am using a UINavigationController for my iPhone app, with everything is generated programmatically, nothing in Interface Builder. I am trying to port my app to iPad, using a UISplitViewController and my existing UINavigationController, but I am not sure where I should have the logic of my program separating the view controllers for iPhone or iPad.
Do I set up my main file to use a different app delegate or do I use the same app delegate and have the user interface conditionally set up within it?
Besides this, whenever I try to compile my app on the simulator it does not recognize the UISplitViewController or even the condition in which I check if the class exists.
Can please someone put me in the right direction, remembering that I am not using any xibs?
If you want to see an example of a completely programmatic iPhone / iPad interface that uses a split view, you can download the source code of my application Molecules.
Within that application, I use one application delegate, but I set up the interface differently depending on which user interface idiom is present (iPad or iPhone). For the iPhone, I instantiate a root view controller which manages the appropriate interface for that device. For the iPad, I first create a UISplitViewController and attach it to the root window, then create my iPad-specific root view controller and place it as the detail view of the split view controller (with a navigation controller that I use for item selection as the left-hand controller for the split view).
Again, I recommend looking at that application project to see how I set this up programmatically. The code's available under a BSD license, so you can copy and paste this into your own application if you'd like.
As far as the compilation errors you're getting, you will need to migrate your application target to be a universal application using the "Upgrade Current Target for iPad" menu option. Once that has completed, set your build SDK to 3.2. Go to your application's build settings and set its Deployment Target to the earliest OS you want to support with your application (with 3.0 being the farthest back you can go).
Finally, you will need to weak-link UIKit. For how to do that, see my answer here. Weak linking of frameworks is no longer necessary if you are building using the iOS 4.2 or later SDK. Simply check for the presence of the appropriate classes at runtime by seeing if their +class method returns nil.
So I'm trying to use a UITableViewController (let's call it homeView) in my iPhone application to display a simple table with only a few rows of text which are loaded from an NSArray in the controller. I want to display the table in the grouped style in a subview of a subview (let's call it subSubView) of my main controller. When I try the following: [subSubView addSubview:homeView.view], my app crashes on launch. However, when I allocate the object without adding it to any views, it launches fine.
What's the best way (or rather a working way) to display the table generated by my UITableViewController?
There isn't enough to tell for sure what is going on, but if I had to guess I would think that you probably aren't retaining homeView. Normally I would say that as a comment to your question, since it is not really an answer, but I have a completely separate answer:
Just use a UITableView, not a UITableViewController. Instead of trying to embed a controller within a controller (which is quite difficult since Apple doesn't expose the necessary tools to actually modify the view controller hierarchy), just make the VC you are writing support the appropriate delegate/dataSource methods and directly create the view.
While it might make some logical sense to try to embed VCs inside of each other, with the exception of the builtin container VCs (UINavigationController, UITabBarController) it Really Doesn't Work™. The technical reason for this is that internally some of the event routing and messaging depends on parentViewController being correct, but since you can't set it (setParentViewController: is private) tons of latent bugs in UIKit start rearing their head. The internal collection classes can set the parentViewController correctly, so everything works right.
Also, one last thing. In your question you named your view controller homeView. Please, please on't do that. A view controller and a view are separate things, call it homeViewController. Aside from the fact that a lot of new iPhone developers get confused about what the distinction is, there is nothing more aggravating then tracing through someone else's code and realizing that something you are assuming is one type is another.