Question

有两个视图headerView和footterView。我希望将视图放在另一个下面。我的意思是说headerView在topView和footerView下面headerView。

UIView *mainview = [[UIView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height)];
    headerView =  [[[NSBundle mainBundle] loadNibNamed:@"BaseHeader" owner:self options:nil] objectAtIndex:0];
    footterView = [[[NSBundle mainBundle] loadNibNamed:@"BaseFotter" owner:self options:nil] objectAtIndex:0];

 self.view = mainview;
 [mainview  addSubview:headerView];
 [mainview  addSubview:footterView];

我尝试过添加约束

NSDictionary *viewsDictionary =
NSDictionaryOfVariableBindings(headerView,footterView);

NSLayoutConstraint *constraint = [[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[headerView]-[footterView]|" options:0 metrics:nil views:viewsDictionary] objectAtIndex:0];

NSLayoutConstraint *mconstraint = [[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[headerView(==footterView)]|" options:0 metrics:nil views:viewsDictionary] objectAtIndex:0];

[mainview addConstraint:constraint];
[mainview addConstraint:mconstraint];

但是屏幕上始终只显示footerView。如果我按以下顺序添加View，则始终显示HeaderView。

[mainview  addSubview:footterView];
[mainview  addSubview:headerView];

在xib（BaseHeader.xib和BaseFotter.xib）中都检查了AutoLayout。我需要在xib中做更多吗？

Answer 1

更改约束，将代码添加到：

NSArray * constraints = [NSLayoutConstraint constraintsWithVisualFormat：@“V：| [headerView] - [footterView] |” options：0 metrics：nil views：viewsDictionary];

NSArray * mconstraints = [NSLayoutConstraint constraintsWithVisualFormat：@“V：| [headerView（== footterView）] |” options：0 metrics：nil views：viewsDictionary];

[mainview addConstraints：constraints]; [mainview addConstraints：mconstraints];

以编程方式生成的视图的AutoLayout

1 个答案: