iOS10 - 在UITableView标题中阻止UIButton触摸的ContentView [英] iOS10 - ContentView Blocking Touches of UIButton in UITableView Header

问题描述

我正在使用Swift 2.3和Xcode 8 Beta 1将我的应用更新到iOS10，我发现有一个 UITableViewHeaderFooterContentView 这会阻止触摸我的子类 UITableViewHeaderFooterView 上的UIButton。

I am in the process of updating my app to iOS10 with Swift 2.3 and Xcode 8 Beta 1 and I have found that there is a UITableViewHeaderFooterContentView which is blocking touches to the UIButton on my subclass of UITableViewHeaderFooterView.

在Xcode 8 Beta 1模拟器上，UIButton适用于iOS9.3但不适用于iOS10。

On the Xcode 8 Beta 1 simulator the UIButton works on iOS9.3 but not iOS10.

1）有没有这方面的文档？

1) Is there any documentation for this?

2）如何确保我的UI元素位于iOS10的新内容视图之上？ （或允许通过 UITableHeaderFooterContentView 进行触摸）

2) How can I ensure my UI elements are on top of the new Content View in iOS10? (or allow touches through the UITableHeaderFooterContentView)

谢谢！

表格标题

import UIKit

class TableHeader: UITableViewHeaderFooterView {

    @IBOutlet weak var dayLabel: UILabel!

    @IBOutlet weak var dateLabel: UILabel!

    @IBOutlet weak var addNewEventButton: UIButton!

}

代码在视图控制器中
dateCell.addNewEventButton 是在iOS10中不再接收触摸的UIButton

Code In View Controller dateCell.addNewEventButton is the UIButton that is no longer receiving touches in iOS10

func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {


    let tintColor = TintManager().getTintColour()

    let dateCell:TableHeader = tableView.dequeueReusableHeaderFooterViewWithIdentifier("TableHeader") as! TableHeader

    //dateCell.bringSubviewToFront(dateCell.addNewEventButton)

    dateCell.dayLabel.text = Dates.day.uppercaseString

    dateCell.dateLabel.text = Dates.date

        dateCell.backgroundView = UIView(frame: dateCell.frame)
        dateCell.backgroundView!.backgroundColor = tintColor
        dateCell.dayLabel.textColor = UIColor.whiteColor()
        dateCell.dateLabel.textColor = UIColor.whiteColor()
        dateCell.addNewEventButton.backgroundColor = tintColor



    dateCell.addNewEventButton.tag = section
    dateCell.addNewEventButton.layer.cornerRadius = 20.0

    if (savedEventView.superview === self.view) {
        dateCell.addNewEventButton.removeTarget(nil, action: nil, forControlEvents: .AllEvents)
        dateCell.addNewEventButton.addTarget(self, action: #selector(ViewController.userPressedAddButtonToInsertSavedEvent(_:)), forControlEvents:.TouchUpInside)
    } else {
        dateCell.addNewEventButton.removeTarget(nil, action: nil, forControlEvents: .AllEvents)
        dateCell.addNewEventButton.addTarget(self, action: #selector(ViewController.userPressedAddNewEventOnTableViewHeader(_:)), forControlEvents:.TouchUpInside)
    }

    return dateCell
}

推荐答案

违规视图实际上是 UITableViewHeaderFooterView的 contentView （参见 Apple Docs ）。所以你应该只能使用 sendSubview（toBack :) 来阻止它干扰触摸。

The offending view is in fact the contentView of the UITableViewHeaderFooterView (see the Apple Docs). So you should be able just to use sendSubview(toBack:) in order to stop it interfering with touches.

但是，如果视图是从NIB加载的，那么在iOS9下， UITableViewHeaderFooterView 似乎无法正确初始化 contentView 。虽然 contentView 属性不是可选的，但它实际上是nil，如果您尝试访问它，则会出现BAD ACCESS错误。你也不能为 contentView 设置一个值（在代码中或在IB中作为出口），因为它是一个只读属性（*）。因此，我能想到的唯一解决方案是使用 #available 来有条件地包含将contentView移动到后面的代码（如果您在iOS 10或更高版本上运行）。我会将相关代码放入您的子类中：

However, it seems that under iOS9 the UITableViewHeaderFooterView fails to correctly initialise the contentView if the view is loaded from a NIB. Although the contentView property is not optional, it is in fact nil, and you get a BAD ACCESS error if you try to access it. Nor can you set a value for contentView (either in code or as an outlet in IB) because it's a read only property (*). So the only solution I can think of is to use #available to conditionally include code to move the contentView to the back, if you are running on iOS 10 or newer. I would put the relevant code into your subclass:

override func awakeFromNib() {
    if #available(iOS 10, *) {
        self.sendSubview(toBack: contentView)
    }
}

（*）沉迷于狂野的猜测，我的猜测是Apple在 UITableViewCell UITableViewHeaderFooterView 代码>。由于IB在其对象库中有 UITableViewCells （并注意这些包括单元格的 contentView ），它可以确保单元格的contentView被正确实例化。但由于对象库中没有 UITableViewHeaderFooterView ，因此无法正确加载 contentView 。看起来他们通过实例化一个空的 contentView 在iOS10中修复它。可惜他们也没有将 UITableViewHeaderFooterView 添加到库中。

(*) Indulging in wild speculation, my guess is that Apple based the UITableViewHeaderFooterView code heavily on UITableViewCell. Since IB has UITableViewCells in its object library (and notice these include the cell's contentView), it can ensure that the cell's contentView is correctly instantiated. But since there is no UITableViewHeaderFooterView in the object library, there's no way to get the contentView loaded correctly. Looks like they fixed it in iOS10 by instantiating an empty contentView. Pity they didn't also add UITableViewHeaderFooterView to the library.

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