我可以做的一个方法是设置顶部子视图相对于主视图的前导空格和尾随空格，并且在主视图中水平居中。

One way I can do is to set the leading space and trailing space of the top subview with respect to the main view and also centering horizontally in the main view.

youdao

我可以做的一个方法是设置顶部子视图相对于主视图的前导空格和尾随空格，并且在主视图中水平居中。

One way I can do is to set the leading space and trailing space of the top subview with respect to the main view and also centering horizontally in the main view.

youdao