iOS: How do you make two UIViews auto fill space? - iphone

Question

I am trying to programmatically make two views share width of a parent view. I have tried either using an init for the subviews and an initWithFrame, but in either case, I can't get the stretching to work correctly. In the example below, I am expecting to see a red window spanning half of the width of the screen and a green window filling the other half. What am I missing?
self.view = [[UIView alloc] initWithFrame:self.window.frame];
self.left = [[UIView alloc] init];
self.right = [[UIView alloc] init];
[self.left setAutoresizingMask:(UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleHeight)];
[self.right setAutoresizingMask:(UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleHeight)];
[self.view setBackgroundColor:[UIColor blueColor]];
[self.left setBackgroundColor:[UIColor redColor]];
[self.right setBackgroundColor:[UIColor greenColor]];
[self.left setContentMode:UIViewContentModeScaleToFill];
[self.right setContentMode:UIViewContentModeScaleToFill];
[self.view addSubview:self.left];
[self.view addSubview:self.right];
[self.view setAutoresizesSubviews:YES];
[self.window addSubview:self.view];
Thanks!

Answer 1

You never set the initial frame of the 2 views.
This code is tested and working in a UIViewController
- (void)viewDidLoad
{
[super viewDidLoad];
CGRect fullFrame = self.view.frame;
// position left view
CGRect leftFrame = fullFrame;
leftFrame.size.width = leftFrame.size.width / 2;
self.left = [[UIView alloc] initWithFrame:leftFrame];
// position right view
CGRect rightFrame = leftFrame;
rightFrame.origin.x = rightFrame.size.width;
self.right = [[UIView alloc] initWithFrame:rightFrame];
[self.left setAutoresizingMask:(UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleHeight)];
[self.right setAutoresizingMask:(UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleHeight)];
[self.view setBackgroundColor:[UIColor blueColor]];
[self.left setBackgroundColor:[UIColor redColor]];
[self.right setBackgroundColor:[UIColor greenColor]];
[self.left setContentMode:UIViewContentModeScaleToFill];
[self.right setContentMode:UIViewContentModeScaleToFill];
[self.view addSubview:self.left];
[self.view addSubview:self.right];
[self.view setAutoresizesSubviews:YES];
}

Answer 2

Try to set some initial frames of the subviews which you add to the main view. This should help:
self.left.frame = CGRectMake(0, 0, self.window.frame.size.width/2, self.window.frame.size.height);
self.right.frame = CGRectMake(self.window.frame.size.width/2, 0 , self.window.frame.size.width/2, self.window.frame.size.height);