I was helped here a while ago about loading images from an array, but would like to know the exact details please.
Where does the code go if my app will be as simple as images that load from an array depending on whether the user chose the next or previous button? Does it go in the View Controller class?
What do I need if I literally just need one view which displays a full screen image and the image gets changed depending on the user choice, like I mentioned above?
Thanks in advance
Regards
The view controller is responsible for controlling the view (receiving events from it, doing something then passing back data to it).
That said you can store your array in the view controller or in some other model class. Either way the view controller will be responsible for taking an image from this array and giving it to the view when it receives user input.
You just need to place a UIImageView in your view controller's view. Then assuming you're using IB you create an IBOutlet property in your controller to have a handle on this image view.
Then you need to get events from your user (either a button, or some other touch) and assign it to an IBAction that your controller can handle. When you handle the action you can remove the old image and assign a new image from your array to your UIImageView.
That's about as detailed as I can go given your current question. If you need more information please give more detail.
Related
I am trying to create a simple app and here is how it works:
When the user clicks the button "Picking", it'll show a tableview. And when the user selects a row in the table view, it will show the first view and display the data on the label.
I have 2 problems:
Every time I click the button "Picking", a new instance of the table view controller gets created; but does not reuse the existing one. How can I make it reuse the old one?
I want to pass the selected data to the root view. I tried by creating a segue to show the root view when user selects a cell and then passing the data on prepareForSegue method. But, I faced the above problem of memory leak. How do I pass the data between screens without leaking memory?
It sounds like you may be making a circular view hierarchy. When you tap on the cell in the table view, if you're pushing a new instance of the first VC, that is the wrong way to do it IMO.
Instead, you should pass the data back to the first VC then dismiss the second VC. Then, when you tap on the "Picking" button again, it's a new instance of the table view but your previous instance has already been removed from memory.
This allows for the smallest amount of memory to be used at any given time. When the table view controller isn't on the screen, it doesn't need to be in memory.
IMO, the best way to pass data up a navigation stack is to use a protocol and delegate. It's similar to how Objective-C protocols and delegates worked if you're familiar with that. Here is Apple's documentation on both. The delegate section is about 1/3 the way down the page.
https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Protocols.html
I am designing an iPhone application with a home page. This page has multiple buttons (6) that go to different things.
2 buttons are a simple view that just have some information and go back to the home screen. The next button opens up an email and I believe that will just be one view, so not a whole lot different than the other two.
Here is where it gets complicated. One button will take a picture, and another will select one from the library. Once that is done it will edit it and create an object that I will create. That object will be stored in an array, which will be opened by the last button one the home page and a UITableViewController will control that.
My first question is should I use a navigation based view controller or just a view controller that I can create myself? Or should I use something that I don't even know about?
Please Help!!! And if you help a sincere thank you!
EDIT:
Well i tried it my own way first and the only issue i'm having is this code
- (void) displayView:(int)intNewView {
NSLog(#"%i", intNewView);
[home.view removeFromSuperview];
Instructions *i = [[Instructions alloc]init];
instructions = i;
[self.view insertSubview:instructions.view atIndex:0];
}
It is in my SwitchClass, which controls the Main Window's view. I know it is working there because when it first runs the switch class directs it to the home screen. I know the method is being called because the console is displaying the NSLog thing, but it just won't switch.
Aside from the fact that you have 6 buttons, I would try and use a UITabBarController for what you are trying to do; it would seem more natural to me (but you should find a way to reduce you 6 button to 5, otherwise they will not be displayed all at once).
Otherwise, a UINavigationController seems fine to me. For each button you push a new controller to deal with that button functionality, then you pop back. It should work easily.
EDIT:
have you tried with?
[self.view addSubview:instructions.view];
Your first question Yes you should use navigation based controller ... so when you press any button will open the other view controller with animation.. also Navigation Based Controller keep track of the parent controller if you have any created objects will be retained in the parent view controller that is the root of the Navigation.
here is the steps that you should use.
1-Create Navigation controller in the main application delegate and make it's root is the view controller.
2-when you push the view controller that have 6 buttons .
3- you can check this link for get photo album also if you have changed the source type to camera then you can get the image...
Photo Libaray
4- once you get the image you can add it to NSMutableArray that exist on the NavigationViewController root in your case will be the view which have the 6 buttons.
5-sice every time you want to view the array which contain the photos you will initialize the data source of the uitableviewcontroller with the array that you save photos on.
Thanks
I think the problem is coming from one of two places:
As I understand it, these are all different View Controllers, correct? And they have their own xib files? If that is true, then calling:
Instructions *i = [[Instructions alloc]init];
is insufficient. You need to use
Instructions *i = [[Instructions alloc] initWithNibNamed:#"Instructions"];
in order to include that view that you have already constructed in the interface builder.
The other thing I see potentially going wrong is that you are inserting all the views at the same index. Think of the index as a layer in photoshop. If you want the new view to be visible overtop of the last one, then it needs to be a higher index. This is handled automatically if you use addSubview: instead of insertSubview: atIndex:
Let's say I have created a model and a view for an iPad. If I have a second screen and want to replicate that view on that second screen is there a facility to do so automatically in iOS (getting automatic mirroring of first view in second view in REAL TIME) ?
Does this mechanism work for both vga and airplay ?
Seems this question is too hard nobody seems to know ?
To precise the first View must stay on iPad and the second view will be on second view and SYNCHRONIZED with first view (same model). ie When User modifies First View, Second View should show same update.
My views would not contain only images, they can contain anything (fields, webview, buttons etc.)
i have not understood your question completely.
do you want same view in second screen as first view or you want make mirror effect of first view in second view?
if you want the same view as first view in sceond view, then directly get the object as first view and add it as subview in second view.
if you want to create mirror effect then you have write a logic code, i dont know there is any third party library for that,
Please do explain your question
I haven't tried it myself, but ReflectionView does something very similar. You may be able to adapt it to solve your problem.
I'm working on my first app and I've issues on how to layout some of its logics.
Basically, what the app is supposed to do is to show a first screen when launched where user can fill in some values and press a button that opens a tableview which shows results. The first screen (view), outlets and connections are all working fine. The issue I'm having is how to leave this "home" search view and show the results to the end user on a table view. Right now, I've only 1 view with its related View Controler and this controller handles the tasks of taking user inputs and get results throughout a HTTP post request.
I need your guidance...Thx in advance
Stephane
Is there a reason that this all has to happen on one screen? iOS is set up to allow for this to happen very easily and (I think) attractively by using a UINavigationController and pushing in a new view controller (could be a UITableViewController or simply a UIViewController that contains a UITableView).
If you MUST have all of this take place in one view, Swastik is correct that it will require some view acrobatics. One way to do it attractively is to use the UIView animations introduced with iOS 4.
Here's Apple's UIView documentation: UIView Class Reference
Specifically, check out the CLASS methods of:
1. animateWithDuration:animations: (with or without completion:)
2. transitionWithView:duration:options:animations:completion:
Note that these methods will require you to learn a little bit about blocks, but it's worth it and I think blocks give tremendous power!
With the methods mentioned above, you could fade out your form and fade in your tableview, or maybe just move the form off-screen while the table view flies in. The possibilities are limited only by your imagination.
u can add a table in ur xib.Initially make it hidden, & when u need to show it unhide it & also if u want to update table's data , you can reload the data of the table.
I'm diving into iOS development and am getting familiar with navigation view controllers. I'm trying to build a simple app with a table view that allows me to add objects to it. So far, I have a table view with an add "+" button in the nav bar that allows me to load my CreateObjectView and display it modally so the user can define the new object, but when they click the save button, I don't know how to send that object data back to the parent view that created the CreateObjectView that contains the object data.
When I create the child view (CreateObjectView), I could pass into it a pointer to the current view before I push it onto the nav stack, but this just feels dirty and circular.
I was reading about protocols and delegates and I could use that approach as well, but it also feels circular.
This question seems like it would be a common design issue to any tableview-based or nav-based app, how should I probably access the view that is one level up from my current view in a nav-based iOS app?
Thanks so much in advance for all your help!
It feels circular at first, but it is the right way. Before the UINavigationController pushes the new view controller you should set the delegate to the current view controller - assuming that's the object you wish to communicate with. Of course you could set it somewhere else instead, such as to a central Core Data handler. Then when you need to communicate call the delegate with the method you have defined. I've done several navigation apps like this after seeing Apple's cookbook example, and it really works well.