那些遇到过的问题

今天使用UICollection的扩展与单视图应用程序相比具有不同的行为

ron*_*ory 5 ios uicollectionview swift today-extension swift3

我尝试将一个集合视图添加到今日扩展,并指定每行3个项目的项目,并设置截面插入为20,顶部,左侧,底部和右侧.当我在单视图应用程序中执行此操作时,一切都像预期的那样,但是当我以编程方式为Today Extension执行相同操作时,集合视图看起来不同,尤其是右侧和底部的空间似乎与单视图应用程序中的不同.这有什么区别的原因是什么？我期望今天扩展的行为与单视图应用程序中的行为相同.

为了更好地理解我的问题,下面是单视图应用程序和今日扩展的代码,两者都带有屏幕截图:

单视图应用程序的ViewController:

import UIKit

class ViewController: UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {

    var collectionView: UICollectionView!
    let sectionInsets = UIEdgeInsets(top: 20, left: 20, bottom: 20, right: 20)
    let itemsPerRow: CGFloat = 3

    override func viewDidLoad() {
        super.viewDidLoad()

        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
        layout.sectionInset = sectionInsets

        collectionView = UICollectionView(frame: view.frame, collectionViewLayout: layout)
        collectionView.dataSource = self
        collectionView.delegate = self
        collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cellId")
        collectionView.backgroundColor = .white
        view.addSubview(collectionView)
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 6
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellId", for: indexPath)
        cell.backgroundColor = .blue

        return cell
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let paddingSpace = sectionInsets.left * (itemsPerRow + 1)
        let availableWidth = view.frame.width - paddingSpace
        let widthPerItem = availableWidth / itemsPerRow

        return CGSize(width: widthPerItem, height: widthPerItem)
    }
}
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单视图应用程序的屏幕截图:

在此输入图像描述

Today Extension的TodayViewController:

import UIKit
import NotificationCenter

class TodayViewController: UIViewController, NCWidgetProviding, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {

    var collectionView: UICollectionView!
    let sectionInsets = UIEdgeInsets(top: 20, left: 20, bottom: 20, right: 20)
    let itemsPerRow: CGFloat = 3

    override func viewDidLoad() {
        super.viewDidLoad()

        extensionContext?.widgetLargestAvailableDisplayMode = .expanded

        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
        layout.sectionInset = sectionInsets

        collectionView = UICollectionView(frame: view.frame, collectionViewLayout: layout)
        collectionView.dataSource = self
        collectionView.delegate = self
        collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cellId")
        collectionView.backgroundColor = .white
        view.addSubview(collectionView)
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 6
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellId", for: indexPath)
        cell.backgroundColor = .blue

        return cell
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let paddingSpace = sectionInsets.left * (itemsPerRow + 1)
        let availableWidth = view.frame.width - paddingSpace
        let widthPerItem = availableWidth / itemsPerRow

        return CGSize(width: widthPerItem, height: widthPerItem)
    }

    func widgetActiveDisplayModeDidChange(_ activeDisplayMode: NCWidgetDisplayMode, withMaximumSize maxSize: CGSize) {
        // toggle height in case of more/less button event
        if activeDisplayMode == .compact {
            self.preferredContentSize = CGSize(width: 0, height: 110)
        } else {
            self.preferredContentSize = CGSize(width: 0, height: 220)
        }
    }
}
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Today Extension的屏幕截图:

在此输入图像描述

ron*_*ory 5

在这个答案的帮助下,我解决了自己的问题.到目前为止的解决方案是我只是设置集合视图viewDidAppear(_:)而不是viewDidLoad()今天扩展的TodayViewController(底部的空间当前看起来像那样,因为我设置了220的修复高度):

import UIKit
import NotificationCenter

class TodayViewController: UIViewController, NCWidgetProviding, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {

    var collectionView: UICollectionView!
    let sectionInsets = UIEdgeInsets(top: 20, left: 20, bottom: 20, right: 20)
    let itemsPerRow: CGFloat = 3

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        extensionContext?.widgetLargestAvailableDisplayMode = .expanded

        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
        layout.sectionInset = sectionInsets

        collectionView = UICollectionView(frame: view.frame, collectionViewLayout: layout)
        collectionView.dataSource = self
        collectionView.delegate = self
        collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cellId")
        collectionView.backgroundColor = .white
        view.addSubview(collectionView)
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 6
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellId", for: indexPath)
        cell.backgroundColor = .blue

        return cell
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let paddingSpace = sectionInsets.left * (itemsPerRow + 1)
        let availableWidth = view.frame.width - paddingSpace
        let widthPerItem = availableWidth / itemsPerRow

        return CGSize(width: widthPerItem, height: widthPerItem)
    }

    func widgetActiveDisplayModeDidChange(_ activeDisplayMode: NCWidgetDisplayMode, withMaximumSize maxSize: CGSize) {
        // toggle height in case of more/less button event
        if activeDisplayMode == .compact {
            self.preferredContentSize = CGSize(width: 0, height: 110)
        } else {
            self.preferredContentSize = CGSize(width: 0, height: 220)
        }
    }
}
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现在我得到与单视图应用程序中相同的结果:

在此输入图像描述

更新:

不幸的是,上面的解决方案仍然没有预期的行为.当Today Extension在构建之前处于展开状态时,它看起来像上面的截图,就像预期的那样.问题是当它在构建之前处于折叠状态并且我想扩展扩展时,结果看起来像这样(集合视图的扩展部分被切断):

在此输入图像描述

到目前为止,解决此问题的方法是将集合视图的初始帧.zero设置为并设置框架,viewWillLayoutSubviews()如下所示:

import UIKit
import NotificationCenter

class TodayViewController: UIViewController, NCWidgetProviding, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {

    var collectionView: UICollectionView!
    let sectionInsets = UIEdgeInsets(top: 20, left: 20, bottom: 20, right: 20)
    let itemsPerRow: CGFloat = 3

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        extensionContext?.widgetLargestAvailableDisplayMode = .expanded

        let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
        layout.sectionInset = sectionInsets

        collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
        collectionView.dataSource = self
        collectionView.delegate = self
        collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cellId")
        collectionView.backgroundColor = .white
        view.addSubview(collectionView)
    }

    override func viewWillLayoutSubviews() {
        let frame = view.frame
        collectionView?.frame = CGRect(x: frame.origin.x, y: frame.origin.y, width: frame.size.width, height: frame.size.height)
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 6
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellId", for: indexPath)
        cell.backgroundColor = .blue

        return cell
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let paddingSpace = sectionInsets.left * (itemsPerRow + 1)
        let availableWidth = view.frame.width - paddingSpace
        let widthPerItem = availableWidth / itemsPerRow

        return CGSize(width: widthPerItem, height: widthPerItem)
    }

    func widgetActiveDisplayModeDidChange(_ activeDisplayMode: NCWidgetDisplayMode, withMaximumSize maxSize: CGSize) {
        // toggle height in case of more/less button event
        if activeDisplayMode == .compact {
            self.preferredContentSize = CGSize(width: 0, height: 110)
        } else {
            self.preferredContentSize = CGSize(width: 0, height: 220)
        }
    }
}
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现在行为就像预期的那样,就像在第一个结果屏幕截图中所示,即使今日扩展程序首次崩溃也是如此.

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