ActionSheetStringPicker与UIBarButtonItem结合时头部显示异常，如何解决？

当使用ActionSheetStringPicker并将UIBarButtonItem作为origin参数传入时，会出现头部标题栏布局异常的问题（表现为标题区域排版错乱、控件位置偏移）。相关调用代码如下：

func openFilter(sender: UIBarButtonItem) {
    let arr:NSArray = sortingArray as NSArray
    ActionSheetStringPicker.show(withTitle: "Filter Data", rows: arr as [AnyObject], initialSelection: filterPosition, doneBlock: {
        picker, value, index in
        self.filterPosition = value
        self.selectedPos = -1
        self.filterData()
        self.tableViewMain.setContentOffset(.zero, animated:true)
    }, cancel: { ActionStringCancelBlock in return }, origin: sender)
}

以下是几种可行的解决方案：

• 改用UIBarButtonItem对应的视图作为origin
  直接传入UIBarButtonItem会导致picker的定位计算出错，通过value(forKey: "view")获取按钮对应的原生视图作为origin，能让picker正确计算弹出位置，修复头部布局问题。修改后的代码：

  func openFilter(sender: UIBarButtonItem) {
      let arr:NSArray = sortingArray as NSArray
      // 获取UIBarButtonItem对应的视图
      let originView = sender.value(forKey: "view") as? UIView ?? sender
      ActionSheetStringPicker.show(withTitle: "Filter Data", rows: arr as [AnyObject], initialSelection: filterPosition, doneBlock: {
          picker, value, index in
          self.filterPosition = value
          self.selectedPos = -1
          self.filterData()
          self.tableViewMain.setContentOffset(.zero, animated:true)
      }, cancel: { ActionStringCancelBlock in return }, origin: originView)
  }
  

• 自定义头部视图
  如果第一种方法无效，可以直接自定义picker的头部视图，完全控制布局逻辑，避免依赖库的默认头部计算：

  func openFilter(sender: UIBarButtonItem) {
      let arr:NSArray = sortingArray as NSArray
      let picker = ActionSheetStringPicker(title: "Filter Data", rows: arr as [AnyObject], initialSelection: filterPosition, doneBlock: {
          picker, value, index in
          self.filterPosition = value
          self.selectedPos = -1
          self.filterData()
          self.tableViewMain.setContentOffset(.zero, animated:true)
      }, cancel: { _ in return }, origin: sender)
      
      // 构建自定义头部
      let customHeader = UIView(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: 44))
      customHeader.backgroundColor = .systemBackground
      
      let titleLabel = UILabel(frame: customHeader.bounds)
      titleLabel.text = "Filter Data"
      titleLabel.textAlignment = .center
      titleLabel.font = UIFont.systemFont(ofSize: 16, weight: .medium)
      customHeader.addSubview(titleLabel)
      
      // 替换picker头部
      picker?.setCustomHeader(customHeader)
      picker?.show()
  }
  

• 更新库版本
  旧版本的ActionSheetStringPicker可能存在针对UIBarButtonItem的布局bug，尝试将库更新到最新版本，大概率能直接解决该问题。

内容的提问来源于stack exchange，提问作者Sagar Zala