如何在父视图上添加子视图控制器的视图

Question

如何在父视图上添加子视图控制器的视图

7

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    ChildViewController *childviewcontroller = [[ChildViewController alloc] initWithNibName:@"ChildViewController" bundle:nil];


    [self addChildViewController:childviewcontroller];
    [self.view addSubview:childviewcontroller.view];
    [childviewcontroller willMoveToParentViewController:self];
    UIView *cview = [[UIView alloc] init];
    cview = childviewcontroller.view;
    [self.view removeConstraints:self.view.constraints];

    NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(cview);
    [self.view addConstraints:[NSLayoutConstraint 
                                constraintsWithVisualFormat:@"H:|-[cview]-|" 
                                                    options:0 metrics:nil                                        
                                                    views:viewsDictionary]];

}

我希望在父视图上添加子视图控制器视图。添加后，我设置了约束，但对我没有起作用。

我也收到了这样的警告

2013-07-25 10:47:30.564 neenah[1105:c07] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. 
    Try this: (1) look at each constraint and try to figure out which you don't expect; 
    (2) find the code that added the unwanted constraint or constraints and fix it. 
    (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't 
    understand, refer to the documentation for the UIView 
    property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x9256c90 H:|-(NSSpace(20))-[UIView:0x9256a00]   (Names: '|':UIView:0x92557a0 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x755d690 h=--& v=--& H:[UIView:0x9256a00(320)]>",
    "<NSAutoresizingMaskLayoutConstraint:0x755d5a0 h=--& v=--& UIView:0x9256a00.midX == + 160>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x9256c90 H:|-(NSSpace(20))-[UIView:0x9256a00]   (Names: '|':UIView:0x92557a0 )>

Break on objc_exception_throw to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2013-07-25 10:47:30.567 neenah[1105:c07] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x9256bb0 H:[UIView:0x9256a00]-(NSSpace(20))-|   (Names: '|':UIView:0x92557a0 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x7561690 h=--- v=--- H:[UIWindow:0x92527c0(320)]>",
    "<NSAutoresizingMaskLayoutConstraint:0x755fe50 h=-&- v=-&- UIView:0x92557a0.width == UIWindow:0x92527c0.width>",
    "<NSAutoresizingMaskLayoutConstraint:0x755d690 h=--& v=--& H:[UIView:0x9256a00(320)]>",
    "<NSAutoresizingMaskLayoutConstraint:0x755d5a0 h=--& v=--& UIView:0x9256a00.midX == + 160>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x9256bb0 H:[UIView:0x9256a00]-(NSSpace(20))-|   (Names: '|':UIView:0x92557a0 )>

Break on objc_exception_throw to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

- Dhiyanes KaeYes

你只需要加上这一行代码 [self.view addSubview:childviewcontroller.view]; - Puneet Sharma

addChildViewController在iOS5中用于viewController的包含，这将使您轻松创建自己的NavigationCotrollers或TabControllers，它仅在iOS5中可用。您需要这样的东西吗？如果不需要，请删除此行。 - Puneet Sharma

我需要删除哪一行 @Puneet - Dhiyanes KaeYes

@Puneet 不，由于他正在将子视图控制器的视图作为当前控制器视图的子视图添加视图，因此他_绝对应该保留_“addChildViewController”和“didMoveToParentViewController”调用的自定义容器调用。如果他要支持iOS 5.0之前的版本，那么可以放心，在运行iOS 5（及更高版本）时才进行方法调用的运行时检查。但显然，他正在使用自动布局，这是iOS 6及以上版本的功能，因此他应该进行容器调用。 - Rob

是的，Rob，你说得完全正确。我的错，我有点混淆了。谢谢你的解释。 - Puneet Sharma

显示剩余2条评论

1个回答

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- Rob · Accepted Answer

几点观察：

您应该关闭 translatesAutoresizingMaskIntoConstraints：

childviewcontroller.view.translatesAutoresizingMaskIntoConstraints = NO;

你应该也定义垂直方向的约束：

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-[cview]-|" 
                                                                  options:0
                                                                  metrics:nil                                        
                                                                    views:viewsDictionary]];

与你的问题无关，你不需要为创建[[UIView alloc] init]。你立刻就将它丢弃了。
我不确定为什么要删除self.view的约束条件。(我猜想你这样做是因为在测试过程中感到很头疼。)你不必这样做。但如果你在这里有其他事情让你认为你需要这样做，请告诉我们是什么。
当添加一个子控制器时，应该调用didMoveToParentViewController而不是willMoveToParentViewController。addChildViewController会自动调用willMoveToParentViewController，你只需要使用didMove...这个方法即可。

因此：

- (void)viewDidLoad {
    [super viewDidLoad];

    // instantiate the view controller

    ChildViewController *childViewController = [[ChildViewController alloc] initWithNibName:@"ChildViewController" bundle:nil];

    // or you can instantiate using storyboard
    //
    // ChildViewController *child = [self.storyboard instantiateViewControllerWithIdentifier:@"ChildIdentifier"];

    // now do the view controller containment calls to update the view controller hierarchy and add the view as appropriate

    [self addChildViewController:childViewController];
    childViewController.view.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:childViewController.view];
    [childViewController didMoveToParentViewController:self];
    UIView *childView = childViewController.view;

    NSDictionary *views = NSDictionaryOfVariableBindings(childView);
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[childView]-|" options:0 metrics:nil views:views]];
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-[childView]-|" options:0 metrics:nil views:views]];
}