我在将UIButton添加到UIBarButtonItem时遇到了已知问题。我尝试添加自动布局约束,如stackoveflow中建议的那样,但是我收到了下面描述的错误。
UIButton *sortButton = [UIButton buttonWithType:UIButtonTypeCustom];
[sortButton setFrame:CGRectMake(10, 0, 100, 30)];
[sortButton setTitle:@"Sort" forState:UIControlStateNormal];
[[sortButton titleLabel] setFont:[UIFont boldSystemFontOfSize:13]];
[sortButton setBackgroundImage:[UIImage imageNamed:@"backgroun-button.png"] forState:UIControlStateNormal];
[sortButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[sortButton addTarget:self action:@selector(sortCollection:) forControlEvents:UIControlEventTouchUpInside];
[sortButton applyNavBarConstraints:100 height:30];
[self setSortCollection:item];
[self setToolbarItems:[NSArray arrayWithObjects:self.sortCollection, nil]];
自动布局约束:
- (void)applyNavBarConstraints:(CGFloat)width height:(CGFloat)height
{
if (width == 0 || height == 0) {
return;
}
NSLayoutConstraint* w = [self.widthAnchor constraintEqualToConstant:width];
NSLayoutConstraint * h = [self.heightAnchor constraintEqualToConstant:height];
[w setActive:YES];
[h setActive:YES];
}
堆栈跟踪:
[LayoutConstraints] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x608000280af0 h=--& v=--& UIToolbar:0x7f85ca1327e0.width == 768 (active)>",
"<NSLayoutConstraint:0x6000002826c0 _UIToolbarContentView:0x7f85ca1307b0.trailing == UIToolbar:0x7f85ca1327e0.trailing (active)>",
"<NSLayoutConstraint:0x600000282580 H:|-(0)-[_UIToolbarContentView:0x7f85ca1307b0] (active, names: '|':UIToolbar:0x7f85ca1327e0 )>",
"<NSLayoutConstraint:0x600000285410 H:|-(0)-[_UIButtonBarStackView:0x7f85ca135660] (active, names: '|':_UIToolbarContentView:0x7f85ca1307b0 )>",
"<NSLayoutConstraint:0x600000285460 _UIButtonBarStackView:0x7f85ca135660.trailing == _UIToolbarContentView:0x7f85ca1307b0.trailing (active)>",
"<NSLayoutConstraint:0x600000285500 UIButton:0x7f85ca131b90'Sortieren'.width == 100 (active)>",
"<NSLayoutConstraint:0x608000280ff0 'UISV-canvas-connection' UILayoutGuide:0x6000001ba240'UIViewLayoutMarginsGuide'.leading == UIButton:0x7f85ca131b90'Sortieren'.leading (active)>",
"<NSLayoutConstraint:0x608000280d70 'UISV-canvas-connection' UILayoutGuide:0x6000001ba240'UIViewLayoutMarginsGuide'.trailing == UIButton:0x7f85ca131b90'Sortieren'.trailing (active)>",
"<NSLayoutConstraint:0x600000284f10 'UIView-leftMargin-guide-constraint' H:|-(0)-[UILayoutGuide:0x6000001ba240'UIViewLayoutMarginsGuide'](LTR) (active, names: '|':_UIButtonBarStackView:0x7f85ca135660 )>",
"<NSLayoutConstraint:0x600000285190 'UIView-rightMargin-guide-constraint' H:[UILayoutGuide:0x6000001ba240'UIViewLayoutMarginsGuide']-(0)-|(LTR) (active, names: '|':_UIButtonBarStackView:0x7f85ca135660 )>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x600000285500 UIButton:0x7f85ca131b90'Sortieren'.width == 100 (active)>
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
UIBarButtonSystemItemFlexibleSpace
,为什么你需要约束? - Reinier MelianUIBatButtonItem
,即它还为您的“_Sortieren_”按钮设置了前导和后续约束。因此,您不再可以设置宽度约束,就像您所做的那样。尝试不设置此约束,冲突应该会消失。 - Reinhard Männer