I have an iOS app with multiple ViewControllers. Each view has numerous IB generated UIButtons, each set to custom. I need to change the color of the background in normal and highlighted states. Further, I need to vary the colors to an RGB value based on user interaction. Thus, I can't use image files.
I found an example of a custom class derived from UIButton that implements the color change and click methods to change the colors as I desired. I created a test button and changed its IB custom class to my new class.
I have an outlet property for my IB created button.
The problem I am having is in the viewcontroller.m file when I attempt to access the custom method in my class, xcode can't see the methods.
Use IBAction as a return type for that method
Declare that particular method in .h file
Related
I would like to be able to interact with the UIControl I have made, and therefore want it in my ViewController.
What I tried
I subclassed UIControl (1).
Then I added a UIView to my View Controller and assigned it the new class (2).
But in Interface Builder I am not able to set my outlets to the buttons contained in the new class (1)?!
1:
2:
UIControl's documentation confirms that it is a subclass of UIView, and I should therefore be able to connect the outlets, right?
What am I missing here? :/
Off-course you can't add IBOutlet because buttons what you added to WeekdayControl are in UIViewController, you can't add Outlet to WeekdayControl, buttons only subviews of WeekdayControl, UIViewController is boss here, and you can add outlet only to UIViewController. (Sorry for my English)
Better create you buttons programatically in WeekdayControl.
Must read first:-
You cannot use the UIControl class directly to instantiate controls.
It instead defines the common interface and behavioral structure for
all its subclasses.
The main role of UIControl is to define an interface and base
implementation for preparing action messages and initially dispatching
them to their targets when certain events occur
So, you are doing wrong, if you really need to make a custom view or custom control then you can directly do it by creating a custom UIView and connecting the outlets directly with the view.
I think you missing the objective of subclassing a UIControl, it doesn't give rights to create outlets as it's a subclass of UIView,just read this lines what it is stated in the docs:-
Subclassing Notes
You may want to extend a UIControl subclass for either of two reasons:
To observe or modify the dispatch of action messages to targets for
particular events
To do this, override sendAction:to:forEvent:, evaluate the passed-in
selector, target object, or UIControlEvents bit mask, and proceed as
required.
To provide custom tracking behavior (for example, to change the
highlight appearance)
To do this, override one or all of the following methods:
beginTrackingWithTouch:withEvent:,
continueTrackingWithTouch:withEvent:, endTrackingWithTouch:withEvent:.
I am tired of setting property values to each UILabel in the IB. Is extending the UILabel the only possible way? or there exists some other way to do it?
You could create an IBOuletCollection for the labels and set the properties programmatically (in viewDidLoad for example) using:
[self.outletCollection setValue:whatever forKey:something];
You can also call makeObjectsPerformSelector on the collection in order to send messages to each label.
Assign all the properties to one UILabel
Copy paste the label as many times you want in storyboard or xib
New labels will also get the same properties, you just require to arrange their positions
Then you can go ahead with IBOutlets and manipulate with those
This applies to all the widgets in storyboard/xib.
Also as #dehlen metioned,
If you are using codebase for UI then, Custom Button Class
Inherit UIButton and create a subclass CustomButton
In its init method, assign all the properties which you require, like font, color etc
And assign frame value at use-time, through initWithFrame method.
Or
Add button in storyboard/xib, but in its class property change class name to CustomButton
Thanks #dehlen, You are right, I forgot to mention code side implementation.
After setting the property of a UILabel make copy of it by
Press and hold alt and drag and drop UILabel to another place it will create new copy of that UILabel with same properties.
Where should I customise my IBOutlets?
Say I have created a button with interface builder, created an IBOutlet for it and I would want to change a property during runtime (ex: background color or localized title).
I would think of adding it to the viewDidLoad method, but outlets aren't yet created.
I remember having nil outlets in viewDidLoad, but I might be wrong.
If I move it viewWillAppear, the code will be executed every time the view controller's view appears.
Is there any better place for my IBOutlet related code, so it's only executed once?
Obviously I can do just about any customization using only the interface builder and making use of the User defined runtime attributes or localized stroryboards, but I don't like that since it's much more tedious to change later.
From the Doc
Its clearly says about the Views loaded into the memory in the -viewDidLoad() delegate itself.
I would think of adding it to the viewDidLoad method, but outlets
aren't yet created.
It is a false statement, Because you only get the viewDidLoad: message after IBOutlets are created. So you can safely do any customization in viewDidLoad:
Let’s say you have a Button you want to customise. You put the button at the place where you want it to be and then open the “Identity Inspector” on the right.
There is a textfield for “Custom Class”:
I usually create a subclass of UIButton / NSButton (depending on iOS or OSX) and edit the behaviour, drawing methods and functionality in this class file. Then just add the name of this class in this textfield. Voila!
I've recently started developing an iOS app, which I've never done before, so it's been going a bit slow, but I'm learning, so that's understandable.
I want to make a custom interface, so I've been making subclasses of the default view classes (like UIButton) so that I can define custom drawing. I've been told this is the best way to define custom interface elements that can be reusable. It definitely seems to be working that way. However, I haven't been able to make elements completely reusable by just using a subclass.
For example, in order to prevent a button's text from changing color when it is clicked, I have to manually go into the interface builder and set the button type to "Custom." After that, code that I enter into the subclass's constructor to change attributes seems to work. But I have to do this for every button I add, and in code the "buttonType" attribute is read only. Is there a way for me to define (just once) certain attributes for every instance of my button subclass that I add to the interface?
My goal is to be able to have a button subclass or template that defines all attribute values that I want my buttons to have, and every instance that I add automatically reflects those properties without me having to change anything. More so, I want to be able to modify that subclass/template and have those changes reflected in every existing instance. I have to imagine that this is possible in iOS. There is simply no way to build sophisticated interfaces without this capability.
Define a custom Button class (inherited from UIButton) in your project and in the init set the properties which you wanted to be set across.
In the interface builder go to the the class inspector and enter the button to be of the previously declared button.
buttonType needs to be set for all the button as this is defined at initialization time and exposed as read only property. If you want absolute reusability for your case, create a view, with an embedded button in code. when you create a button, create using the static method buttonWithType.
Wherever you need, drag and drop a UIView and set the view type to be the custom view.
I have a class MyButton : UIButton which inherits from UIButton. I do a bunch of things in the initWithFrame (the only constructor)of MyButton say like setting the backgroundcolor.
Now I want to use this MyButton in my xib. so that I dont keep setting these properties again and again for all my buttons. I have also set the Custom Class to MyButton in the Identity Inspector for the button in the xib.
Nothing still reflects the properties I set in the xib. This could have been easily done if it was in the code.
My question is,
1) What gets called when you create button thru a xib (like you call initWithFrame when you programmatically create a button) ?
2) How do I get it to see the properties I set in the MyButton ? Is moving out of xib and doing it programatically the only way ?
thanks in advance !
Typically with initWithCoder:
You can use the identity inspector in Interface Builder to set values using the keypath of the attributes. In this example, you can change the CALayer properties of the view:
You can simply set it in your xib file. For that:
Select the button in the xib file.
Click the Identity Inspector button.
Type the name of your custom class(MyButton for your case) in the Class field.
Now your button will be with the Type MyButton class.
EDIT
Check Apple's documentation on Adding a Custom Object. This will give you more idea.