TableView无动画重载仍抖动及多选行时取消全选按钮状态同步问题

Let’s work through your two TableView problems step by step:

1. Jitter When Reloading Section Without Animation #

The .none animation flag doesn’t always prevent underlying layout recalculations that cause jitter. Here are the most effective fixes:

• Skip reloading the entire section if you only need to update header/footer content
  Reloading a section forces the TableView to remeasure all rows in that section, even with no animation. Since your section reload is tied to updating the header button (we’ll fix that next), this is likely the main source of your jitter.

• Disable estimated heights
  If you’re using estimatedRowHeight or estimatedSectionHeaderHeight, the TableView may do extra layout guesswork that leads to jumps. Try setting explicit heights or disabling estimates entirely:

  notesTable.estimatedRowHeight = 0
  notesTable.estimatedSectionHeaderHeight = 0
  

• Batch layout updates manually
  Sometimes wrapping changes in beginUpdates()/endUpdates() smooths out unexpected layout shifts. Instead of reloadSections, use:

  DispatchQueue.main.async {
      self.notesTable.beginUpdates()
      self.notesTable.endUpdates()
  }
  

  This triggers a layout pass without reloading content, which can eliminate minor jitter.

2. Fix Deselect All Button State Without Section Reload #

Your current approach uses section reload to update the button’s enabled state, which is causing the jitter. Here’s a smoother, more efficient way:

First, set up a reference to your "Deselect All" button—either via a custom header class or a tag. For a custom header:

class FilterSectionHeader: UITableViewHeaderFooterView {
    let deselectAllButton = UIButton(type: .system)
    
    override init(reuseIdentifier: String?) {
        super.init(reuseIdentifier: reuseIdentifier)
        // Add button setup (title, constraints, etc.) here
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

Then, update your shouldEnableDeselectButton property to directly modify the button instead of reloading the section:

var shouldEnableDeselectButton = false { 
    didSet { 
        guard oldValue != shouldEnableDeselectButton else { return }
        DispatchQueue.main.async {
            // Fetch the header view and update the button
            if let header = self.notesTable.headerView(forSection: self.indexofFilter) as? FilterSectionHeader {
                header.deselectAllButton.isEnabled = self.shouldEnableDeselectButton
            }
        }
    } 
}

If you’re not using a custom header, use a tag to locate the button:

// In your header setup (e.g., tableView(_:viewForHeaderInSection:))
button.tag = 1001

// In the didSet block:
if let header = self.notesTable.headerView(forSection: self.indexofFilter),
   let button = header.viewWithTag(1001) as? UIButton {
    button.isEnabled = self.shouldEnableDeselectButton
}

This way, you only update the button’s state directly—no section reload needed, which eliminates the jitter entirely.

内容的提问来源于stack exchange，提问作者mfaani