Ios 与top&;底部布局指南
从视图和controller.topLayoutGuide&controller.bottomLayoutGuide以编程方式设置NSLayoutconstraints时遇到一些问题 在viewDidLoad中使用此代码:Ios 与top&;底部布局指南,ios,autolayout,nslayoutconstraint,Ios,Autolayout,Nslayoutconstraint,从视图和controller.topLayoutGuide&controller.bottomLayoutGuide以编程方式设置NSLayoutconstraints时遇到一些问题 在viewDidLoad中使用此代码: _mainView.translatesAutoresizingMaskIntoConstraints = NO; [self.view addSubview:_mainView]; [self.view removeConstraints:self.view.constra
_mainView.translatesAutoresizingMaskIntoConstraints = NO;
[self.view addSubview:_mainView];
[self.view removeConstraints:self.view.constraints];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-0-[_mainView]-0-|" options:NSLayoutFormatAlignAllBaseline metrics:nil views:NSDictionaryOfVariableBindings(_mainView)]];
id top = self.topLayoutGuide;
id bottom = self.bottomLayoutGuide;
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[top]-0-[_mainView]-0-[bottom]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(top, _mainView, bottom)]];
[self.view layoutSubviews];
结果是:
(_mainView具有深灰色背景色)
如果我设置了与superview相关的约束,它将起作用:
_mainView.translatesAutoresizingMaskIntoConstraints = NO;
[self.view addSubview:_mainView];
[self.view removeConstraints:self.view.constraints];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-0-[_mainView]-0-|" options:NSLayoutFormatAlignAllBaseline metrics:nil views:NSDictionaryOfVariableBindings(_mainView)]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-0-[_mainView]-0-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(_mainView)]];
[self.view layoutSubviews];
我的错误在哪里?
视图控制器层次结构为uitabbarcontroller->uinavigationController->myViewController
解决了 错误是:
[self.view removeConstraints:self.view.constraints];
我用密码修改了密码
for(NSLayoutConstraint *c in self.view.constraints)
if(c.firstItem == _mainView || c.secondItem == _mainView)
[self.view removeConstraint:c];
它成功了。
无论如何,谢谢!;) 检查self.topLayoutGuide和self.bottomLayoutGuide是否为零。您可能忘记在Interface Builder中设置插座。已解决!!如果(c.firstItem==|u mainView | | c.secondItem==_mainView)[self.view removeConstraint:c];“我在(self.view.constraints中的NSLayoutConstraint*c)中使用了“[self.view removeConstraints:self.view.constraints];”行,那么它就起作用了。