为什么UIViewController在UINavigationBar下扩展，而UITableViewController却没有？ [英] Why does UIViewController extend under UINavigationBar, while UITableViewController doesn't?

问题描述

我有 UITabbarController ，其中包含 UINavigationController 。我有一个 UIView 的子类，我指定为 UIViewController的视图 在 navController 中。这是非常标准的东西，对吗？我是这样做的。

I have UITabbarController with UINavigationController in it. I have a subclass of UIView that I assign as the view of UIViewController in the navController. This is pretty standard stuff, right? This is how I do it

_productCategoryView = [[ProductCategoryView alloc] initWithFrame:self.view.frame];
self.view = _productCategoryView;

此视图有 UITableView as subView

_productCategoryTableView = [[UITableView alloc] initWithFrame:self.frame style:UITableViewStylePlain];
_productCategoryTableView.separatorStyle = UITableViewCellSeparatorStyleNone;
_productCategoryTableView.backgroundColor = [UIColor clearColor];
[self addSubview:_productCategoryTableView];

为了调试我设置 self.backgroundColor = [UIColor blueColor在视图上显示。

从 tableView 的上述初始化中，可能会认为视图和表的框架是一样的。但是当我在 iOS 7 中运行时，视图的原点设置在 UINavigationBar 之后。这是可以理解的，因为我在 UINavigationController 的子类中设置 self.navigationBar.translucent = YES; 。但我不明白的是桌子是如何坐在 navBar 的正下方？它不应该从（0,0）开始，它位于 navBar 之后？请参阅下面的屏幕截图 Scenario 1 。注意蓝色色调 navBar

From the above initialization of tableView one might think that the view's and table's frame is same. However when I run in iOS 7, the view's origin is set behind the UINavigationBar. This is understandable because I am setting self.navigationBar.translucent = YES; in my subclass of UINavigationController. But what I don't understand is how come the table is sitting just below the navBar? Shouldn't it also start from (0, 0) which is behind the navBar? See screenshot Scenario 1 below. Notice the blue hue behind navBar

现在，我推送另一个 viewController 在导航堆栈上，只需使用 [self.navigationController pushViewController .....] 。我再次有一个自定义 UIView ，其中包含 tableView 。但是我在这个表上面还有一个 UILabel ，再次进行调试，我给它一个 redColor 。这次我将标签的来源设置为与视图的几乎相同

Now, I push another viewController on the navigation stack, simply by using [self.navigationController pushViewController.....]. Again I have a custom UIView with a tableView in it. However I also have a UILabel above this table, and again for debugging, I gave it a redColor. This time I am setting the label's origin to be almost same as the view's

CGRect boundsInset = UIEdgeInsetsInsetRect(self.bounds, UIEdgeInsetsMake(10, 10, 10, 10));

CGSize textSize = [_titleLabel.text sizeWithFont:_titleLabel.font
                               constrainedToSize:CGSizeMake(boundsInset.size.width, MAXFLOAT)
                                   lineBreakMode:NSLineBreakByWordWrapping];
printSize(textSize);
_titleLabel.frame = CGRectMake(boundsInset.origin.x,
                               boundsInset.origin.y,
                               boundsInset.size.width,
                               textSize.height);

因此，按照上面的逻辑，标签应该是可见的，对吗？但这次不是。这次标签位于 navBar 之后。

So, going by the logic above, the label should be visible, right? But this time it's not. This time the label is behind the navBar.

注意，navBar背后的红色色调。

Notice, the red hue behind navBar.

我真的想在navBar下面一致地调整子视图。我的问题是

I would really like to align the subView below the navBar consistently. My questions are

1。 tableView如何自动偏移64像素（导航高度+ iOS 7中的状态栏），即使它的帧与视图相同？

2。为什么这不会发生在第二个视图中？

推荐答案

默认情况下，UITableViewController的视图会自动插入在iOS7中，它们不会从导航栏/状态栏下面开始。这是通过Interface Builder中UITableViewController的Attributes Inspector选项卡上的Adjust scroll view insets设置控制，或者是UIViewController的 setAutomaticallyAdjustsScrollViewInsets：方法。

By default, UITableViewController's views are automatically inset in iOS7 so that they don't start below the navigation bar/status bar. This is controller by the "Adjust scroll view insets" setting on the Attributes Inspector tab of the UITableViewController in Interface Builder, or by the setAutomaticallyAdjustsScrollViewInsets: method of UIViewController.

对于UIViewController的内容，如果您不希望其视图的内容在顶部/底部栏下方扩展，则可以使用接口顶部栏杆下方的延伸边缘/底部条形图下的设置生成器。这可以通过 edgesForExtendedLayout 属性访问。

For a UIViewController's contents, if you don't want its view's contents to extend under the top/bottom bars, you can use the Extend Edges Under Top Bars/Under Bottom Bars settings in Interface Builder. This is accessible via the edgesForExtendedLayout property.

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