无论我在分配时给它多大的尺寸，它仅显示固定的尺寸。有可能增加吗？

码：

activityIndicator = [[UIActivityIndicatorView alloc] initWithFrame:
                     CGRectMake(142.00, 212.00, 80.0, 80.0)];
[[self view] addSubview:activityIndicator];
[activityIndicator sizeToFit];
activityIndicator.autoresizingMask = (UIViewAutoresizingFlexibleLeftMargin |
                                      UIViewAutoresizingFlexibleRightMargin |
                                      UIViewAutoresizingFlexibleTopMargin |
                                      UIViewAutoresizingFlexibleBottomMargin);
activityIndicator.hidesWhenStopped = YES;
activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyleWhiteLarge;