WKWebView计算高度 和 页面大小自适应

下列代码为cell上放了一个WK计算高度返回给viewController刷新tableView

• tableViewCell代码

通过KVO监听webView高度变化
重点:
_wkWebView.scrollView.scrollEnabled = NO; 滚动属性设置为NO不然高度可能不准确
高度返回后记得把监听移除，不然会重复调用

@interface CdConferenceGeneralizeCell () 

@end
@implementation CdConferenceGeneralizeCell

- (instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier{
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self) {
        self.selectionStyle = UITableViewCellSelectionStyleNone;
    }
    return self;
}
- (void)configuration:(CdConferenceDetailModel *)model{
    [self.wkWebView loadHTMLString:model.meetingRemark.introduce baseURL:nil];
}
#define contentSizeKey @"contentSize"

- (WKWebView *)wkWebView{
    if (!_wkWebView) {
        //以下代码适配大小
        NSString *jScript = @"var meta = document.createElement('meta'); meta.setAttribute('name', 'viewport'); meta.setAttribute('content', 'width=device-width'); document.getElementsByTagName('head')[0].appendChild(meta);";
        WKUserScript *wkUScript = [[WKUserScript alloc] initWithSource:jScript injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES];
        WKUserContentController *wkUController = [[WKUserContentController alloc] init];
        [wkUController addUserScript:wkUScript];
        WKWebViewConfiguration *wkWebConfig = [[WKWebViewConfiguration alloc] init];
        wkWebConfig.userContentController = wkUController;
        _wkWebView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 0, HHBWIDTH, 0) configuration:wkWebConfig];
        _wkWebView.scrollView.scrollEnabled = NO;
        _wkWebView.navigationDelegate = self;
        [_wkWebView.scrollView addObserver:self forKeyPath:contentSizeKey options:NSKeyValueObservingOptionNew context:nil];
        [self.contentView addSubview:_wkWebView];
    }
    return _wkWebView;
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{
    return nil;
}
- (void)removeObserverForWebViewContentSize {
    
    [_wkWebView.scrollView removeObserver:self forKeyPath:contentSizeKey];
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    if ([keyPath isEqualToString:contentSizeKey]) {
        CGFloat height = self.wkWebView.scrollView.contentSize.height;
        if (height > 0) {
            if (_wkWebViewHeight) {
                [self removeObserverForWebViewContentSize];//重点 ： 高度回调后把监听移除，不然会重复走这段代码 
                _wkWebView.frame = CGRectMake(0, 0, HHBWIDTH, height);
                self.wkWebViewHeight(height);
            }
        }
    }
}

+ (NSString *)identifier{
    return NSStringFromClass([self class]);
}

@end

• viewController代码

 CdConferenceGeneralizeCell *cell = [tableView dequeueReusableCellWithIdentifier:[CdConferenceGeneralizeCell identifier]];
        if (!cell) {
            cell = [[CdConferenceGeneralizeCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:[CdConferenceGeneralizeCell identifier]];
        }
        WS(weakSelf);
        [cell configuration:_allMeetDetailModel];
        cell.wkWebViewHeight = ^(CGFloat height) {
            _webViewH = height;
            [weakSelf.tableView reloadRowsAtIndexPaths:@[[NSIndexPath indexPathForRow:0 inSection:2]] withRowAnimation:UITableViewRowAnimationNone];
        };
        return cell;
        ```