WKWebView not rendering correctly in iOS 10

Question

I have WKWebView inside the UITableViewCell. The web view load request and then after finished loading, I\'ll resize the web view height to be equal to its content height, t

Answer 1

In objective-C this is how I solve the problem.

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    NSArray * visibleCell = [self.tableView visibleCells];

    for (CustomUITableViewCell * cell in visibleCell) {
        if ([cell isKindOfClass:[CustomUITableViewCell class]]) {
            [cell.wkWebView setNeedsLayout];
        }
    }
}

That code will collect all visible cell and do the setNeedsLayout in fast enumeration during user scroll.

Answer 2

Im also have uitableview with cell with wkWebView. And i stack with same problem. But timely you can fix this with this code. By performance do not worry. I tested this solution on iphone 5s and it was taken 10-15% CPU only when you scrolling uitableView with visible web cell.

func scrollViewDidScroll(_ scrollView: UIScrollView) {
   //TODO: Remove this fix when WKWebView will fixed
   if let cell = tableView.cellForRow(at: IndexPath(row: 1, section: 0)) as? WKWebViewCell {
      // Here we take our cell
      cell.wkWebView?.setNeedsLayout() 
      // here is "magic" (where wkWebView it is WKWebView, which was 
      // previously added on cell)
   }
}

Answer 3

You need to force the WKWebView to layout while your UITableView scrolls.

// in the UITableViewDelegate
func scrollViewDidScroll(scrollView: UIScrollView) {
    if let tableView = scrollView as? UITableView {
        for cell in tableView.visibleCells {
            guard let cell = cell as? MyCustomCellClass else { continue }
            cell.webView?.setNeedsLayout()
        }
    }
}

Answer 4

    func reloadWKWebViewIfNeeded() {
    for cell in self.tableView.visibleCells {
        guard let webviewCell = cell as? WebviewCell else { continue }

        // guard cell height > screen height

        webviewCell.webview.reload()
    }
}

override func scrollViewDidEndDragging(scrollView: UIScrollView, willDecelerate decelerate: Bool) {
    guard !decelerate else { return }

    self.reloadWKWebViewIfNeeded()
}

override func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
    self.reloadWKWebViewIfNeeded()
}

Not the best solution though, but at least user can see the rest of the content

Answer 5

I have the same problem - add a WKWebView to a UITableViewCell, and I solved this problem by these steps:

1.Create a UITextView instance and add it to UITableView's superview(UIViewControllew.view) 2.implement codes in scrollViewDidScroll like this:

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    [self.xxtextView becomeFirstResponder];
    [self.xxtextView resignFirstResponder];
}

These codes may cause increased cpu performance overhead, you can fix it by some way such us use a temp variable as threshold value.

I don't think this is a perfect solve method, but it works for me.

---

Eventually I realized that textview becomeFirstResponder just led the webview layout again, so you can just fix it like this:

CGFloat tempOffset = 0;

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    if (!tempOffset || ABS(scrollView.contentOffset.y - tempOffset) > ScreenHeight/2)
    {
        [self.wkWebView setNeedsLayout];
        tempOffset = scrollView.contentOffset.y;
    }
}