我正在开发一个必须同时支持iOS 8和iOS 7.1的项目。现在我遇到的问题只出现在iOS 7.1上,但在iOS 8上运行正常。我有一个ViewController,它包含tableView和tableHeaderView中的自定义视图。我将发布如下代码。所有约束都以编程方式添加。
//查看控制器。
-(void)viewDidLoad
{
[super viewDidLoad];
self.commentsArray = [NSMutableArray new];
[self.commentsArray addObject:@"TEST"];
[self.commentsArray addObject:@"TEST"];
[self.commentsArray addObject:@"TEST"];
[self.commentsArray addObject:@"TEST"];
[self.commentsArray addObject:@"TEST"];
[self.commentsArray addObject:@"TEST"];
[self.view addSubview:self.masterTableView];
self.masterTableView.tableHeaderView = self.detailsView;
[self.view setNeedsUpdateConstraints];
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self.view layoutIfNeeded];
}
//Table view getter
- (UITableView *)masterTableView
{
if(!_masterTableView)
{
_masterTableView = [UITableView new];
_masterTableView.translatesAutoresizingMaskIntoConstraints = NO;
_masterTableView.backgroundColor = [UIColor greyColor];
_masterTableView.delegate = self;
_masterTableView.dataSource = self;
_masterTableView.separatorStyle = UITableViewCellSeparatorStyleNone;
_masterTableView.showsVerticalScrollIndicator = NO;
_masterTableView.separatorInset = UIEdgeInsetsZero;
}
return _masterTableView;
}
-(void)updateViewConstraints
{
NSDictionary *views = @{
@"table" : self.masterTableView,
@"details" : self.detailsView,
};
NSDictionary *metrics = @{
@"width" : @([UIScreen mainScreen].applicationFrame.size.width)
};
//Table view constraints
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-0-[table]-0-|" options:0 metrics:0 views:views]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-0-[table]-0-|" options:0 metrics:0 views:views]];
//Details View
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-0-[details(width)]-0-|" options:0 metrics:metrics views:views]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-0-[details]-0-|" options:0 metrics:metrics views:views]];
}
//Details View Getter
- (DetailsView *)detailsView
{
if(!_detailsView)
{
_detailsView = [[DetailsView alloc]initWithFrame:CGRectMake(0, 0, 0, 100)];
_detailsView.backgroundColor = [UIColor orangeColor];
return _detailsView;
}
现在详细信息视图包含一些基本的子视图,这些子视图都来自UIView,详细信息视图本身来自更一般的超类。我将发布如下代码。
//Parent View
@interface ParentView (): UIView
- (instancetype)init
{
self = [super init];
if (self)
{
[self setupViews];
}
return self;
}
- (void)setupViews
{
[self addSubview:self.publishedTimeView];
}
- (void)updateConstraints
{
NSDictionary *views = @{
@"time" : self.publishedTimeView,
};
// Header with published video time
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[time]-10-|" options:0 metrics:0 views:views]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[time(11)]" options:0 metrics:0 views:views]];
[super updateConstraints];
}
//Getter for the timePublished view added to the detail view. Will not post all its related code for //the sake of brevity.
- (TimePublishedDetailView *)publishedTimeView
{
if(!_publishedTimeView)
{
_publishedTimeView = [TimePublishedDetailView new];
_publishedTimeView.translatesAutoresizingMaskIntoConstraints = NO;
}
return _publishedTimeView;
}
//Child View (or the detailsView) of the view controller.
@interface DetailsView : ParentView
@implementation RecordingDetailsView
- (void)updateConstraints
{
NSDictionary *views = @{
@"time" : self.publishedTimeView,
};
//Vertical alignment of all views
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-20-[time]" options:0 metrics:nil views:views]];
[super updateConstraints];
}
- (void)setModel:(DetailViewModel *)model
{
self.publishedTimeView.date = model.dateTime;
[self setNeedsUpdateConstraints];
[self layoutSubviews];
}
现在在iOS 8上看起来像这样:
但是在iOS 7.1上,这会出现此错误消息:
“异常:执行-layoutSubviews后仍然需要自动布局.UITableView的-layoutSubviews实现需要调用super”
我已经使用Google搜索并在我的布局调用中使用代码来查看是否可以解决问题,但到目前为止都没有成功。如果有人可以发布一些关于如何解决这个问题的技巧或建议,我会非常感激。
答案 0 :(得分:2)
我知道这个问题已经过时了,但我最近遇到了类似的问题,经过大量谷歌搜索,尝试失败后,我在this answer的帮助下进行了一些改动。
只需将此类别添加到您的项目中,只需拨打[UITableView fixLayoutSubviewsMethod];
一次(我建议在AppDelegate
内)。
#import <objc/runtime.h>
#import <objc/message.h>
@implementation UITableView (FixUITableViewAutolayoutIHope)
+ (void)fixLayoutSubviewsMethod
{
Method existing = class_getInstanceMethod(self, @selector(layoutSubviews));
Method new = class_getInstanceMethod(self, @selector(_autolayout_replacementLayoutSubviews));
method_exchangeImplementations(existing, new);
}
- (void)_autolayout_replacementLayoutSubviews
{
[super layoutSubviews];
[self _autolayout_replacementLayoutSubviews]; // not recursive due to method swizzling
[super layoutSubviews];
}
@end