自定义子视图不适合父视图答案

【问题标题】：Custom child view does not fit parent自定义子视图不适合父视图
【发布时间】：2020-11-16 22:09:56
【问题描述】：

我在 XIB 中有一个与 viewController 链接的视图设置，XIB 中的所有视图都具有预期的布局。但是，某些视图必须在代码中初始化，因此我将它们添加为子视图，这样：

//Setup first custom view
FirstCustomView *firstCustomView = [[FirstCustomView alloc] initWithFrame: self.firstView.frame withDelegate:self];
 //where self.firstView is a UIView
[self.firstView addSubview: firstCustomView];

//Setup second custom view
SecondCustomView *secondCustomView = [[[NSBundle mainBundle] loadNibNamed:@"SecondCustomView" owner:nil options:nil] firstObject];
 //where self.secondView is a UIView
[self.secondView addSubview: secondCustomView];

正如您所见，有些视图是从 XIB 初始化的，有些是用框架初始化的。无论哪种方式，我都遇到了同样的问题，即子视图没有填充父视图。有什么建议吗？

【问题讨论】：

标签： ios objective-c autolayout xib autoresize

【解决方案1】：

我用于这类东西的一些代码...

// Given a parent view, embed a child view in it so that the child spans the full parent
+ ( void ) embed:( UIView * ) child
        into:( UIView * ) parent
{
    [parent addSubview:child];
    
    [child.topAnchor    constraintEqualToAnchor:parent.topAnchor].active    = YES;
    [child.rightAnchor  constraintEqualToAnchor:parent.rightAnchor].active  = YES;
    [child.leftAnchor   constraintEqualToAnchor:parent.leftAnchor].active   = YES;
    [child.bottomAnchor constraintEqualToAnchor:parent.bottomAnchor].active = YES;
}

【讨论】：