iPhone控件之UIView

- (void)viewDidLoad {
    
    [super viewDidLoad];
    
    CGPoint frameCenter = self.view.center;
    float width = 50.0;
    float height = 50.0;
    
    CGRect viewFrame = CGRectMake(frameCenter.x-width,frameCenter.y-height, width*2, height*2);
    UIView *myView = [[UIView alloc] initWithFrame:viewFrame];
    myView.backgroundColor = [UIColor blueColor];
    
    //create subview
    CGRect subViewFrame = CGRectInset(myView.bounds, width/2.0, height/2.0);
    UIView *mySubview = [[UIView alloc] initWithFrame:subViewFrame];
    mySubview.backgroundColor = [UIColor yellowColor];
    
    //set autoresizing mask
    mySubview.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    
    [myView addSubview:mySubview];
                      
    [[self view] addSubview:myView];
    
    //animate resize
    [UIView beginAnimations:nil context:NULL];
    
    [UIView setAnimationDuration:1.0];
    viewFrame = CGRectInset(viewFrame, -width, -height);
    [myView setFrame:viewFrame];
    
    [UIView commitAnimations];
    
    [mySubview release];
    [myView release];    
}