iOS端WEEX的list组件中cell会清空subviews

前端说的list 是weexsdk在WXListComponent 中的WXTableView
继承自UITableView。

在下面方法中 调用 _unloadViewWithReusing会清空cell中的子视图

- (void)tableView:(UITableView *)tableView didEndDisplayingCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
    WXLogDebug(@"Did end displaying cell:%@, at index path:%@", cell, indexPath);
    NSArray *visibleIndexPaths = [tableView indexPathsForVisibleRows];
    if (![visibleIndexPaths containsObject:indexPath]) {
        if (cell.contentView.subviews.count > 0) {
            UIView *wxCellView = [cell.contentView.subviews firstObject];
            // Must invoke synchronously otherwise it will remove the view just added.
            WXCellComponent *cellComponent = (WXCellComponent *)wxCellView.wx_component;
            if (cellComponent.isRecycle) {
                [cellComponent _unloadViewWithReusing:YES];
            }
        }
    }
}

- (void)_unloadViewWithReusing:(BOOL)isReusing
{
    WXAssertMainThread();
    
    if (isReusing && self->_positionType == WXPositionTypeFixed) {
        return;
    }
    
    [self viewWillUnload];
    
    _view.gestureRecognizers = nil;
    
    [self _removeAllEvents];
    
    if (self.ancestorScroller) {
        [self.ancestorScroller removeStickyComponent:self];
        [self.ancestorScroller removeScrollToListener:self];
    }
    
    for (WXComponent *subcomponents in [self.subcomponents reverseObjectEnumerator]) {
        [subcomponents _unloadViewWithReusing:isReusing];
    }
    
    if ([_view superview]) {
        [_view removeFromSuperview];
    }
    
    if (self->_isTemplate && self.attributes[@"@templateId"]) {
        [[WXSDKManager bridgeMgr] callComponentHook:self.weexInstance.instanceId componentId:self.attributes[@"@templateId"] type:@"lifecycle" hook:@"detach" args:nil competion:nil];
    }
    _view = nil;
    [_layer removeFromSuperlayer];
    _layer = nil;
    
    [self viewDidUnload];
}

其中isRecycle 应该是官方文档中的 cell在iOS中对应的是WXCellComponent

官方文档关于cell 的说明

经过测试 我们工程中在cell中的自定义component不会被释放只有自定义的commponent的view会被cell移除并释放
所以在自定义的component中强引用view在loadview中重新赋值即可

- (UIView *)loadView
{
    if (_imageView) {
        return _imageView;
    }
    UIIMageView* imageView = [[UIIMageView alloc] init];
    imageView.weexSDKInstance = self.weexInstance;
    return imageView;
}