i'm very new to xcode. i've googled this and even serched here and i didn't find exactly what i was looking for. i really wanna get this. especially since it's the most basic thing there is.
so, i have the .h and .m files
i want to DRAG a uiview into the .xib file, i don't want it to be as big as the screen, so i resize it.
now i want to draw a bunch of rectangles INSIDE this view object.
how do i go about doing this?
your help would be greatly appreciated!
So you add a generic UIView then create a subclass of UIView and do your drawing inside the drawRect method.
Then change the class of the UIView to your subclass name in the inspector.
Be sure to #include your header in the app delegate.
That's the basic thing.
For more sophistication, you're going to want to learn to use UIViewController subclasses as well. These are used all over ios.
Related
Across my app I have several different subclasses of UIView: UIDatePicker, UIPicker, UIButton, UITableView, UITableViewCell, UITextView, etc. etc... For each of these I'd like to add a very simple drawRect custom implementation that I have working great.
Is there a simple way to get multiple subclasses of UIView to all have the same drawRect implementation without creating a subclass and repeating the same code across each UIPicker, UIButton, etc. etc... ?
I realize the solution to this is probably to write a delegate class for UIView's layer property and do the custom drawing in drawLayer, but I thought I would ask before I go re-working my code.
The answer seems to be no.
Furthermore, it appears that my idea for the workaround also doesn't work: I was thinking I could write a nice little class that implements the drawLayer method from CALayerDelegate and do the drawing in there, and then in each UIView or UIView subclass' init method do a self.layer.delegate = niceLittleCALayerDelegateClass.
My research, however, happened upon this: https://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CALayer_class/#//apple_ref/occ/instp/CALayer/delegate which contains the damning sentence: In iOS, if the layer is associated with a UIView object, this property must be set to the view that owns the layer.
So, double nope.
Against rmaddy's advice I'm going to just write a subclass for each of the UIView subclasses I want to implement this drawing behavior in. We'll see how that goes.
Update:
I can't believe I didn't think of this before, but the "right" way to do this (that is to say without subclassing UIView's subclasses and adding a custom drawRect method to each subclass's subclass), from everything I can find, seems to be to either create a subview or a sublayer with a transparent background that does whatever custom drawing you want.
Obviously this is going to draw on top of the UIView you're actually using, so this would get exceedingly complicated if you're trying to draw things that interact with the default elements of the UIView, but for my purposes (just a simple frame drawn with a UIBezierPath) it seems to work great.
At present I'm not sure if the subview or the sublayer approach is more efficient. If anyone can shed light on that, I'd appreciate it.
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.
I am trying to implement the OBShapedButton class in my iOS project so I can create irregular shaped buttons defined by png files. This is a link for more information on OBShapedButton.
Basically this class works great when I'm using it with my nib files. However I prefer using storyboard in my projects. But when I try to do the same thing in storyboard, following all the same steps for making an irregular button as I do in my nib files, it doesn't work and the clickable area is still defined by a rectangle and not my png image.
My question is how would I go about using storyboard with OBShapedButton? Is there something I am missing about storyboard that would prevent OBShapedButton from working?
I'm using it in a project with Storyboards. Be sure the set the Custom Class in the Identity inspector to OBShapedButton, I don't think I did anything else special.
I am just starting out with iOS app development and it's been a great experience so far. Apple documentation is great, but there are some questions I have that are not as technical and only someone with experience might be able to answer.
I have a bunch of UIViewController which handle the "dynamic skinning" of the custom UIViews that they control. This leads to a controller with big chunks of code which seems a bit unpractical to me.
So the question is: Following the MVC pattern, should I give the responsibility of setting a UIFont, UIColor, etc to the view itself? Or should I create "micro" controllers that handle this task using some kind of input?
Thanks for the response.
Creating UIView subclasses that handle the layout works. Override layoutSubviews in the UIView subclass to do the positioning layout (setting frames etc). I find the init method to be a good place to set fonts, colors etc.
Now the UIViewController has relatively little code related to the custom UIView. The viewController just needs to position an instance of the custom UIView and perhaps set a few properties (like a textLabel's text).
If I'm creating a UIView programmatically and I wish to change the UIView properties (background, for example, or actually, messing with CALayers), must I place the code outside of UIView such as in the View controller? Can I put the code somewhere inside UIView?
I was checking out the CoreAnimationKioskStyleMenu example, its code is inside UIView but it's loaded from Nib and can be placed at awakeFromNib, so it doesn't seem to apply to my case.
That depends. Obviously, a good way to handle this is to use a xib file, as it is designed to hold data like this, but that isn't always the best answer for every situation.
If the view is meant to be reused frequently (like a button, or some widget) throughout the application, its best to store all that customization in a subclass of the UIView.
If its a single larger view that will always be managed by a UIViewController, you can keep some of the information in the UIViewController. However, if you end up subclassing a UIView anyway it's probably best practice to keep the data in the UIView.
As a general note, I believe its worth your time to push as much of this data into a xib using interface builder. Magic values (like colors or sizes) peppered through your code will always be a problem if you want to modify it. I have found modifying a xib to be much easier.
Actually there are some methods where you could place initialization/ customization code.
(void)willMoveToSuperview:(UIView *)newSuperview;
(void)didMoveToSuperview;
will get called as soon as u add the view as a subview to another view, at which point you already have the frame and all the properties, and you can do further customizing as you wish.
(void)layoutSubviews -- generally used for changing subviews' frames and layout organization.
Will get called each time the view needs to be redrawn by the system, or when you specifically call [self setNeedsLayout] on your UIView.
Hope this helps.