UIView is never rendered if added as subview in viewDidLoad - ios

Question

I'm trying to add a subview to a view controller programatically, but it seems like if I add the subview in the viewDidLoad of the view controller whatever I have added as subview in the view itself is not rendered in the view controller.
But if I move the [self.view addSubview:myUIView] in the init method of the view controller, everything is rendered.
Also, if I call the same methods in the viewDidAppear I get all the elements rendered, but it's right after the view controller was displayed, and I can see when the elements are rendered in the view controller.
This would be my view controller:
//interface
#class RLJSignInView;
#protocol RLJSignInViewControllerDelegate;
#interface RLJSignInViewController : UIViewController <UITextFieldDelegate>
#property (nonatomic, readwrite) RLJSignInView *signInView;
#property (nonatomic, assign) id<RLJSignInViewControllerDelegate> delegate;
#end
//implementation
#import "RLJSignInViewController.h"
#import "RLJSignInView.h"
#import "RLJSignInViewControllerDelegate.h"
#import "UIColor+RLJUIColorAdditions.h"
#implementation RLJSignInViewController
- (id)init
{
self = [super init];
if (self) {
_signInView = [[RLJSignInView alloc] initWithFrame:self.view.bounds];
[self.view addSubview:self.signInView];
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
NSLog(#"%#", self.signInView);
[self.view setBackgroundColor:[UIColor rgbWithRed:250 green:250 blue:250]];
}
#end
And this would be my view:
//interface
#interface RLJSignInView : UIView
#property (strong, nonatomic, readwrite) UITextField *username;
#property (strong, nonatomic, readwrite) UITextField *password;
#property (strong, nonatomic, readwrite) UIButton *signIn;
#property (strong, nonatomic, readwrite) UIButton *signUp;
#end
//implementation
#import "RLJSignInView.h"
#import "UITextField+RLJUITextFieldAdditions.h"
#import "UIButton+RLJUIButtonAdditions.h"
#implementation RLJSignInView
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
CGRect usernameInputFrame = CGRectMake(10.0, 40.0, self.bounds.size.width - 20, 40);
CGRect passwordInputFrame = CGRectMake(10.0, 79.0, self.bounds.size.width - 20, 40);
CGRect signInButtonFrame = CGRectMake(10.0, 160, self.bounds.size.width - 20, 40);
CGRect signUpButtonFrame = CGRectMake(10.0, 220, self.bounds.size.width - 20, 40);
UIView *usernameInputLeftView = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, 10.0, 40)];
UIView *passwordInputLeftView = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, 10.0, 40)];
self.username = [[UITextField alloc] initWithFrame:usernameInputFrame
textAlignment:NSTextAlignmentLeft
textColor:[UIColor blackColor]
clearButton:UITextFieldViewModeWhileEditing
leftView:usernameInputLeftView
placeholder:#"Username"
backgroundColor:[UIColor whiteColor]
strokeWidth:2.0
strokeColor:[UIColor lightGrayColor]
keyboardType:UIKeyboardTypeEmailAddress
byRoundingCorners:UIRectCornerTopLeft | UIRectCornerTopRight
cornerRadii:CGSizeMake(4.0, 4.0)
secure:NO];
self.password = [[UITextField alloc] initWithFrame:passwordInputFrame
textAlignment:NSTextAlignmentLeft
textColor:[UIColor blackColor]
clearButton:UITextFieldViewModeWhileEditing
leftView:passwordInputLeftView
placeholder:#"Password"
backgroundColor:[UIColor whiteColor]
strokeWidth:2.0
strokeColor:[UIColor lightGrayColor]
keyboardType:UIKeyboardTypeDefault
byRoundingCorners:UIRectCornerBottomLeft | UIRectCornerBottomRight
cornerRadii:CGSizeMake(4.0, 4.0)
secure:YES];
self.signIn = [[UIButton alloc] initWithFrame:signInButtonFrame
title:#"Sign In"
colorNormal:[UIColor whiteColor]
colorHighlighted:[UIColor whiteColor]
colorDisabled:[UIColor whiteColor]
backgroundNormal:[UIColor colorWithRed:82 / 255.0 green:156 / 255.0 blue:201 / 255.0 alpha:1.0]
cornerRadius:4.0];
self.signUp = [[UIButton alloc] initWithFrame:signUpButtonFrame
title:#"Sign Up"
colorNormal:[UIColor blackColor]
colorHighlighted:[UIColor blackColor]
colorDisabled:[UIColor blackColor]
backgroundNormal:[UIColor whiteColor]
cornerRadius:4.0];
[self addSubview:self.username];
[self addSubview:self.password];
[self addSubview:self.signIn];
[self addSubview:self.signUp];
}
return self;
}
#end
I'm not sure what I could do about it, but I know for sure that I would not like the view to be added to the subview on initialisation.
Or maybe I'm doing the rendering of the subviews of the view wrong. I would appreciate some input on this matter if anyone encountered the same thing or if noticed that I messed up something.

Answer 1

Don't call self.view from inside your init method. This will trigger viewDidLoad being called before your init method even returns, which is incorrect behavior.
Instead, follow this pattern:
create your objects (properties / instance variables) in init, or by using lazy instantiation
add the subviews in viewDidLoad
set the frames in viewWillLayoutSubviews
This pattern will avoid bugs like the one you posted here, and set you up for success handling rotation and resizing events in the future.

Answer 2

The key might be you are using self.view.bounds too early. It might work when you provide an initial size frame (like IB would do).
init is too early. The view controller is initializing, the view is not loaded yet, which means there's no view and the bounds will return CGRectZero.
viewDidLoad is also too early to rely on the view's bounds. The view is just loaded, it does not have a superview yet and might be resized later.
viewWillAppear is the first moment you can rely on the view's bounds. Since it will be resized according to the autoresizingmasks or autolayout constraints.
You can add the subview in viewDidLoad but you you should provide an initial frame (and you set the correct autoresizingmasks or constraints) it should all work fine.