ios - UISearchBar AutoLayout Error en la presentación de searchResultsController

objective-c

Question

Estoy intentando que UISearchBar + UISearchController funcione en Obj-C, siguiendo junto con el código de ejemplo de Apple aquí . No quiero configurar la barra de búsqueda en un encabezado de vista de tabla, como lo hacen en el ejemplo, entonces estoy estableciendo restricciones para pegarlo en la parte superior del controlador de vista principal. Esto funciona bien para el posicionamiento, pero cuando toco la barra de búsqueda e intenta presentar modalmente el controlador de vista de tabla de resultados ( searchResultsTVC ), arroja un error sobre las restricciones:

2015-02-01 00:36:47.539 Search-FeatureTest[15521:3760972] The view hierarchy is not prepared for the constraint: <NSLayoutConstraint:0x7fc911c77f90 UISearchBar:0x7fc911c6b880.left == UIView:0x7fc911c69b70.left>
When added to a view, the constraint''s items must be descendants of that view (or the view itself). This will crash if the constraint needs to be resolved before the view hierarchy is assembled. Break on -[UIView _viewHierarchyUnpreparedForConstraint:] to debug.
2015-02-01 00:36:47.539 Search-FeatureTest[15521:3760972] *** Assertion failure in -[UIView _layoutEngine_didAddLayoutConstraint:roundingAdjustment:mutuallyExclusiveConstraints:], /SourceCache/UIKit_Sim/UIKit-3318.16.14/NSLayoutConstraint_UIKitAdditions.m:560
2015-02-01 00:36:47.541 Search-FeatureTest[15521:3760972] *** Terminating app due to uncaught exception ''NSInternalInconsistencyException'', reason: ''Impossible to set up layout with view hierarchy unprepared for constraint.''
*** First throw call stack:
(
    0   CoreFoundation                      0x00000001047aef35 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x0000000104447bb7 objc_exception_throw + 45
    2   CoreFoundation                      0x00000001047aed9a +[NSException raise:format:arguments:] + 106
    3   Foundation                          0x00000001040645df -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 195
    4   UIKit                               0x0000000105215cf2 __120-[UIView(UIConstraintBasedLayout) _layoutEngine_didAddLayoutConstraint:roundingAdjustment:mutuallyExclusiveConstraints:]_block_invoke_2 + 177
    5   UIKit                               0x0000000105215be7 -[UIView(UIConstraintBasedLayout) _layoutEngine_didAddLayoutConstraint:roundingAdjustment:mutuallyExclusiveConstraints:] + 377
    6   UIKit                               0x0000000105215ea4 -[UIView(UIConstraintBasedLayout) _tryToAddConstraintWithoutUpdatingConstraintsArray:roundingAdjustment:mutuallyExclusiveConstraints:] + 30
    7   UIKit                               0x0000000105215fcc -[UIView(UIConstraintBasedLayout) _tryToAddConstraint:roundingAdjustment:mutuallyExclusiveConstraints:] + 243
    8   UIKit                               0x000000010521630b __50-[UIView(UIConstraintBasedLayout) addConstraints:]_block_invoke + 188
    9   Foundation                          0x0000000103fedd6e -[NSISEngine withBehaviors:performModifications:] + 155
    10  UIKit                               0x0000000105216240 -[UIView(UIConstraintBasedLayout) addConstraints:] + 263
    11  UIKit                               0x000000010520f112 -[_UISearchPresentationController presentationTransitionWillBegin] + 759
    12  UIKit                               0x0000000104ca00a7 __71-[UIPresentationController _initViewHierarchyForPresentationSuperview:]_block_invoke + 1398
    13  UIKit                               0x0000000104c9eb50 __56-[UIPresentationController runTransitionForCurrentState]_block_invoke + 175
    14  UIKit                               0x0000000104bbe331 _applyBlockToCFArrayCopiedToStack + 314
    15  UIKit                               0x0000000104bbe1ab _afterCACommitHandler + 516
    16  CoreFoundation                      0x00000001046e3dc7 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
    17  CoreFoundation                      0x00000001046e3d20 __CFRunLoopDoObservers + 368
    18  CoreFoundation                      0x00000001046d9b53 __CFRunLoopRun + 1123
    19  CoreFoundation                      0x00000001046d9486 CFRunLoopRunSpecific + 470
    20  GraphicsServices                    0x0000000107d7d9f0 GSEventRunModal + 161
    21  UIKit                               0x0000000104b9b420 UIApplicationMain + 1282
    22  Search-FeatureTest                  0x0000000103f19043 main + 115
    23  libdyld.dylib                       0x0000000106d3e145 start + 1
 )
libc++abi.dylib: terminating with uncaught exception of type NSException

Aquí está el código donde inicializo el controlador de búsqueda y las restricciones de la barra de búsqueda:

- (void)viewDidLoad {
    [super viewDidLoad];

    self.searchResultsTVC = [[SearchResultsTVC alloc]init];
    self.allObjects = [NSMutableArray arrayWithArray:@[@"A", @"AA", @"ABBA", @"B", @"BOB", @"C", @"D", @"E", @"F", @"G", @"H"]];

    self.searchController = [[UISearchController alloc]initWithSearchResultsController:self.searchResultsTVC];
    [self.searchController setSearchResultsUpdater:self];
    [self.searchController setDelegate:self];

    [self.searchController.searchBar setDelegate:self];
    [self.view addSubview:self.searchController.searchBar];

    //constraints for searchBar
    [self.searchController.searchBar setTranslatesAutoresizingMaskIntoConstraints:NO];
    UISearchBar *searchBar = self.searchController.searchBar;
    id topLayoutGuide = self.topLayoutGuide;

    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[searchBar]|" options:NSLayoutFormatDirectionLeftToRight metrics:nil views:NSDictionaryOfVariableBindings(searchBar)]];
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[topLayoutGuide][searchBar]" options:NSLayoutFormatDirectionLeftToRight metrics:nil views:NSDictionaryOfVariableBindings(topLayoutGuide, searchBar)]];

}

Answer 1

Solución: (En respuesta a Darmen)

Como lo sugirió Zoo, agregué una vista de contenedor en el constructor de interfaz, restringida a la parte superior y a los lados de la supervista, con una altura de 44.

Luego coloco la barra de búsqueda en la vista de esta manera:

- (void)viewDidLoad {
    [super viewDidLoad];

    self.searchController = [[UISearchController alloc]initWithSearchResultsController:<Your SearchResultsController>];
    [self.searchController setSearchResultsUpdater:self];
    [self.searchController setDelegate:self];

    [self.searchController.searchBar setDelegate:self];

    [self.searchBarContainer addSubview:self.searchController.searchBar];

    self.definesPresentationContext = YES;
}