StackView Alignment的问题

Question

我想将3个堆栈与不同的对齐方式对齐

1-Image 0-0两个边缘如下图所示

2-用户信息+文本10-10形成两个边缘

当我将它们堆叠在一起时的问题我只能将它们全部设置为0到所有边距，每个堆栈没有堆栈。

在我的项目中所有内容都停留在图像上我希望用户+文本堆栈中的空间来自两个边距！ 如何解决这个问题，如下图所示？

Answer 1

因为我非常喜欢UIStackView，所以我将您的问题作为实验的理由。您可以将以下内容粘贴到Xcode 7游乐场：

import UIKit
import XCPlayground

let hostView = UIView(frame: CGRect(x: 0, y: 0, width: 320, height: 480))
hostView.backgroundColor = .whiteColor()
XCPlaygroundPage.currentPage.liveView = hostView

let headerLabel = UILabel()
headerLabel.translatesAutoresizingMaskIntoConstraints = false
headerLabel.numberOfLines = 0
headerLabel.text = "This is an info text shown on top of the image. The info text should inform the reader about the topic."

let topStackView = UIStackView(arrangedSubviews: [headerLabel])

let image = UIImage(named: "header.jpg")
let imageView = UIImageView(image: image)
imageView.backgroundColor = .yellowColor()
imageView.contentMode = .ScaleAspectFit

let bottomLabel = UILabel()
bottomLabel.translatesAutoresizingMaskIntoConstraints = false
bottomLabel.numberOfLines = 0
bottomLabel.text = "This is the story text. It is interessting and shows a lot insight to the topic. The reader should be eager to read it and at the end he/she would be able to share with friends and family."

let bottomStackView = UIStackView(arrangedSubviews: [bottomLabel])

let stackView = UIStackView(arrangedSubviews: [topStackView, imageView, bottomStackView])
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.axis = .Vertical
stackView.spacing = 10

hostView.addSubview(stackView)

let views = ["stackView": stackView]
var layoutConstraints: [NSLayoutConstraint] = []
layoutConstraints += NSLayoutConstraint.constraintsWithVisualFormat("|[stackView]|", options: [], metrics: nil, views: views)
layoutConstraints += NSLayoutConstraint.constraintsWithVisualFormat("V:|[stackView]", options: [], metrics: nil, views: views)
layoutConstraints.append(headerLabel.leadingAnchor.constraintEqualToAnchor(topStackView.leadingAnchor, constant: 10))
layoutConstraints.append(headerLabel.trailingAnchor.constraintEqualToAnchor(topStackView.trailingAnchor, constant: 10))

let imageSize = image!.size
let imageHeight = hostView.frame.size.width * imageSize.height / imageSize.width
layoutConstraints.append(imageView.heightAnchor.constraintEqualToConstant(imageHeight))

layoutConstraints.append(bottomLabel.leadingAnchor.constraintEqualToAnchor(bottomStackView.leadingAnchor, constant: 10))
layoutConstraints.append(bottomLabel.trailingAnchor.constraintEqualToAnchor(bottomStackView.trailingAnchor, constant: 10))

NSLayoutConstraint.activateConstraints(layoutConstraints)

或者您可以查看我的UIStackViewPlayground的“故事视图”页面。