OK, so this one is probably a bit challenging, as it is monotouch...
I have a reusable custom toolbar that that I plan to reuse on multiple screens.
I want to create the toolbar in Interface Builder
I want to be able to update labels on the toolbar from ANY view controller. So I might have five different view controllers that all have this toolbar, and can update labels on it.
So my question is:
How do I even begin to subclass UIView in MonoTouch? If I create a new "iPhone View", all it gives me is a nib. I have no place to hook up outlets or actions.
Given that you are able to tell me how to set up MonoTouch to have C# code files for subclassing UIView so I can handle events and access properties, how do I hook it up to the nib? I see a lot of people saying to use initWithFrame to call loadNibNamed in Objective-C, but this doesn't correctly translate to MonoTouch. How would I do that in MonoTouch?
Given that #1 and #2 are fulfilled, how do I load this custom toolbar into any viewcontroller, and add it at specific coordinates on the screen? Doing the initWithFrame CGRect stuff doesn't seem to have a simple path in MonoTouch
If anyone is able to figure this out, you are amazing!!!!
Thanks you in advance!
So after a lot of digging, I finally found the answer.
The most informative tutorial was here:
http://sgmunn.com/blog/2012/03/using-loadnib-to-load-a-view/
Essentially, you need to create custom subviews, set them up in the interface builder, then do some simple mapping on the MonoTouch side. But the key point that was throwing me off from the example was this:
You must, when subclassing UIView, implement the base constructor for IntPtr
When you do that, everything falls into place. You have your Outlets and Actions hooked up, and can manipulate them at will.
EDIT: To be more descriptive than just linking...
How do I even begin to subclass UIView in MonoTouch? If I create a new
"iPhone View", all it gives me is a nib. I have no place to hook up
outlets or actions.
Create a new iPhone view, it'll create a nib. Open the nib, set the "custom class" to your custom class. MonoTouch should generate it automatically. If it doesn't, create a new C# class and subclass UIView, but make sure you create the constructor for IntPtr. If you use Storyboards, when you call Storyboard.InstantiateViewController() it'll fill in the IntPtr value for you. Note that if you DO use Storyboard.InstantiateViewController, you need to set the identifier as well to your custom class' name.
Once you create that iPhone view, you should be able to open up "code view" in IB and hook up your outlets and actions.
Given that you are able to tell me how to set up MonoTouch to have C#
code files for subclassing UIView so I can handle events and access
properties, how do I hook it up to the nib? I see a lot of people
saying to use initWithFrame to call loadNibNamed in Objective-C, but
this doesn't correctly translate to MonoTouch. How would I do that in
MonoTouch?
There is no initWithFrame: or CGRect in MonoTouch, you use RectangleF. If you load the nib programmatically, you can use the constructor that takes in a RectangleF and use that to set x, y, width, height.
Given that #1 and #2 are fulfilled, how do I load this custom toolbar
into any viewcontroller, and add it at specific coordinates on the
screen? Doing the initWithFrame CGRect stuff doesn't seem to have a
simple path in MonoTouch
For Storyboards use Storyboard.InstantiateViewController (make sure you set the identifier in IB). For everything else, use:
var nibObjects = NSBundle.MainBundle.LoadNib("YourViewName", theController, null);
var instantiatedView = (YourClassName)Runtime.GetNSObject(nibObjects.ValueAt(0));
as depicted in the above link.
Enjoy! - Allison.
Instead of loading Nib files from iOS 9 onwards you can use container views and storyboard reference to achieve the same.
You can check here
Related
I have created a custom view (Quantity View) with nib file in Swift. I have created some IBOutlets & IBActions (for buttons, labels etc.) in my custom view.
I tried to use this custom view (Quantity View) by assigning class name to a UIView in my storyboard.
It's showing me all the IBOutlets & IBActions in the Connections Inspector, as shown in this screenshot: .
I just want to show only delegate for the Custom view.
Possible Answer:
I thought I can use the -viewWithTag to get the views instead of Outlets.
But, I want to know if it's possible with having Outlets also or if there is much better way to do this?
What are the other possible ways (optimum) to handle this situation?
You can also consider the following solution:
You can take the subviews of your QuantityViews(custom view) and you can identify the specific views by its frame origin.
Note : you should know the customview subviews frame
Its not possible to hide IBOutlets from storyboard if you declare the class members as IBs (IBOutlets or IBActions).
The IBOutlets or the IBActions are just indicators to the interface builder so that it can show the names on it when you try to bind them it actually calls the setValue: forKey: method to set the view's reference to the IBOutlet property.
Now if you try to access an subview from the file's owner class without any IBoutlets you need to have a pointer to point it, so for that either you can get the reference using ObjectID which is assigned to the subview by the interface builder or you can get it using the viewWithTag: method.
The ObjectID you need to find all time when you add or replace a subview from the view, so better and convenient approach is to use tag property of UIView class.
So my conclusion to this problem is to access the views using the viewWithTag method you mentioned earlier.
I think your way is correct. But sometimes Xcode doesn't work correctly.
The following makes the IBOutlets and IBActions reappear and work properly:
Clean project your project in Xcode.
Quit Xcode completely.
Delete all contents of ~/Library/Developer/Xcode/DerivedData/.
Restart MacOS just in case.
I hope you will resolve that :)
Since I've seen many other IOS projects written in obj-C, I found that many of them do not use interface builder or storyboard file. It's hard to see what's going on. And I've known that loadview method should do the things similarly to drag and drop objects in IB. So what is the difference between loadview method and doing some dragging objects in interface builder?
Well, you don't have AutoLayout (unless you use hard code to constraints too) and Size Classes without interface builder.
Working with IB is much less coding and more clarity.
If you add a Label to IB then the IB is responsible to release that object. And it's added to the view of course so you don't have to.
I would never go without IB now and would recommend to do so for other devs.
I use Size Classes + AutoLayout and all my screens looks good on every device plus that iOS9 is coming out: I have multiple screens auto enabled because I used Size Classes. App works without maintenance for many years..
Simple difference between IB and loadView
IB:
All u can do is drag and drop things without having any code written.
loadView:
It is first viewCycle method which calls on loading any view of corresponding viewcotroller, You should do all your stuff programmatically here. like adding subviews to your view. and adding constraints etc.
Thanks
I want to design and generate view elements in code, without using storyboard. But I haven't figure out a simple way to locate where should I put my view elements by describing its CGRect. For example, I can drag a button direct into the storyboard and put it where i want, however, in code, I have to write something like
[button setFrame:CGRectMake(24.0f, 113.0f, 271.0f, 140.0f)];
Is there any way or any software can help me?
Your question is a bit broad. You can create your view in code by including in your subclass of UIViewController properties for each subview (control) element and then make all the initialisation in designated initialiser and setting frames and other customisation in viewDidLoad method most likely. But for details where to what set you should go to references for UIViewController lifecycle as it may depend on what you want to achieve. in some cases setting frames in viewDidLoad will be fine whereas sometimes you will need to make some changes in viewDidLayoutSubviews for example.
A quick question from a wanna-be iOS developer. I want to create a UI for an iPhone app without Interface Builder, only programmatically. However, I want to stick to MVC recommendations and separate V and C and have a clean readable code, therefore:
I create UIView class files (e.x. SplashView.h and SplashView.m)
I create UIViewController class files (SplashViewController.h and SplashViewController.m)
I define my UI elements (view, subviews, buttons and text fields) in the UIView class files
I load the main view in view controller's loadView method, and then do other things in view controller's viewDidLoad method
Is this a correct approach to begin with?
Second part of the question, independent of Y/N answer to the first. Where do I define these custom UI elements?
- Inside the view's initWithFrame: method?
- In separate (property getter? property setter?) methods? I.e. do I have to declare each UI element as a property first in the .h file?
If these questions sound a bit ignorant, it must be because they are :) I found lots of sample code on StackOverflow, but little to indicate where you actually put it. I would be really grateful for any help, especially if you could paste/reference some relevant code.
Your list is correct. This is how I do all of my apps. No Interface Builder, just code.
Each custom view typically creates its own subviews in an appropriate initXXX method. This could be initWithFrame: but you could define others as needed. Subview layout can be done through constraints, autoresizing masks, or by implementing layoutSubview.
Each view controller would instantiate its needed views in the viewDidLoad. View layout can be done with constraints, autoresizing masks, or by implementing viewWillLayoutSubviews.
The use of properties is completely optional. Create public properties for anything to be set/get from an outside class. Optionally create private properties for values internal to the implementation.
Go to the Apple website for Sample Code; download everything that you can for applications that are similar to your goal.
I have a nib file where I have a view that contains a background image, a button and another image that covers the full screen (a shadow) that needs to be moved to the front.
On the view, I'm creating child views, and after creating those and adding them using [self addView] I need to move to the front the shadow image.
I'm currently using the tag attribute to find that view, but I'm thinking there's probably a better way, by means of identifying the subviews I add in Interface Builder by some name.
I tries adding a IBOutlet to connect the subview with its parent, but it didn't work (and made no sense, since the subview is already connected to its parent in some way).
The IBOutlets way should work, and is probably the best way to do it. Make sure you made the proper connection in Interface Builder after you declared them in the .h file.
The iPhone does a lazy loading of view controllers. The nib might not have been loaded in initWithCoder or any init method for that matter as Kendall specified.
viewDidLoad is the preferred place to access anything from the nib if you want to access them before the view is displayed.
Hope that helps.
At what point are you trying to access the subviews? If you try within init of a ViewController, the IBOutlets will be nil. The first method you can get at them is probably viewDidLoad.
The reason it does make sense to do things this way is that IBOutlets are just direct pointers to some component, even if they are already subviews of something else. Just saves a lot of hunting.
Using the Tag is a perfectly valid way to locate specific views, so long as you're using the viewWithTag: method. If you're already using tags, there's no need to change to IBOutlets unless you just don't like calling viewWithTag:.