Question

When this Action is executed it displays totally black view screen with toolbar

- (void)displayviewsAction:(id)sender
{

self.view = [[[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]]autorelease];

self.view.frame = CGRectMake(0, 0, 320, 480);

[self.view addSubview:toolbar];

UIView *viewController = [[UIView alloc] init];

UIView *secondController = [[UIView alloc] init];

[self.view insertSubview:viewController atIndex:1];

[self.view insertSubview:secondController atIndex:2];

NSLog(@"%d", [[self.view subviews] indexOfObject:viewController]); // Is 1

NSLog(@"%d", [[self.view subviews] indexOfObject:secondController]); // Is 2

[self.view bringSubviewToFront:viewController];

 NSLog(@"%d", [[self.view subviews] indexOfObject:viewController]);

[self.view sendSubviewToBack:viewController];

 NSLog(@"%d", [[self.view subviews] indexOfObject:viewController]);

[self.view bringSubviewToFront:secondController];

NSLog(@"%d", [[self.view subviews] indexOfObject:secondController]); 

SecondViewController * secondController = [[[SecondViewController alloc] init]autorelease];

secondController.view.frame = CGRectMake(0, 0, 320, 480);

[self.view addSubview:secondController.view];

[self.view addSubview:toolbar];

}

Any ideas why the view is appearing as totally black with toolbar.

Answer 1

The default background color of views is nil, which is a transparent background.

If you have nothing in any of the views and set no background color for any of them, the default background of the window or the device will show through. I didn’t see it in the documentation, but I am assuming it is black.

Also, you have defined UIView pointers, but named them with the word “controller”. This can contribute to mistakes since a UIViewController is an entirely different object. The UIViewController contains a UIView and interacts with it, but it is not a UIView, nor does it inherit from one.