WKWebview 拼接tableview，获取web内容高度

- (void)addWKWebView
{
    _webView = [[WKWebView alloc] initWithFrame:CGRectMake(, , SCREEN_WIDTH, 0.1)];
    [_webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:_activityModel.shareLink]]];
    _webView.scrollView.scrollEnabled = NO;
    _webView.UIDelegate = self;
    _webView.navigationDelegate = self;
    [_tableView setTableHeaderView:_webView];
    [SVProgressHUD show];
}

- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation
{
    [webView evaluateJavaScript:@"document.getElementById(\"content\").offsetHeight"
              completionHandler:^(id _Nullable result,NSError * _Nullable error) {
//        获取页面高度，并重置webview的frame
        _webViewHeight = [result doubleValue];
        CGRect frame = webView.frame;
        frame.size.height = _webViewHeight;
        webView.frame = frame;
        [_tableView beginUpdates];
        [_tableView setTableHeaderView:_webView];
        [_tableView endUpdates];
        [self getActivityComments];
    }];
}

- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation{

}

- (void)addTableView
{
    _tableView = [[UITableView alloc] initWithFrame:CGRectMake(,, SCREEN_WIDTH, SCREEN_HEIGHT-- ) style:UITableViewStylePlain];

    [_tableView setBackgroundColor:[UIColor clearColor]];
    [_tableView setDelegate:self];
    [_tableView setDataSource:self];
    _tableView.tableFooterView = [UIView new];
    _tableView.separatorStyle = UITableViewCellSeparatorStyleSingleLine;
    _tableView.separatorColor = SEPARATOR_COLOR_SYSTEM;
    [self.view addSubview:_tableView];
    [self loadLoadMoreFooter:_tableView action:@selector(loadMoreData)];

}