我正在尝试通过代码构建View。在我的初始化中，我有这个:-(id)init{self=[superinit];if(self){[selfsetFrame:CGRectMake(0,0,0,50)];[selfaddSubview:[selfdateNumberView]];NSDictionary*views=NSDictionaryOfVariableBindings(self.dateNumberView);[self.dateNumberViewaddConstraints:[NSLayoutConstraintconstraintsWithVisualFormat:@"|-