So könnten Sie im Code verfahren.
Grundsätzlich müssen Sie:
a) in updateViewConstraints
in Ihrem UIViewController
die entsprechenden NSLayoutConstraint
s für die gegebene Orientierung konfigurieren.
b) Rufen Sie [self.view setNeedsUpdateConstraints]
an, wenn sich die Schnittstelle dreht.
Unten ist eine ViewController-Implementierung und eine Kategorie in UIView mit Hilfsmethoden.
@interface ConstraintsViewController()
@property (nonatomic, weak) IBOutlet UIView *upperOrLeftView, *lowerOrRightView;
@end
@implementation ConstraintsViewController
-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
[super willAnimateRotationToInterfaceOrientation:toInterfaceOrientation duration:duration];
[self.view setNeedsUpdateConstraints];
}
-(void)updateViewConstraints {
[super updateViewConstraints];
[self.view removeConstraintsRelatingToItems:@[self.upperOrLeftView,self.lowerOrRightView]];
if(UIInterfaceOrientationIsPortrait(self.interfaceOrientation)) {
[self.view constrainSubview:self.upperOrLeftView usingEdgeInsets:UIEdgeInsetsMake(0, 0, -1, 0)];
[self.view constrainSubview:self.lowerOrRightView usingEdgeInsets:UIEdgeInsetsMake(-1, 0, 0, 0)];
[self.view constrainSubviewsTopToBottom:@[self.upperOrLeftView, self.lowerOrRightView]];
}
else {
[self.view constrainSubview:self.upperOrLeftView usingEdgeInsets:UIEdgeInsetsMake(0, 0, 0, -1)];
[self.view constrainSubview:self.lowerOrRightView usingEdgeInsets:UIEdgeInsetsMake(0, -1, 0, 0)];
[self.view constrainSubviewsLeftToRight:@[self.upperOrLeftView, self.lowerOrRightView]];
}
}
@end
Setzen Sie dieses in UIView + Constraints.h
@interface UIView (Constraints)
-(void)removeConstraintsRelatingToItems:(NSArray*)items;
-(void)constrainSubview:(UIView*)subview usingEdgeInsets:(UIEdgeInsets)insets;
-(void)constrainSubviewsLeftToRight:(NSArray*)subviews;
-(void)constrainSubviewsTopToBottom:(NSArray*)subviews;
@end
Dies ist UIView + Constraints.m
@implementation UIView (Constraints)
-(void)removeConstraintsRelatingToItems:(NSArray *)items {
for(NSLayoutConstraint *constraint in self.constraints) {
if([items containsObject:constraint.firstItem] || [items containsObject:constraint.secondItem]) {
[self removeConstraint:constraint];
}
}
}
/** Set up constraints to flow the subviews from top to bottom and with equal heights */
-(void)constrainSubviewsTopToBottom:(NSArray*)subviews {
if(subviews.count > 1) {
UIView *anchorView = subviews[0];
for(int i = 1; i < subviews.count; i++) {
UIView *view = subviews[i];
NSLayoutConstraint *heightConstraint = [NSLayoutConstraint constraintWithItem:anchorView attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:view attribute:NSLayoutAttributeHeight multiplier:1.0 constant:0.0];
NSLayoutConstraint *edgesConstraint = [NSLayoutConstraint constraintWithItem:anchorView attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:view attribute:NSLayoutAttributeTop multiplier:1.0 constant:0.0];
[self addConstraints:@[heightConstraint, edgesConstraint]];
anchorView = view;
}
}
}
/** Set up constraints to flow the subviews from left to right and with equal widths */
-(void)constrainSubviewsLeftToRight:(NSArray*)subviews {
if(subviews.count > 1) {
UIView *anchorView = subviews[0];
for(int i = 1; i < subviews.count; i++) {
UIView *view = subviews[i];
NSLayoutConstraint *widthConstraint = [NSLayoutConstraint constraintWithItem:anchorView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:view attribute:NSLayoutAttributeWidth multiplier:1.0 constant:0.0];
NSLayoutConstraint *edgesConstraint = [NSLayoutConstraint constraintWithItem:anchorView attribute:NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:view attribute:NSLayoutAttributeLeft multiplier:1.0 constant:0.0];
[self addConstraints:@[widthConstraint, edgesConstraint]];
anchorView = view;
}
}
}
/**
Set up constraints to anchor the various edges of the subview to it's superview (this view) using the provided insets.
Any inset set to < 0.0 means that edge is ignored;
*/
-(void)constrainSubview:(UIView*)subview usingEdgeInsets:(UIEdgeInsets)insets {
if(insets.top >= 0.0) {
[self addConstraint:[NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeTop multiplier:1.0 constant:insets.top]];
}
if(insets.right >= 0.0) {
[self addConstraint:[NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeRight multiplier:1.0 constant:-insets.right]];
}
if(insets.bottom >= 0.0) {
[self addConstraint:[NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeBottom multiplier:1.0 constant:-insets.bottom]];
}
if(insets.left >= 0.0) {
[self addConstraint:[NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeLeft multiplier:1.0 constant:insets.left]];
}
}
@end
Ich erhalte diese Fehlermeldung: „Kein sichtbarer @interface für 'UIView spricht der Wähler‚constrainSubview: usingEdgeInsets:‘“ – Homam
@Homam Sie die Einschränkungen Kategorie auf UIView hinzugefügt haben? –
Zum Testen habe ich ein Beispielprojekt mit SingleView-Anwendung erstellt. Kopierte den gesamten Code in ViewController. – Homam