Why UITableView works but UIView doesn't

Question

I'd like to pop an view with textInput box and button. I can't understand why UITableView works but UIView doesn't.

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.containerView = [[UITableView alloc] initWithFrame:CGRectMake(20, 100,200,200)];
    [[self view]addSubview:self.containerView];
}

Use above code I can saw the view. But if I change to:

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.containerView = [[UIView alloc] initWithFrame:CGRectMake(20, 100,200,200)];
    [[self view]addSubview:self.containerView];
}

I will get nothing, a black screen. Nothing displayed. Could someone tell me the reason? Thank you very much.

Answer 1

self.containerView = [[UIView alloc] initWithFrame:CGRectMake(20, 100,200,200)];
self.containerView.backgroundColor = [UIColor redColor];

try this code .