堆栈视图使用固有内容大小，因此使用布局约束来定义视图的尺寸.

Stack views use intrinsic content size, so use layout constraints to define the dimensions of the views.

有一种简单的方法可以快速添加约束(示例):

There is an easy way to add constraints quickly (example):

[view1.heightAnchor constraintEqualToConstant:100].active = true;

完整代码:

- (void) setup {

    //View 1
    UIView *view1 = [[UIView alloc] init];
    view1.backgroundColor = [UIColor blueColor];
    [view1.heightAnchor constraintEqualToConstant:100].active = true;
    [view1.widthAnchor constraintEqualToConstant:120].active = true;


    //View 2
    UIView *view2 = [[UIView alloc] init];
    view2.backgroundColor = [UIColor greenColor];
    [view2.heightAnchor constraintEqualToConstant:100].active = true;
    [view2.widthAnchor constraintEqualToConstant:70].active = true;

    //View 3
    UIView *view3 = [[UIView alloc] init];
    view3.backgroundColor = [UIColor magentaColor];
    [view3.heightAnchor constraintEqualToConstant:100].active = true;
    [view3.widthAnchor constraintEqualToConstant:180].active = true;

    //Stack View
    UIStackView *stackView = [[UIStackView alloc] init];

    stackView.axis = UILayoutConstraintAxisVertical;
    stackView.distribution = UIStackViewDistributionEqualSpacing;
    stackView.alignment = UIStackViewAlignmentCenter;
    stackView.spacing = 30;


    [stackView addArrangedSubview:view1];
    [stackView addArrangedSubview:view2];
    [stackView addArrangedSubview:view3];

    stackView.translatesAutoresizingMaskIntoConstraints = false;
    [self.view addSubview:stackView];


    //Layout for Stack View
    [stackView.centerXAnchor constraintEqualToAnchor:self.view.centerXAnchor].active = true;
    [stackView.centerYAnchor constraintEqualToAnchor:self.view.centerYAnchor].active = true;
}

注意:这是在 iOS 9 上测试的

Note: This was tested on iOS 9