Question

我一直在玩，当它被选中时试图为我的tableviewcell的内容设置动画，但我遇到了问题。我读过一些你无法在didSelectRowAtIndexPath中运行animatewithduration的地方，或者至少它没有动画，如果你这样做的话。我的代码似乎与下面的代码一样，视图移动但不动画。

我已尝试将逻辑合并到willDisplayCell中以监控选择但无济于事，所以如果有人能够为我找到合适的解决方案，我会很高兴，因为尽管有很多搜索，但答案看似无法获得：

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    let currentCellDescriptor = getCellDescriptorForIndexPath(indexPath)
    let cell = tableView.dequeueReusableCellWithIdentifier(currentCellDescriptor["cellIdentifier"] as! String, forIndexPath: indexPath) as! CustomCell
    let indexOfTappedRow = visibleRowsPerSection[indexPath.section][indexPath.row]
    if cellDescriptors[indexPath.section][indexOfTappedRow]["isExpandable"] as! Bool == true {
        if cellDescriptors[indexPath.section][indexOfTappedRow]["isExpanded"] as! Bool == false {


            // INTERESTING BIT: Animates cell contents to Right
            if currentCellDescriptor["cellIdentifier"] as! String == "CellHeader" {
                UIView.animateWithDuration(0.5, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 12, options: .CurveLinear, animations: {
                    cell.headerTitleLeftConstraint.priority = 999
                    cell.headerTitleRightConstraint.priority = 1
                    cell.layoutIfNeeded()
                    }, completion: nil)
            }

       } else if cellDescriptors[indexPath.section][indexOfTappedRow]["isExpanded"] as! Bool == true {
           // MARK: Animates cell contents back to left
           if currentCellDescriptor["cellIdentifier"] as! String == "CellHeader" {
                UIView.animateWithDuration(0.5, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 12, options: .CurveLinear, animations: {
                    cell.headerTitleLeftConstraint.priority = 1
                    cell.headerTitleRightConstraint.priority = 999
                    cell.layoutIfNeeded()
                     }, completion: nil)
                    }
            }

Answer 1

首先，请勿在此处使用dequeueReusableCellWithIdentifier。它将使用屏幕上不可见的单元格并准备显示它。你想要的是cellForRowAtIndexPath，它返回给定indexPath屏幕上已有的单元格。

然后我明白你想玩2个约束并动画布局变化。为此，动画应仅包含layoutIfNeeded：

cell.headerTitleLeftConstraint.priority = 999
cell.headerTitleRightConstraint.priority = 1
UIView.animateWithDuration(0.5, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 12, options: .CurveLinear, animations: {
                cell.layoutIfNeeded()
                }, completion: nil)

我还建议您将此逻辑从控制器传输到CustomCell类。例如，使用selected属性和setSelected(animated: Bool)可视地处理状态更改。

Answer 2

在Tanguy的帮助下，这就是我们的看法。我仍然有一些动画问题，因为桌子本身实际上并没有动画下面的下一级单元格，但我会改进代码并使其正常工作。认为这现在适合用途，所以值得发布以显示解决方案本身。谢谢！

 override func setSelected(selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)
        // Adjusts constraints everytime switch is tapped
        isLeftAligned = !isLeftAligned
            if userHanded == "Right" {
            UIView.animateWithDuration(0.5, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 12, options: .CurveLinear, animations: {
                self.leftHandedHeaderConstraint.priority = (self.isLeftAligned) ? 1 : 999
                self.rightHandedHeaderConstraint.priority = (self.isLeftAligned) ? 999 : 1
                self.layoutIfNeeded()
            }, completion: nil)

        } else if userHanded == "Left" {
            UIView.animateWithDuration(0.5, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 12, options: .CurveLinear, animations: {
                self.leftHandedHeaderConstraint.priority = (self.isLeftAligned) ? 999 : 1
                self.rightHandedHeaderConstraint.priority = (self.isLeftAligned) ? 1 : 999
                self.layoutIfNeeded()
                }, completion: nil)
        }
}

Answer 3

您不需要使用Package: libc6-dbg Status: install ok installed Priority: optional Section: debug Installed-Size: 35315 Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com> Architecture: i386 Multi-Arch: same Source: glibc Version: 2.30-0ubuntu2 Provides: libc-dbg Depends: libc6 (= 2.30-0ubuntu2) Description: GNU C Library: detached debugging symbols This package contains the detached debugging symbols for the GNU C library. Homepage: https://www.gnu.org/software/libc/libc.html Original-Maintainer: GNU Libc Maintainers <debian-glibc@lists.debian.org>。 UIView.animate(...)默认提供动画更新。更改约束后，可以通过调用以下方法来实现：

UITableView

创建时，不要忘记给自己的height属性设置比tableView.performBatchUpdates(nil, completion: nil)低的优先级。否则，AutoLayout将在更新时打破约束（您可以在调试器中观察到此情况）。不应将约束的优先级设置为.required或类似的东西，而应使用999的静态属性来获得更具可读性的代码。

UILayoutPriority

/// Set this wherever you create your height constraint, e.g. in your custom cell's class. heightConstraint?.priority = .defaultHigh的完整代码如下：

didSelectRowAt

Swift - 选择TableView单元格时的动画（didSelectRowAtIndexPath）

3 个答案: