Clean programmatically implementation of UI - objective-c

Question

I am trying to make a clean implementation of programmatically created UI.
I start off with my AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.backgroundColor = [UIColor whiteColor];
MainViewController *mainVC = [[MainViewController alloc] init];
UINavigationController *navC = [[UINavigationController alloc] initWithRootViewController:mainVC];
self.window.rootViewController = navC;
[self.window makeKeyAndVisible];
return YES;
}
Then the MainViewController.m is a subclass of UIViewController implements the following:
- (void)loadView {
CGRect applicationFrame = [[UIScreen mainScreen] applicationFrame];
MenuView *contentView = [[MenuView alloc] initWithFrame:applicationFrame];
self.view = contentView;
}
And the custom UIView in MenuView.m implements the following
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
NSLog(#"init got called");
NSLog(#"frame size %f %f", self.frame.size.width, self.frame.size.height);
self.backgroundColor = [UIColor greenColor];
}
return self;
}
...
- (void)loadView {
NSLog(#"loadView got called");
UIButton *newButton = [[UIButton alloc] init];
newButton.titleLabel.text = #"New Button";
newButton.backgroundColor = [UIColor blueColor];
[self addSubview:newButton];
NSDictionary *views = NSDictionaryOfVariableBindings(newButton);
[newButton setTranslatesAutoresizingMaskIntoConstraints:NO];
NSDictionary *metrics = #{#"buttonWidth": #(150), #"buttonHeight": #(150)};
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-(100)-[newButton(buttonWidth)]"
options:0 metrics:metrics views:views]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:[newButton(buttonHeight)]-(100)-|"
options:0 metrics:metrics views:views]];
}
When I run this, the simulator shows me a green screen - but there is no button. The NSLogs in the init method fire and show a frame size of 320 x 548, but the loadView method does not get called.
What am I doing wrong?
Thanks

Answer 1

- (void)loadView;
is a method of UIViewController class, not UIView's.
So you need to setup its subviews inside init method where you already set background color.
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
// Initialization code
}
return self;
}