ios - 使用 tableView 函数 scrollToRow 它崩溃了

Question

当 tableView 滚动时，我更新 dataSource 并调用 tableView 函数 reloadData . tableView 后 DidEndDecelerating我调用函数:

let indexPath = IndexPath(row: row, section: 0)
if row < dataModels.count {
   tableView.scrollToRow(at: indexPath, at: .top, animated: true)
}

有时它会崩溃。崩溃日志如下:

0 CoreFoundation  __exceptionPreprocess

1 libobjc.A.dylib objc_exception_throw

2 CoreFoundation +[_CFXNotificationTokenRegistration keyCallbacks]

3 Foundation -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:]

4 UIKitCore -[UITableViewRowData _assertValidIndexPath:allowEmptySection:]

5 UIKitCore -[UITableViewRowData ensureHeightsFaultedInForScrollToIndexPath:withScrollPosition:boundsHeight:]

6 UIKitCore -[UITableView _contentOffsetForScrollingToRowAtIndexPath:atScrollPosition:usingPresentationValues:]

7 UIKitCore -[UITableView _scrollToRowAtIndexPath:atScrollPosition:animated:usingPresentationValues:]

8 UIKitCore -[UITableView scrollToRowAtIndexPath:atScrollPosition:animated:]

Answer 1

先查indexpath存在与否。来电scrollToRow方法。

extension UITableView {
    func isExist(indexPath: IndexPath) -> Bool {
        if indexPath.section >= self.numberOfSections {
            return false
        }
        if indexPath.row >= self.numberOfRows(inSection: indexPath.section) {
            return false
        }
        return true
    }
}


func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
    if !scrollView.isDecelerating {
        let indexPath = IndexPath(row: row, section: 0)
        if tableView.isExist(indexPath: indexPath) {
          tableView.scrollToRow(at: indexPath, at: .top, animated: true)
        }
    }
}